Overview

The SIBER Workshop convened an international, interdisciplinary group of scientists at the National Institute of Oceanography in Goa, India to:

Chlorophyll in the Indian Ocean (boreal winter/ austral summer). SeaWIFS.

Review the state of our knowledge and scientific understanding of the biogeochemical and ecological dynamics of the Indian Ocean in relation to physical oceanographic variability; Identify prominent gaps in our understanding especially as they pertain to the role of physical and ecological processes in regulating biogeochemical cycles and the carbon cycle in particular; Formulate a plan for the implementation of a biogeochemical and ecological observational and modeling research program that leverages and substantially enhances the planned CLIVAR/GOOS Indian Ocean observing system. The SIBER Workshop is designed to elicit maximum interaction among the participants.

Details

Seven kilometers west of the Indian state of Goa’s capital Panajim (Panaji), Dona Paula Beach is nestled on the southern side of the rocky headlands that divide the Zuari and Mandovi estuaries. Providing a good view of the Mormugao harbor, this beach is fringed by palm trees and casuarina groves. The proximity of the beach to the capital city makes it a popular tourist sight.

This flyer in PDF format is a third annoucement and provides information on the workshop goals, preliminary program and location/date details.

(Screen Quality - 285 KB PDF)
(Print Quality - 1.2 MB PDF)

The workshop was held in Goa, the beautiful state on the west coast of India. Goa is well known for its beaches, its pleasant climate, its scenic splendor and its wonderful culture, a blend of the East and the West.

Workshop Venue
National Institute of Oceanography
Dona Paula - 403 004, Goa, India
EPABX: +91 (0) 832-2450450
Fax: +91 (0) 832 - 2450602 & 2450603
Email: ocean@nio.org

The National Institute of Oceanography (NIO) is one of the constituent laboratories of the Council of Scientific & Industrial Research – a R&D organization in India with a network of 38 laboratories in different fields of science and technology. NIO was established on 1 January 1966 following the International Indian Ocean Expedition in the 1960s. NIO has grown today into a large oceanographic laboratory with a focus on oceanography of the waters around India. While the headquarters of the Institute is at Dona Paula Beach, Goa, NIO has regional centers located at Kochi, Mumbai (Bombay) and Visakhapatnam.

Program

Overview

• Keynote speakers will present overviews and updates on the latest discoveries in the Indian Ocean involving ecological and biogeochemical variability as it relates to the carbon cycle and physical forcing
• Invited presentations will review the current status of the CLIVAR/GOOS Indian Ocean observing system and plans for the future (note: All speakers will be allocated a 25 minute time slot and will be asked to leave 5 minutes for questions)
• Working group breakout sessions
• Poster presentations
• Group banquet and cultural activities

Download Agenda as PDF

Day 0 (Monday 2nd October)
18:00-20:00	Reception (optional) and Welcome Desk (registration, agenda, abstracts)
Day 1 (Tuesday 3rd October)
8:00-9:00	Registration
9:00-9:05	Saraswati Vandana: Prayer for the Goddess of Learning
9:05-9:10	S.R. Shetye: Welcome to NIO
9:10-9:20	R. R. Hood: Introduction & Background of SIBER
9:20-9:25	Traditional Lighting of Lamps
9:25-9:40	Inaugural Address by His Excellency S.C. Jamir, the Governor of Goa
9:40-9:45	S.W.A. Naqvi: Vote of Thanks
9:45-10:10	Tea Break
10:10-10:25	Workshop Sponsors: Comments
10:25-10:40	Raleigh Hood & Wajih Naqvi: Overview of the agenda, goals and charge to workshop participants
Session 1. (Review the state of our knowledge–Atmosphere-ocean interactions, physics and climate) Presentations focusing on recent discoveries in the Indian Ocean related to atmosphere-ocean interaction, linkages to global climate and the physical response of the IO to variability spanning seasonal to decadal and longer time-scales.
10:40-11:05	B.N. Goswami (Increasing trend of extreme rain events over central India: Role of the Indian Ocean)
11:05-11:30	Jay McCreary (Physical processes that impact biological activity in the Indian Ocean at climatological and intraseasonal time scales) Julian P. McCreary, Jr., IPRC/SOEST, University of Hawaii, POST Bldg. 401, 1680 East West Roa, Honolulu, Hawaii 96822 USA jay@hawaii.edu Keywords: shallow overturning cells, upwelling, subduction, mixed-layer thickness, intraseasonal variability Two aspects of the wind-driven circulation in the Indian Ocean (IO) that strongly affect biological activity are reviewed, namely, the IO's shallow overturning cells, and variability in mixed-layer thickness.  The former is biologically important because the cells supply the subsurface, nutrient-rich water that surfaces in upwelling regions.  The latter is important through its influence on the nutrient supply in the euphotic zone and the amount of light experienced by phytoplankton. The IO's shallow overturning cells consist of downwelling (subduction) at southern midlatitudes, northward flow within the thermocline, near-surface southward flow, and upwelling in the tropics and northern ocean that closes the circulations.  There are two primary cells: the Cross-Equatorial Cell closed by upwelling off Somalia, Oman, and the southern tip of India; and the Subtropical Cell closed by upwelling from 5°-10°S in the western and central ocean.  These cells differ markedly from their counterparts in the Pacific and Atlantic Oceans (the North and South Subtropical Cells), which are roughly symmetric about the equator with upwelling confined to the eastern, equatorial ocean, the difference a consequence of the nature of the IO's wind field (e.g., the lack of mean, equatorial easterlies).  A third IO cell resembles the Atlantic and Pacific cells in that it is closed by upwelling in the eastern, near-equatorial ocean off Sumatra/Java; however, it is typically much weaker than the primary cells, attaining appreciable amplitudes only during IO dipole (IOD) events. The biological impact of the mixed-layer thickness is apparent in the Arabian Sea, where the intense, seasonally reversing, monsoon winds result in thicknesses that vary from being very thin (~10 m during intermonsoon periods) to very thick (100 m or more during the monsoons).  Changes in mixed-layer thickness forced by intraseasonal winds also impact biology, both in the Arabian Sea and in the 5°-10°S upwelling band.
11:30-11:55	Raghu Murtugudde (Low-frequency climate variability and Indian Ocean biogeochemistry) Raghu Murtugudde ESSIC, University of Maryland, College Park, MD USA ragu@essic.umd.edu Keywords: Indian Ocean, Climate, Biological Interactions, Observational Needs The unique character of the Indian Ocean is the landmass to the North and the seasonally reversing monsoons. These lead to a unique combination of negligible equatorial upwelling and a lack of significant ventilation in the Northern Indian Ocean in addition to the reversing surface and subsurface currents. The Arbian Sea and the Bay of Bengal while subject to fairly similar wind forcing, experience drastically different freshwater fluxes. The reversing monsoons generate a wind-stress curl and Ekman pumping in the Southern Tropical Indian Ocean with a thermocline ridge which generates the largest interannual physical and biogeochemical variability despite the much-publicized IODZM. Seasonal to interannual and longer time-scale variabilities in the physical variability is discussed in the context of biogeochemical observational requirements and spatio-temporal scales that must be captured by any observational network.
11:55-12:10	Tea Break
Session 2. (Review the state of our knowledge–Nutrient cycling and limitation) Presentations that will provide a review of the state of our knowledge of the IO basin as it relates to nutrient cycling and limitation.
12:10–12:35	M. Dileep Kumar (Nutrients in the Indian Ocean) M. Dileep Kumar, National Institute of Oceanography, Dona Paula, Goa 403 004, India dileep@nio.org Keywords: nutrients, productivity, strtification, aerosols, North Indian Ocean Nutrients supplies are largely influenced by monsoon winds that appear to be more effective in the Arabian Sea than the Bay of Bengal. Summer monsoon upwelling and winter convection pump nutrients into the euphotic zone in the respective seasons significantly in the northern and western regions of the Arabian Sea. The sedimentary supplies are not well known. While leakage of fertilizers to coastal ocean is theoretically estimated to be significant the ground reality is unknown. Although nitrate addition through deposition of aerosols may not influence the surface production that of iron or other metals appears to have a significant control. In both the basins the nutrient supplies from the deep are regionally variable as could be deduced from satellite chlorophyll images. Both external (with poor knowledge of exact transports by rivers) and internal supplies seem to be minimal since the dust deposition over the Bay from the atmosphere is less and that entrainment is severely inhibited by the barrier layer. The disproportionate accumulation of elemental nitrogen (compared to Argon) in subsurface layers indicates that excess nitrogen must have come from underestimated nitrogen fixation or laterally transported after release from marginal sediments. The relevant information from the Bay is meager. Under hypoxia conditions and formation of low salinity lens at surface the Indian shelf waters experience nitrate starvation leading to formation of nitrogen fixing blooms. In the subsurface layer N:P significantly deviates from Redfield's ratio.
12:35–13:00	Doug Capone (Nitrogen Fixation in the Indian Ocean N cycle) Douglas G. Capone, Wrigley Institute and Department of Biological Sciences, University of Southern California, Los Angeles, USA capone@usc.edu Several lines of geochemical evidence including nutrient stoichiometry and stable isotope mass balances have revealed biological nitrogen fixation as a critical and quantitatively important process in the marine nitrogen cycle. It offsets the removal of nitrogen by denitrification and provides a source of new nitrogen which may be coupled to the sequestration of carbon. However, global and basin scale rates of nitrogen fixation remain poorly constrained due to undersampling both with respect to the areal and temporal extent of direct studies. This is particularly the case for the Indian Ocean. There is ongoing debate as to how closely coupled nitrogen fixation and denitrification are. Geochemical evidence is also accumulating that nitrogen fixation may be associated with oxygen minimum zones of the tropical ocean as well. This is of particular relevance in the Arabian Sea (AS). While several distinct agents of N2 fixation have been previously characterized such as the non-heterocystous cyanobacterium, Trichodesmium spp., a variety of new sources have been recently recognized. These include two distinct groups of single celled cyanobacteria, alpha and gamma proteobacteria and heterocystous cyanobacterial symbionts of certain oceanic diatoms. Each group has unique ecological and physiological requirements. Again, we are just beginning to discern the relative contributions of these diverse diazotrophs. Specific controls on nitrogen fixation likely vary across basin as a result of the modes of external forcing (e.g. seasonal monsoons and upwelling) and inputs. A variety of nutrients, including iron, phosphorus and silicon, may limit nitrogen fixation at broad scales. Other important routes of input of key nutrients to the Indian Ocean include riverine discharge and aeolian flux.
13:00-14:00	Lunch
14:00-14:25	Margie Mulholland (N2 fixation: Does physiology matter?) Margaret R. Mulholland, Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, VA 23529-0276, USA mmulholl@odu.edu Nitrogen fixation is now recognized as an important process in the world's oceans. Trichodesmium and other diazotrophs are common in tropical and subtropical oligotrophic waters including the Indian Ocean, where they introduce new N and potentially alleviating system-wide N-limitation. While we know much more about N2 fixation by Trichodesmium, unicellular diazotrophs may have a more cosmopolitan global distribution and therefore may have a greater contribution to total marine N2 fixation. Although new production by marine N2 fixers has been quantified in recent years in sectors of the Atlantic and Pacific Oceans, rate measurements from the Indian Ocean are limited, despite the fact that geochemical predictions suggest that new N inputs from N2 fixation in this region may be quite high. Further, coastal areas, include those influenced by riverine and estuarine discharge can harbor N2 fixers different from those characteristic of oligotrophic regions and their contributions to N and C fluxes in coastal areas have not been widely assessed anywhere. Physiologically, estimates of growth rates, N2 fixation rates and nitrogen and carbon based doubling times all vary widely within and among studies of Trichodesmium. Possible reasons for these widely varying rates include metabolic flexibility, and rapid recycling of elements, particularly N and P and possibly Fe. Studies suggest that up to 90% of the recently fixed N2 can be rapidly regenerated as ammonium and dissolved organic nitrogen. This regenerated N is then available to support the autotrophic or heterotrophic growth of other microorganisms and so can affect ecosystem structure and function. In several systems, including the Arabian Sea, potentially harmful dinoflagellate blooms can accompany or follow intense periods of N2 fixation. Alternatively, diatom-diazotroph symbioses may be promoted in coastal areas such as river plumes where Si is abundant. The fate of new production from N2 fixation is likely different depending on the dominant diazotroph, but has not been broadly examined and the stoichiometric relationships between C, N, P, and Fe uptake and regeneration may be more complicated than previously thought. Further complicating an already complex problem is that anthropogenic factors may contribute to enhanced N inputs from N2 fixation due to changes in riverine inputs, aeolian fluxes, or directly through CO2 effects on the growth and productivity of diazotrophs in the coming decades.
14:25-14:50	Jim Moffett (Is the Arabian Sea Fe Limited?) James Moffett, Woods Hole Oceanographic Institution, Woods Hole, MA USA jmoffett@whoi.edu The prevailing view is that primary production in the Arabian Sea is limited by grazing. This may be true for much of the year, but here, a case is made that Fe limitation is important during the SW monsoon. Since C export is greatest at this time, factors controlling primary production are very important. Results from a 2004 cruise on the Sagar Kanya, combined with modelling data of Jerry Wiggert and a reinterpretation of JGOFS data have led to this interpretation.
14:50–15:15	Mitsuo Uematsu (Atmospheric dust and Fe transport and deposition variability) Mitsuo Uematsu, Ocean Research Institute, The University of Tokyo, Tokyo, Japan uematsu@ori.u-tokyo.ac.jp Keywords: mineral dust, iron fertilization, atmospheric input, primary production, SOLAS Iron containing mineral dust is transported from land through the atmosphere to the oceans, affecting marine biogeochemistry and hence having feedback effects on climate and dust production. In the case of the North Pacific Ocean, aeolian dust and gaseous and particulate pollutants from the Asian continent are transported eastward and deposited heavily over the western North Pacific region, especially during spring. From the view of biogeochemical cycles, the atmospheric deposition of aerosols containing iron and other essential trace elements may contribute in sustaining primary productivity of phytoplankton, food web structure in seawater and chemical properties of marine atmosphere over the HNLC (High Nutrient Low Chlorophyll) region. To test the iron hypothesis, in-situ iron enrichment experiments (SEEDS I and SEEDS II) were performed in the western subarctic Pacific in summer 2001 and 2004. About 350 kg of iron and the inert chemical tracer sulfur hexafluoride were introduced into a surface mixed layer. During SEEDS, the rapid and very high accumulation of phytoplankton biomass was caused by a floristic shift from pennate diatoms to fast- growing centric diatoms and by shallow surface mixed layer (10-20m). The blooming of diatoms resulted in a marked consumption of macronutrients. SEEDS II was conducted in the same western subarctic Pacific region, which was designed to characterize the evolution of the fertilized patch over a longer time scale (1 month) and with a greater range of parameters than measured during SEEDS I. The preliminary results from SEEDS II showed that the iron-initiated bloom was much less intense than observed in SEEDS I. Chlorophyll-a concentrations increased only 2 to 3 times over initial values, and the drawdown of nutrients was small. On the effects of surface mixed layer depth, meso-zooplankton grazing and seed stocks of fast growing diatoms made the difference of biological and chemical responses between SEEDS I and SEEDS II. Recently, the relationship between Asian dust events and sediment-trap fluxes at the Time-series station KNOT in the northern North Pacific was found for over 4-year dataset. High correlations between Al flux and opal flux were observed. However, atmospheric cyclone and opal flux were also correlated well with 10-day time lag. It is important to determine the contribution to primary productivity of phytoplankton caused by sporadic meteorological events such as cyclone and typhoon as well as atmospheric input of iron to the open ocean regions.
15:15–15:30	Tea Break
15:30-15:55	Jerry Wiggert (Modeling Indian Ocean biogeochemistry: Iron limitation and dipole-zonal mode impacts) Jerry D. Wiggert, Center for Coastal Physical Oceanography, Old Dominion University, Norfolk, VA 23529 USA jwiggert@ccpo.odu.edu Keywords: Monsoon, Aeolian Dust, Marine ecosystem modeling, Physical-biological Interaction, Planetary Waves Results from a coupled, 3-D bio-physical ocean general circulation model will be presented that indicate: 1) the Indian Ocean (IO) exhibits pronounced spatial gradients and temporal variation in iron limitation patterns; 2) the Arabian Sea ecosystem is highly sensitive to the spatio-temporal distribution of aeolian iron deposition and; 3) inter-regional connections are critical driving mechanisms behind the seasonal to interannual variability in biogeochemical processes observed around the IO. These new insights into basinwide biogeochemical cycling have also been facilitated by comprehensive sampling oceanographic programs, in particular the Arabian Sea JGOFS activities of the 1990s, and the ongoing accumulation of physical and bio-optical data measured from remote sensing platforms. The spatio-temporal variation in nutrient limitation in the main climatological solution reflects the distribution of mineral dust sources around the IO and the contribution of upwelled waters with a higher N:Fe ratio. Sensitivity to aeolian deposition is revealed through the application of two separate mineral flux distributions, derived from the GISS and GOCART atmospheric transport models. With GOCART deposition, SW Monsoon phytoplankton blooms in the western and central Arabian Sea are enhanced and greater realism is exhibited. The central Arabian Sea bloom is supported by supplemental input of horizontally advected iron from a pool that undergoes a yearlong progression that originates in the Gulf of Oman, where the difference in aeolian iron enrichment between the two deposition fields is most prevalent. The GOCART-enhanced blooms entail a more pronounced shift toward netplankton and 20% higher export flux. Intermittent iron limitation in the Arabian Sea certainly challenges canonical thinking; yet this characterization is supported by recent observations. Moreover, this suggests that climate or land use influences on dust mobilization could exercise leading-order controls on regional biogeochemical variability, metabolic status and air-sea exchanges of CO2. The basin's primary inter-regional connections are associated with the semiannual Wyrtki Jet, westward propagating Rossby waves and northward flowing Somali Current. The normal linkages, and associated biogeochemical patterns, are significantly disrupted during manifestations of the IO Dipole or Zonal Mode (IODZM). To assess how these inter-regional connections impact ecosystem variability over the entire IO basin, EOF analyses of remote sensing observations are utilized in conjunction with results from climatologically and interannually forced numerical experiments. The climatological solution illustrates typical biogeochemical variability while the interannual solution provides insight into how basinwide biogeochemical processes are modified by IODZM manifestations. A composite IODZM for the three prominent events of the 1990s is developed that reveals a significant spatial reorganization of biogenic export. A 10% reduction in basinwide export from the euphotic zone is indicated, with the largest reductions (~20%) occurring in the western half of the equatorial and southern tropical regions. During the most prominent IODZM of the past four decades (1997/1998) these trends are notably magnified.
15:55-17:00	Convene first round of breakout sessions Working groups will be broken out and charged with summarizing the information that has been presented and specifically identifying prominent gaps in our understanding and making recommendations for future research and observations to fill these gaps: Potential working groups: Atmospheric processes and climate, physical variability and circulation, nutrient cycling, N2-fixation, Fe and trace metal cycling and limitation.
17:00-18:30	Poster presentations and refreshments
Evening	(Dinner on your own)
Day 2 (Wednesday 4th October)
8:30-9:20	Convener Guidance and Working Group Reports
Session 2. (contd)
9:20–10:45	Karl Banse (Day-to-day, seasonal, interannual, and interdecadal variability of oxygen and nitrite in the oxygen minimum zone of the central Arabian Sea) Karl Banse and James R. Postel, University of Washington, School of Oceanography, Seattle, WA, USA banse@ocean.washington.edu Key words: Arabian Sea, oxygen minimum, O2 changes, pycnocline ventilation In the Indian Ocean, the Arabian Sea (AS) deserves special biogeochemical interest because it contains the largest of the three open-sea oxygen minimum zones (OMZs), which appear to account for one-quarter to one-third of the marine denitrification. For the upper layers of the AS, Wiggert et al. (Prog. Oceanogr. 65:176-313, 2005) state that our general understanding of this ecosystem is constrained by insufficient understanding of coastal upwelling and of year-round variability associated with the mesoscale eddy field. We extend this sentiment to the layers in and below the permanent pycnocline (mesopelagial) which contain the OMZ. A. Together with S.W.A. Naqvi and his colleagues we study the temporal stability of O2 and NO2- in a broad meridional band (8-21oN, 64-68oE) of the OMZ between 1960 and 2005. Here, we focus on the hydrographic observations. 1. Between 12-13 and 15oN, from 150-200 to at least 500m depth, a hydrographic discontinuity suggests zonal movement south of this region. Hence, the oxygen advected from south of the equator does not directly enter the OMZ via our meridional band. Also, the sharp southern border of the OMZ at that latitude does not reflect a balance between supply and demand of O2, but is caused by water movements. 2. As already known, heat in the central AS is seasonally transported to about 200m or somewhat deeper, seemingly across isopycnals. North of the discontinuity under (1), from T-S diagrams we infer lively seasonal water movements along isopycnals between 300 and at least 500m depth. At fixed positions the north-south inclination of the isopycnals leads to seasonal temperature and salinity changes. Also, we observe a significant seasonal change of O2 that is too large to be caused merely by changes of vertical flux of POC. What is the circulation that maintains fairly constant inter-annual mean fields of hydrography and O2 in the face of marked seasonal rates of change? 3. On the decadal scale at the 200-500 m horizons, salinity is declining near 15oN (near Goa), but farther north, more often than not it is increasing. O2 between 15 and 18-20oN has been declining during all seasons since the 1960s, while high nitrite values (a sign of denitrification) have become more numerous. O2 seems to increase near 20oN. The reasons for these patterns are unclear. There is no correlation between salinity and O2. Who is going to study the mesopelagic zone toward budgets of salinity and oxygen? B. Independently, we find that the winter convection north of about 22oN apparently annually generates water with a sigma-t of roughly 25 kg m-3. Its subduction ventilates the top of the pycnocline such that the O2 content of water of 23-25oC, southward to about 20oN, is 1-2 mL L-1 higher than in the OMZ. It is unclear whether this water is upsloping on Pakistan’s shelf during the SW monsoon when the thermocline is often at 20-30 m depth.
9:45-10:10	Lou Codispoti (The NW Indian Ocean’s biogeochemistry in relation to a changing planet and changing concepts) L.A. Codispoti, University of Maryland Center for Environmental Science, Horn Point Laboratory, P.O. Box 775, Cambridge, MD 21613, USA codispot@hpl.umces.edu Key words: Arabian Sea, Oxygen Minimum, Nitrogen, Bay of Bengal As in other ocean basins, the Indian Ocean has a widespread Oxygen minimum zone (OMZ), but this OMZ is extremely well-developed in central portions of the Arabian Sea where oxygen concentrations become vanishingly small. Under these suboxic (O2 ~ 0-3 micromolar) conditions, changes in nitrogen cycling make the Arabian Sea a major site for the removal of fixed nitrogen from the ocean despite its relatively small size. At the boundaries of the suboxic zone, nitrous oxide production is greatly enhanced contributing to the role of the Arabian Sea as an important source for this gas. Enhanced phosphorite deposition is associated with these low oxygen waters, and the speciation of iodine and trace metals is altered. These extremely low oxygen concentrations also re-structure the ecosystem. For example, zooplankton concentrations are enhanced at the bottom boundary of the suboxic zone. Recent studies suggest that canonical estimates of fixed-nitrogen removal in the Arabian Sea's suboxic zone are too low and that this region may remove ~ 60 Tg of fixed-N/yr from the world ocean. The relative importance of canonical denitrification vs the "anammox" process in the removal of fixed-N is currently under debate, and we will update this debate in this presentation. While the Arabian Sea's suboxic zone shares some similarities with comparable sites in the Eastern Tropical Pacific and off SW Africa, it differs insofar as it is under the Monsoon Regime rather than eastern boundary dynamics. It is also, not as closely connected to coastal processes as are the other major sites of suboxic water. How might the Arabian Sea's OMZ change in response to changes in the Monsoon Regime? Conditions in portions of the Bay of Bengal's OMZ closely approach suboxia, and perhaps there are sporadic suboxic events and some removal of fixed-N. How sensitive, therefore, is the Bay of Bengal's OMZ to global change? Similarly, there appear to be sporadic suboxic events outside off the Arabian Peninsula and in the Gulf of Oman, outside of the canonical suboxic zone. Overall, one has the impression of a system that may be sensitive to change.
10:10–10:35	Rajesh Agnihotri (Past records of marine denitrification in the Arabian Past records of marine denitrification in the Arabian Sea, ETNP and ETSP: Implications for atmospheric N Sea, ETNP and ETSP: Implications for atmospheric N2O variability) Rajesh Agnihotri1 and Mark A. Altabet2 1 National Institute of Oceanography, Dona Paula Goa  403004, India ragnihotri@nio.org 2 School for Marine Science and Technology, University of Massachusetts Dartmouth, New Bedford, MA-2744, USA maltabet@umassd.edu Keywords:  Denitrification, N2O, Arabian Sea, ETSP/ Peru margin Denitrification is the major loss term for combined N in the global N cycle and is therefore crucial for controlling the oceanic inventory of N (Codispoti et al., 2001). Several studies from the Arabian Sea (AS) and equatorial north Pacific (ETNP) have established an intimate coupling between past variations in marine denitrification intensity and late-Quaternary climate changes on millennial time scales (Altabet et al., 1995, 2002; Ganeshram et al., 1995). In addition to influencing oceanic inventory of N, marine denitrification is also a significant natural source of N2O (a potent greenhouse gas capable of directly and indirectly influencing global climate) to atmosphere. Major marine upwelling centers such as AS, ETNP and equatorial south Pacific (ETSP)/ Peru margin are considered as ‘hot spots' of N2O emissions to the atmosphere. Recent studies in heavily human impacted coastal areas of the eastern Arabian Sea have indicated significantly increased N2O fluxes to atmosphere, most likely attributable to a plausible anthropogenic influence on marine denitrification in the modern era (Naqvi et al., 2000).
10:35–11:00	Tom Anderson (Modeling denitrification) Tom Anderson, University of Southampton, Southampton, UK tra@noc.soton.ac.uk A three dimensional hydrodynamic-ecosystem model was used to examine the factors determining the spatio-temporal distribution of denitrification in the Arabian Sea. The ecosystem model includes multiple currencies (N, C, O), cycling of organic matter via detritus and dissolved organic matter, and both remineralisation and denitrification as sinks for material exported below the euphotic zone. Model results successfully reproduced the seasonality in plankton dynamics and vertical profiles of nitrate. Predicted denitrification in the denitrification zone (north of 10ºN and east of 55ºE) was 26.2 Tg N yr-1, being greatest during the northeast monsoon when primary production is co-located with the main zone of anoxia. Detritus was the primary organic substrate consumed in denitrification (97%), with a small (3%) contribution by dissolved organic matter. Lateral advection of organic matter played only a minor role in fuelling denitrification. Analysis of the carbon budget indicated that the modeled vertical export flux of detritus, which corresponds well with thorium data, is sufficient to account for measurements of bacterial production made below the euphotic zone in the Arabian Sea.
11:00-11:15	Tea Break
Session 3. (Review of the state of our knowledge–Biological production and remineralization of organic matter) Presentations reviewing of the state of our knowledge of the IO basin as it relates to biological production, export flux variability and remineralization.
11:15-11:40	Jorge Sarmiento (The role of sub-Antarctic mode water in global biological production) J.L. Sarmiento1, J. Simeon, and A. Gnanadesikan 1Princeton University, AOS Program, Princeton, NJ USA jls@princeton.edu Previous studies have shown that Subantarctic Mode Water is the primary pathway by which nutrients that are lost to the deep ocean by organic matter export are returned to the main thermocline. In this presentation we discuss model simulations of how the SAMW nutrients are fed from the main thermocline into the surface ocean, there to drive biological production; and how SAMW responds to global warming in the NOAA GFDL CM2.1 coupled climate model.
11:40-12:05	Helga Gomes (Algal blooms in the Arabian Sea–Are they changing?) Helga do Rosario Gomes1, Joaquim I. Goes1, S.G. Prabhu Matondkar2, Sushma G. Parab2, Adnan R. N. Al-Azri3, Prasad G. Thoppil4 1Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, ME, 04575, USA; hgomes@bigelow.org 2National Institute of Oceanography, Dona Paula, Goa, 403004, India 3Dept. of Marine Science and Fisheries, Sultan Qaboos University, Al-Khod, 123,Oman 4Oceanography Department, Naval Postgraduate School, Monterey, CA, 93943, USA Until the late 1990s, Noctiluca miliaris Suriray (synonym Noctiluca scintillans Macartney), a large heterotrophic dinoflagellate was a minor component of phytoplankton population in the Arabian Sea, appearing in bloom form only sporadically in coastal regions predisposed to upwelling and deep slope water intrusions during the southwest monsoon. Since then however, Noctiluca blooms have increased in frequency and intensity, but with the majority of blooms being observed following the northeast monsoon season and at times, in association with the well known blooms of the diazotroph Trichodesmium sp. Microscopy and chemotaxonomy from HPLC analysis of phytoplankton pigments initiated in 2003 suggest that Noctiluca blooms are becoming more intense and widespread in the Arabian Sea. Large blooms of these organisms have also started appearing off the coast of Oman. This study uses the recently available merged SeaWiFS and MODIS/Aqua ocean color data to investigate the temporal evolution and spatial extent of these taxonomically validated blooms. Additionally Aqua-MODIS SST and sea surface height anomaly data are used to investigate the role of mesoscale eddies in the production and dispersal of these blooms in the western north Arabian Sea.
12:05-12:30	John Marra (The effects of vertical mixing on phytoplankton in Indian Ocean regions) John Marra, Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964, USA marra@ldeo.columbia.edu Keywords: JGOFS, chlorophyll-a, productivity, monsoon Temporal and spatial variations in phytoplankton biomass exist in the Arabian Sea at all scales from the diurnal to the seasonal, and from fine to large scale. Phytoplankton physiological rate parameters and productivity measurements suggest that phytoplankton are not limited by either irradiance or nutrient supply. Grazing activities, in most cases, match phytoplankton net photosynthetic rates and growth. The observed variations in biomass are explained on the basis of the effects of vertical mixing, for example, from upwelling near the Omani coast or associated with mesoscale eddies. Vertical mixing is never deep enough to limit phytoplankton productivity, and nitrogen does not appear to be a factor limiting phytoplankton growth. Vertical mixing, however, also affects grazing by diluting micro-grazers along with phytoplankton. It is argued here that mixed layer deepening acts as a natural ‘dilution experiment' which can allow phytoplankton to escape grazing losses and grow, and thereby create the observed variability in phytoplankton biomass.
12:30-12:55	Prasanna Kumar (What drives the biological productivity of the Bay of Bengal and Arabian Sea?)
12:55–14:00	Lunch
14:00-14:25	Rengaswamy Ramesh (Nitrogen assimilation and f-ratios in the Indian Ocean) Rengaswamy Ramesh1, Satya Prakash, Rohit Srivastava, Naveen Gandhi and Sanjeev Kumar 1Physical Research Laboratory, Ahmedabad, India; rramesh@prl.res.in Cycling of nitrogen plays an important role in our environment and ecosystem. Primary production by photosynthesis is directly related to the nitrogen cycle and the productivity of many ecosystems is known to be controlled by nitrogen availability. Here we focus on new and regenerated production measurements. New production has been defined as the part of primary production supported by external nitrogenous inputs of upwelled, riverine or eolian origin introduced in the photic zone, whereas regenerated production is defined as that part of the primary production which sustains on recycled nutrients like ammonia and urea, within the photic zone. Studies on new production in the Indian Ocean were limited to the north-western Arabian Sea1-2.Over the past four years we have extended such measurements to other parts of the Indian Ocean3-6. We measured the nitrogen uptake by phytoplanktons in various parts of the Indian Ocean, using the 15N tracer7-8. We have also measured the uptake during a bloom. In general, it appears that the ratio of new production to the total production (the ‘f-ratio') is higher in the Bay of Bengal than in the Arabian Sea except perhaps for the highly productive western Arabian Sea, and during blooms elsewhere in the Arabian Sea. We shall present a overview of nitrogen assimilation in the Indian ocean including new results form the equatorial and southern Indian Oceans.
14:25-14:50	Mike Landry (Zooplankton grazing and secondary production in the Indian Ocean) Michael R. Landry, Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA mlandry@ucsd.edu Zooplankton grazing and secondary production define the net interactions of complex assemblages of planktonic consumers with higher and lower trophic levels. The primary fate of phytoplankton in the oceans is largely determined by grazing, which is globally dominated by the microzooplankton. Micro-herbivores also dominate as secondary producers; however, the production of trophically diverse meso- and macrozooplankton is generally more relevant as a flux constraint to higher-level predators. This presentation will synthesize present knowledge of the conceptual relationships, measurement complexities and general magnitudes of grazing and production processes in the Indian Ocean, and how they vary with community structure and system variability.
14:50–15:15	Sharon Smith (Mesozooplankton dynamics and ecosystem impacts) Sharon L. Smith The Rosenstiel School University of Miami 4600 Rickenbacker Causeway Key Biscayne, FL 33149 sharon.smith@rsmas.miami.edu Key Words: upwelling, mesozooplankton, diatoms, carbon flux, climate change A combination of model results, paleoclimate records, and correlations among present-day monsoon variables all fit together into a consistent paradigm suggesting that we can predict the outcome of global warming in the Arabian Sea region. Because warming would reduce snow and ice cover on the Tibetan Plateau, 1) the pressure gradient between the plateau and the surrounding ocean would be increased, 2) the SW Monsoon winds would increase, and 3) upwelling would become both more vigorous and more widespread. Increased upwelling is also associated with increased deposition at the seadbed, a projection based upon observations from the last interglacial period (~9000 years B.P.). During the last glacial period, 18,000 years B.P., the SW Monsoon was weak (or nonexistent), and diatoms were absent in the sediments. Since global warming is expected to continue to accelerate, the ocean ecosystem of the Arabian Sea should experience increased upwelling, a condition favorable to proliferation of diatoms and the copepods C. carinatus and S. crassus. Present-day onset of coastal upwelling off the Arabian Peninsula presents persistent physical and chemical conditions which should support a high biomass bloom of diatoms (sufficient nutrients, stability, seed populations, iron, physiological readiness); however, no diatom bloom occurs. It is possible that diapausing copepods in the water to be upwelled prevent a bloom from developing during the early and middle SW Monsoon by their predation upon the diatoms. These conditions are in stark contrast with other upwelling areas where diatom growth and zooplankton feeding are uncoupled at the onset of upwelling, and at the boundaries of the upweling area, leading to massive diatom blooms which support large clupeid fisheries within tens of kilometers of the coast.
15:15-15:30	Tea Break
15:30-15:55	Ramaiah Nagappa (Bacterioplankton abundance and production in different regions of the Indian Ocean) Nagappa Ramaiah, National Institute of Oceanography, Dona Paula, Goa 403 004, India ramaiah@nio.org Beginning from the 1970s, there have been unprecedented discoveries related to marine microbial ecology. Information on microbial abundance, distribution, production, involvement in nutrient cycling and how microbes are at the base of microbial food web has helped in realizing their importance in marine biogeochemistry. Decomposition of complex organic molecules, respiration, mineralization, uptake of dissolved organic compounds and their conversion to particulate matter are largely due to growth and activity of heterotrophic bacteria. Thus, the ubiquitous and self-regulating microbial communities are pivotal, for instance, in marine food-web dynamics. A comparative account of bacterial abundance and production rates measured from the biologically highly productive Arabian Sea and the less productive Bay of Bengal and oligotrophic equatorial Indian Ocean is now available. Investigations under the aegis of JGOFS and Bay of Bengal Process Study have brought to light that physical and chemical processes that govern the primary production are quite contrasting in the former two basins. In the highly productive Arabian Sea: a) heterotrophic bacteria are pivotal in the rapid recycling of organic matter in the shallower (~50-55m) euphotic zone; b) there is decoupling between primary production and bacterial abundance; c) their production sometimes exceeds primary production; d) they are sustaining microbial loop during lean phytoplankton-production seasons and, e) there is net heterotrophy, at least seasonally.
15:55–17:00	Convene second round of breakout sessions Working groups will be broken out and charged with summarizing the information that has been presented and specifically identifying prominent gaps in our understanding and making recommendations for future research and observations to fill these gaps. Potential working groups: denitrification and OMZ processes, chlorophyll and primary production, zooplankton and secondary production, bacteria and microbial ecology.
17:00-18:30	Poster presentations and refreshments
Evening	(Dinner on your own)
Day 3 (Thursday 5th October)
8:30-9:20	Convener Guidance and Working Group Reports
Session 3. (contd)
9:20-9:45	Farooq Azam (Microbial Ecology) Farooq Azam, Scripps Institution of Oceanography, University of California, San DiegoLa Jolla, CA 92093 USA fazam@ucsd.edu Exciting discoveries in microbial oceanography during the last three decades have shown that highly diverse microbes play critical roles in regulating the biogeochemical state of the ocean. Understanding their biogeochemical function is necessary in order to prognosticate the response of marine ecosystems to stresses e.g. global change, pollution, over-fishing and intensive mariculture. The microbes’ response to stress may not only affect oceanic biogeochemistry but also human health, e.g. via proliferation of existing and emergence of new microbial pathogens. Thus, marine microbes should be considered a significant biological force affecting global habitability. However, their great diversity, diminutive size and metabolic plasticity conspire to make it fiendishly difficult to integrate microbial processes into models of ecosystem function. Microbes structure marine ecosystems at the microscale, so the challenge is to integrate their biogeochemical activities across vast spatial scales, from micrometers to ocean-basins. I will argue that understanding the biochemical and molecular interactions of microbes with their microscale environments is essential as basis to integrate their biogeochemical activities into models of the ocean’s response to global change.
9:45–10:10	Bess Ward (Diversity and Dynamics of Denitrifying Bacteria in the Arabian Sea from Analysis of Nitrite Reductase Genes) Bess B. Ward1 and Amal Jayakumar 1 Department of Geosciences, Princeton University, Princeton, NJ 08544 bbw@princeton.edu Key Words: Denitrification, microbial bloom dynamics, nirS In an effort understand the environmental variables that control denitrification, we have performed incubation experiments and investigated the composition of denitrifying bacterial assemblages in the oxygen deficient waters of the Arabian Sea, ETNP and ETSP. Seawater from the oxygen deficient zone (ODZ) was incubated in trace-metal clean gas impermeable 10-L bags to investigate community response to metal, chelator, and carbon additions. Denitrification was not limited by trace metal availability (Cu, Fe) at any of the sites, but was carbon limited in the ETNP and ETSP. In the absence of carbon limitation, denitrification proceeded in the incubations through the sequential depletion of nitrate, and the transient accumulation and depletion of nitrite, and was accompanied by cell growth. Copper limitation could be induced by the addition of specific chelators, in which case N2O accumulated transiently. Denitrifier community composition in the Arabian Sea ODZ was evaluated using sequence and T-RFLP analysis of key denitrification genes in clone libraries from several stations as well as from the bag incubations. Early in the denitrification sequence, denitrifier diversity was very high, even though nirS and nirK genes cannot always be detected before denitrification begins. As denitrification progresses, denitrifier diversity decreases, so that by the time all oxidized N is exhausted, the assemblage is dominated by one or a few operational taxonomic units (OTUs). This occurs in time series of denitrification development in large incubation bags, in coastal and oceanic water where the stages of denitrification are identified in space, rather than in time, and for both nirS and nirK genes. These bloom dynamics indicate that species composition is likely to be an important determinant of denitrification rates. The emergence of dominance from the background diverse assemblage has implications for regulation of the process, and for the maintenance of overall diversity in the functional guilds of denitrifiers. Although the total denitrifier diversity of both coastal and oceanic environments is high, most denitrification appears to occur when the community has shifted towards dominance of a few types.
10:10–10:35	Joe Montoya (Nitrogen Isotopes and Particle Dynamics) Joseph P. Montoya1 and Maren Voss2 1 School of Biology, EST Building, 311 Ferst Drive, Atlanta GA 30332 USA, montoya@gatech.edu 2 Institüt Für Ostseeforschung, Seestrasse 15, 18119 Warnemünde, GERMANY, maren.voss@io-warnemuende.de Keywords: Nitrogen cycle, Nitrogen isotopes, denitrification, Nitrogen fixation, Suspended particles Nitrogen stable isotopes provide a natural, in situ record of the N-cycle processes at work in marine ecosystems.  Within the oxygen minimum zone of the Arabian Sea, denitrification results in an increase in the 15N content of the residual nitrate (Brandes, Devol et al. 1998), which in turn contributes to a generally high 15N abundance in suspended particles (Montoya and Voss 2006).  Samples collected during the German JGOFS expedition to the Arabian Sea in May-June 1995 showed the expected enrichment in 15N in suspended particles, but with surprisingly little variation in 15N abundance below the surface mixed layer.  This pattern suggests that the isotopic imprint of particles within the oxygen minimum zone (OMZ) is driven primarily by processes acting above or at the upper margin of the OMZ.  The isotopic imprint of denitrification extended well beyond the oxygen minimum zone proper and was detectable as far south as the equator (Montoya and Voss 2006).  Interestingly, the surface waters of the Arabian Sea seasonally support large populations of N2 fixing cyanobacteria (Capone, Subramanian et al. 1998), making this one of the few oceanic regions in which both denitrification and N2 fixation are known to occur together.  N2 fixation introduces 15N-depleted nitrogen to the ecosystem, resulting in a clear isotopic contrast between the surface mixed layer and the OMZ (Montoya and Voss 2006).  The isotopic signature of N2 fixation  propagates into the OMZ via sinking particles, but the uniform 15N composition of particles at depth as well as the vertical pattern of 15N enrichment in sinking particles both suggest that denitrification is the dominant process determining the isotopic composition of suspended particles in the Arabian Sea OMZ.
10:35-11:00	Maren Voss (N-cycle investigation in the Arabian Sea by means of stable nitrogen isotopes) Maren Voss1 and Joe Montoya2 1 Institüt Für Ostseeforschung, Seestrasse 15, 18119 Warnemünde, GERMANY, maren.voss@io-warnemuende.de 2 School of Biology, EST Building, 311 Ferst Drive, Atlanta GA 30332 USA, montoya@gatech.edu Nitrogen is a limiting element for primary production in the oceans. Its major source to the open ocean is nitrogen fixation by diazotrophs having d 15N values slightly below zero. The remineralisation of this biomass leads to isotopically light nitrate. On the other hand nitrate has high d15N values when it is removed by denitrification. On geological time scales these processes are supposed establish a d15N signal of 4-5%o for oceanic nitrate. Deviations towards higher values have been found in OMZs of the Arabian Sea and the Pacific where denitrification was active and lower ones are found in tropical regions with high fixation activity.To investigate the processes generating the signature (nitrate uptake by photoautotrophs, nitrification during remineralisation, denitrification) it may help to measure the oxygen isotopes in nitrate as well. The same fractionation for 18O and 15N exists for both denitrification and NO3 assimilation, but the ratio of N:O fractionation may change according to environmental factors and rates of processes. This may be especially interesting to study in the Arabian Sea where all ammonium from regeneration of organic matter is oxidized to nitrate. The isotope signature of the nitrogen should then be the same in nitrate and PON, while the oxygen values depend on additional factors. Nitrate samples from
11:00-11:15	Tea Break
11:15-11:40	Alan Devol (Excess nitrogen gas in oxygen deficient zones) A.H. Devol, University of Washington, Seattle, WA USA; devol@u.washington.edu B.X. Chang, University of Washington, Seattle, WA USA S.W.A Naqvi, NIO, Goa, India Nearly all water-column denitrification rate estimates are based upon nitrate disappearance alone, which is mostly determined from N-P stoichiometry. Indeed, only a few measurements of the excess of nitrogen gas produced by denitrification have been made. Here we report measurements of nitrogen gas concentrations in waters from the Arabian Sea and Peru upwelling system along with denitrification rate measurements made by 15NO3 incubations. Nitrogen gas measurements are presented as normalized nitrogen:argon ratios, (N2:Ar)n=(N2:Ar)s /(N2:Ar)e [where (N2:Ar)s is the sample ratio and (N2:Ar)e is the atmospheric equilibrium ratio, such that at equilibrium (N2:Ar)n=1.00]. Profiles from outside the denitrification zone of the Arabian are similar to profiles from other oxygenated waters of the Atlantic, Pacific and Southern Ocean, while within the oxygen deficient zones, there is a distinct maximum in the (N2:Ar)n showing the excess of nitrogen gas over saturation values resulting from denitrification. The fractional excesses were multiplied by the equilibrium saturation gives the actual concentrations of excess nitrogen. Within both the denitrification zone, there was a distinct peak of excess nitrogen in the oxygen deficient zon.. Comparison of the nitrogen gas excess with nitrate deficits resulted in excess nitrogen being about twice as great nitrate deficit in the Arabian Sea while nitrogen excess was about equal to nitrate deficit off Peru.
11:40–12:05	Tim Rixen (Monsoonal and ENSO impacts on the biological pump in the Indian Ocean) T. Rixen1, V. Ittekkot1, M.V.S. Guptha2, Bambang Herunadi3, and E. Maier-Reimer4 1 Zentrum für Marine Tropenokologie (ZMT), Fahrenheitstr. 6, 28359 Bremen, Germany; trixen@uni-bremen.de 2 National Institute of Oceanography, Dona Paula, 403802 Goa, India 3 Agency for the Assessment and Application of Technology (BPPT), Jakarta, Indonesia. 4 Max Planck Institute for Meteorology, Hamburg, Germany. Sediment trap experiments have been carried out at water-depth > 1000 m in order to study factors influencing the CO2 uptake of the biological pump in the Indian Ocean. Satellite-derived observations on upper ocean parameters, model results and data obtained during the Joint Global Ocean Flux Study (JGOFS) have additionally been used to link sediment trap records to surface ocean processes. The results imply that diatom blooms favored by upwelling-driven and riverine silica inputs into the euphotic can enhance the biological mediate CO2-uptake in the northern Indian Ocean which generally acts as CO2 source. Organic to carbonate carbon (rain) ratios which are higher in river-influenced than in upwelling-driven systems suggest that freshwater inputs further enhance the CO2 uptake of the biological pump. This seems to be caused by riverine nutrient inputs increasing the photosynthesis of organic matter and the low calcite saturation state of freshwater reducing the carbonate precipitation. Furthermore, freshwater inputs form a buoyant low salinity surface layer that caps off the nutrient and CO2-rich subsurface waters. An enhanced capping-effect during wetter La Niña conditions decreases the CO2 emission into the atmosphere along the freshwater influenced continental margins in SE Asia as shown by our model results. By contrast enhanced CO2 emissions from the Asian freshwater influenced continental margins seems to counteract reduced CO2 mission from the upwelling area in the equatorial Pacific and contributes to elevated atmospheric CO2 levels observed during El Niño events.
12:05–12:30	Man Mohan Sarin (Spatial and temporal scale 234Th:238U disequilibrium in the Arabian Sea: Implications to sinking particle fluxes) Sarin, M.M., Physical Research Laboratory, Ahmedabad 380 009, India sarin@prl.res.in  234Th (t1/2 = 24.1d) - based method is perhaps the "single best" method for studying the rates of particle-associated chemical scavenging processes, particle transformation and settling fluxes in the upper ocean on time-scales from less than a week to one month or more. In essence, the 234Th-238U radioactive disequilibrium in the surface ocean is a reflection of the 234Th flux on settling particles to deep layers. Another usefulness of 234Th is seen as a potential tool for assessing the in-situ collection efficiency of the sediment traps by comparing its flux from the surface ocean with that collected by a trap positioned at a desired depth (100-300 m). The long-term measurements made on the vertical profiles in the Arabian Sea and Bay of Bengal reveal close similarity in the 234Th-238U disequilibrium suggesting that the rates of particle scavenging processes are of similar magnitude on a basin-wide scale. The observed disequilibria, integrated for the upper 100m, yield a mean removal residence time of 40-60 days for the dissolved Th with respect to particle uptake and vertical export. The water-column derived 234Th export fluxes in the Arabian Sea exhibit southward decreasing trend during the late NE-monsoon (February-March : 2300-1250 dpm m-2 d-1) and inter-monsoon (April-May : 1685-1345 dpm m-2 d-1); whereas the export fluxes are of comparable magnitude during the summer monsoon (July-August ~ 2200 dpm m-2 d-1).
Session 4. (Review the state of our knowledge – Pelagic carbon cycling and air-sea exchange) Presentations that will provide a review of the state of our knowledge of the IO basin as it relates to carbon cycling and CO2 exchange.
12:30–12:55	Dennis Hansell (Dissolved organic matter and the carbon cycle – Arabian Sea and Indian Ocean) D.A. Hansell, University of Miami, RSMAS, Miami, FL USA dhansell@rsmas.miami.edu Concentrations of dissolved organic matter have been determined in relatively few locations and times in the Indian Ocean. Here I review the work in which my laboratory participated. For example, the US JGOFS Arabian Sea project conducted analyses with good seasonal coverage for one year (1995) in the western and central Arabian Sea. The US occupation of WOCE section I8 (80?E) between September and October of 1995 resulted in spatial distribution data from the central Indian Ocean. Given this coverage, we have only a weak knowledge of the spatial distributions, but a better knowledge of temporal variability for the western Arabian Sea. This presentation reviews our understanding for DOM in the Indian Ocean, from the deepest layers (in the context of the global distribution of deep ocean DOM) to seasonal variability and biological transformations in the upper layer (considering the role of DOM as a reservoir for major elements). Issues to be addressed with future work in the region includes the role of margin/open ocean exchanges and the contributions of eddies to ocean productivity and biogeochemistry.
12:55-14:00	Lunch
14:00 – 14:25	Daniela Unger (Some aspects of the biogeochemistry of organic matter in the northern Indian Ocean) Daniela Unger, Center For Tropical Marine Ecology, Fahrenheitstrasse 6 D-28359 Bremen, Germany daniela.unger@zmt-bremen.de Despite common features (i.e. monsoon-driven reversal of ocean surface circulation, extended oxygen minimum layer) the eastern and western basin of the Northern Indian Ocean, the Bay of Bengal (BoB) and the Arabian Sea (AS), reveal significant environmental differences which affect organic matter biogeochemistry. The unique feature of the BoB is the enormous riverine input associated with monsoonal rainfall resulting in a strong freshwater-related stratification of the surface layer. This stratification is considered one reason for the reduced productivity in the Bay as compared to the Arabian Sea. On the other side, rivers deliver about 1.4 Gt of particulate matter (AS: 0.2 Gt). This input outweighs the reduced productivity and leads to particle flux rates comparable to the AS and also influences organic matter decay. The quality of organic matter in the BoB is described using content and composition of amino acids and carbohydrates as well as stable carbon and nitrogen isotopes. Literature data is used to compare organic matter composition from the Bay to riverine and terrestrial endmembers and to the conditions encountered in the Arabian Sea. Riverine material, which is characterized by its refractory nature, can be discerned but does not exert major control on bulk organic matter quality in the BoB. N isotope ratios, however, are low relative to the AS and mirror the lack of denitrification as well as riverine input and/or N-fixation.
14:25-14:50	Chris Sabine (Inorganic Carbon Distributions and Air-Sea CO2 Exchange in the Indian Ocean) C.L. Sabine and R.A. Feely, Pacific Marine Environmental Laboratory, NOAA, Seattle, Washington, USA, chris.sabine@noaa.gov; F.J. Millero, Rosenstiel School of Marine and Atmospheric Science, University of Miami, FL, USA; C. Goyet, Universite de Perpignan, Perpignan, France; N. Bates, Bermuda Biological Station For Research, Inc., Ferry Reach, Bermuda; R.M. Key, Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, New Jersey, USA Keywords: Indian Ocean; carbon dioxide; water column; air-sea flux; biogeochemistry In the mid 1990s, several global carbon measurement programs focused on the Indian Ocean, greatly increasing the existing carbon database for this basin. This study examines the combined inorganic carbon measurements from three major U.S. programs in the Indian Ocean: the global carbon survey cruises, conducted in conjunction with the World Ocean Circulation Experiment (WOCE), the NOAA Ocean-Atmosphere Carbon Exchange Study (OACES) Indian Ocean survey and the Joint Global Ocean Flux Study (JGOFS) Arabian Sea Process Study. In particular, we focus on the distributions, controls, and exchanges of inorganic carbon in the Indian Ocean. Total alkalinity (TA) distribu­tions in the ocean are primarily controlled by circulation and the production/remineralization of calcium carbonate. The morphology of the Indian Ocean, with a northern boundary in the tropics, generates a circulation system that is unique to this ocean and thus TA distributions and carbonate dissolution patterns that are unique to this basin. Calcite and aragonite saturation depths shoal dramatically towards the north in the tropical Indian Ocean with evidence of significant dissolution both in the upper water column as well as from sediments. Dissolved Inorganic Carbon (DIC) is strongly influenced by the biological pump and air-sea gas exchange. The patterns of net community production diagnosed from DIC variations clearly show that monthly variations in biology and carbon chemistry are closely tied to the monsoon system. The uptake of anthropogenic CO2 has increased the shallow DIC by as much as 3%, decreasing the vertical DIC gradient. The Indian Ocean is a small net sink for atmospheric CO2 despite the fact that portions of the basin are perpetual sources of CO2 to the atmosphere and the region off the Oman coast can have some of the largest outgassing of CO2 per unit area observed in the open ocean. The Arabian Sea outgassing is counterbalanced by strong seasonal CO2 uptake in the Southern Indian Ocean. This study will review our current understanding of the controls on the distribution of TA, DIC and CO2 partial pressure in the Indian Ocean and how the relationship between these parameters defines the inorganic carbon system of the oceans and determines how the ocean carbon cycle will respond to changes in atmospheric CO2 and climate change.
14:50-15:15	Catherine Goyet (Anthropogenic CO2 in the Indian Ocean) Touratier F., Azouzi L. and C. Goyet, Université de Perpignan, 52 avenue Paul Alduy, 66860 Perpignan, France cgoyet@univ-perp.fr We used data from the WOCE Indian Ocean Cruises to provide estimates of anthropogenic CO2 concentrations in the Indian Ocean. Since anthropogenic CO2 concentrations in the ocean cannot be measured, it is very difficult to assess the accuracy of the various estimates. We used three measured anthropogenic tracers (CFC-11, ?14C, and 3H) to assess the relevance of the various estimates of anthropogenic CO2 distributions based upon very different hypotheses. The results of correlations of anthropogenic CO2 concentrations with the anthropogenic tracers 3H, CFC-11, and D14C, indicate that some approaches are likely to be more reliable than others. As a result, we gain some insights on the processes of anthropogenic CO2 penetration in the ocean. This study contributes to enhance and clarify our understanding of the present distribution of anthropogenic carbon in the Ocean.
15:15-15:30	Tea Break
15:30–15:55	V.V.S.S. Sarma (Net Community Production in the northern Indian Ocean)
Session 5. (Review the state of our knowledge – Impact of climate and human activities on biogeochemistry and ecosystems)
15:55-17:00	Convene third round of breakout sessions Working groups will be broken out and charged with summarizing the information that has been presented and specifically identifying prominent gaps in our understanding and making recommendations for future research and observations to fill these gaps. Potential working groups: export and remineralization variability and controlling processes, carbon cycling and air-sea exchange, and impact of climate and human activities on the IO.
17:00-18:30	Poster presentations and refreshments
19:00-20:00	Cultural Program (NIO Auditorium)
20:00-22:00	Dinner to be hosted by Director NIO
Day 4 (Friday 6th October)
8:30-9:20	Convener Guidance and Working Group Reports
Session 5. (contd)
9:20-9:45	Joaquim Goes (Changing productivity in the Arabian Sea linked to shrinking snow caps–How satellites helped connect the dots) Joaquim I. Goes1†, Prasad G. Thoppil2, Helga do R Gomes1, S. G. P. Matondkar3, Adnan R. N. Al-Azri4 and C. Coit5 1Bigelow Laboratory for Ocean Sciences, West Boothbay Harbor, ME, 04575, USA, jgoes@bigelow.org 2Oceanography Department, Naval Postgraduate School, Monterey, CA, 93943, USA 3National Institute of Oceanography, Dona Paula, Goa, 403004 India 4Dept. of Marine Science and Fisheries, Sultan Qaboos University, Al-Khod, 123,Oman 5Colby College, Waterville, Maine, 04901, USA The mid-latitudinal continental warming trend in the Northern Hemisphere and the progressive decline in winter and spring snow cover over the Eurasian continent, in particular over southwest Asia and the Himalayan/Tibetan region since the mid-1990s, is causing a land-ocean thermal gradient that is particularly favorable to stronger southwest (summer) monsoonal sea surface winds. Since 1997, sea surface winds have been strengthening in the western Arabian Sea. This escalation in the intensity of winds has brought about an intensification of coastal upwelling, leading to a profound increase in average summer time chlorophyll a concentrations off the coast of Somalia. Offshore over a wider region in the western Arabian Sea also, chlorophyll concentrations have been on the rise due to increased advection of newly-upwelled, nutrient-rich water away from the coast into the central Arabian Sea by wind-generated coastal filaments and jets. The extraordinarily large increase in chlorophyll in the western Arabian Sea has raised the intriguing possibility that the current warming trend of the Eurasian landmass is making the Arabian Sea more productive. The consequences of the climatic warming trend and changes in phytoplankton productivity on carbon cycling, biogeochemical processes and fisheries in the Arabian Sea, will be discussed in the light of these findings.
9:45–10:10	Wajih Naqvi (Seasonal Anoxia over the Western Indian Continental Shelf) S.W.A. Naqvi, Hema Naik, A.K. Pratihary, Witty D'Souza, Gayatree Narvenkar, D.A. Jayakumar, M.S. Shailaja, and P.V. Narvekar National Institute of Oceanography, Dona Paula, Goa 403 004, India naqvi@nio.org Keywords: Arabian Sea, Indian shelf, upwelling, anoxia, nitrogen cycle, denitrification, nitrous oxide, remineralization ratios The North Indian Ocean contains about two-third of the global continental-margin area affected by natural oxygen deficiency (O2 < 0.2 mL L-1) in the water column. Also, the littoral countries of this semi-enclosed basin account for a quarter of the world's population, making the sensitive O2-depleted environment especially vulnerable to anthropogenic perturbations. We describe here factors responsible for the occurrence of O2 deficient conditions, their evolution over the annual cycle, and their impact on biology and chemistry off the west coast of India. The O22-1), a very substantial fraction of the nitrate undergoing reduction appears to end up as nitrous oxide, which accumulates to levels rarely seen elsewhere in the ocean. Relative changes in dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) closely conform to those predicted by the Redfield-Ketchum-Richards stoichiometry in the oxic and suboxic waters. However, a higher-than-expected buildup of DIP occurs in anoxic waters, probably due to dissolution of the iron-oxyhydroxo-phosphate complex from sediments. This DIP may support nitrogen fixation after the cessation of upwelling. deficiency in this region, associated with the seasonal (southwest monsoon) upwelling, seems to have intensified in recent years, presumably in response to enhanced nitrogen loading from land. The O deficiency affects patterns of organic production and distribution of organisms including commercially important fishes, and modifies chemical fluxes through microbial reduction of polyvalent elements especially nitrogen (denitrification).
10:10-10:35	Sybil Seitzinger (River Nutrient Transport from Watersheds to Indian Ocean Coastal Systems: Amount, Forms and Sources) Seitzinger, S.P., Rutgers University, New Brunswick NJ, USA, sybil@marine.rutgers.edu; Dumont, E., and Kroeze, C., Wageningen University, Wageningen, Netherlands; Harrison, J.H., UC Davis, Davis, CA; Bouwman, A.F. and Beusen, A.H.W, Netherlands Environmental Assessment Agency, Bilthoven, The Netherlands Keywords: nutrients, rivers, watershed, land-use Rivers are the major transport pathway for transfer of nutrients (e.g., N, P, C) from land to coastal marine systems. Land-use in many watersheds of the Indian Ocean basin has been markedly altered due to the production and consumption of food and energy to support the human population in this region. As a result, river transport of nutrients from many of these watersheds to coastal waters of the Indian Ocean has changed in magnitude, form, and spatial pattern. Global models of Nutrient Export from WaterSheds (Global NEWS) were recently developed that relate land-use, human population, atmospheric deposition, and natural processes in watersheds to river transport of N, P and C (DIN, DIP; dissolved organic and particulate N, P, C) (published in a special section of Global Biogeochemical Cycles 19(4): Dumont et al. 2005; Harrison et al. 2005 a and b; Beusen et al. 2005; Seitzinger et al. 2005). Here we use these models to explore the spatial distribution, amount, form and sources of river transported, land-based nutrient inputs to the coastal waters of the Indian Ocean. According to NEWS model predictions, there is considerable spatial variation in the magnitude of river nutrient export, as well as in the major sources driving that export for rivers discharging to the coastal regions of the Indian Ocean. For example, river export of DIN ranges from less than 10 to over 2000 kg DIN /km2 watershed/yr. River export of DIP ranges from less than 0.5 to over 50 kg DIP/km2 watershed/yr. Fertilizer is the dominant source of DIN export for many rivers in India, although biological N2-fixation is the dominant source in many watersheds in southeastern Asia that drain into the Bay of Bengal. In contrast, for DIP export, sewage is the single largest contributor to DIP export from many basins in India, although natural sources (weathering) dominate DIP export from southeastern Asian watersheds. Comparisons of the spatial distribution and sources of dissolved organic and particulate N, P, and C will also be discussed.
Session 6. (Review the state of our knowledge – Benthic biogeochemistry and ecology)
10:35-11:00	Greg Cowie (Benthic cycling and fluxes) Greg Cowie, The Grant Institute, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, UK glcowie@glg.ed.ac.uk Keywords: Benthic, biogeochemistry, fauna, flux, cycle Biogeochemical processes and fluxes occurring across the sediment-water interface are important controls on geochemical cycles and ocean inventories of both bioelements and metals, and, through benthic-pelagic coupling, on ocean productivity and global climate. Benthic organisms, from microbes to megafauna, are intimately involved in these processes and fluxes, through feeding, bioturbation and irrigation (etc.). Yet, benthic processes generally remain poorly characterised or quantified by comparison with pelagic counterparts, and details on the roles of benthic communities are particularly unclear. Also, benthic processes in the Indian Ocean have received comparatively little study, despite it being home to remarkable regions such as the Arabian Sea and Bay of Bengal. These particular regions are disproportionately important due to a combination of unusual phenomena, including intense monsoon-driven productivity, massive sediment deposition, and the presence of the world's largest expanse of oxygen-depleted waters.  The result is dramatic cross-margin differences benthic redox conditions, sediment characteristics and faunal communities, as well as strong seasonal changes in productivity (and thus in food supply to the sea floor). Consequently, these regions represent natural laboratories for investigations of the roles of benthic communities in sea-floor biogeochemistry, where the processes concerned are of far-reaching significance.     A recently completed project involved an international team of ecologists and geochemists, and was focused on closely linked surveys of benthic communities and sediment geochemistry across the Pakistan (Indus) margin of the Arabian Sea. These surveys were combined with in situ and shipboard assessments of benthic process rates and biogeochemical fluxes, as well as pulse-chase tracer studies of benthic community function. The studies were carried out during four research cruises, at sites spanning (140m to 1850m) the oxygen minimum zone and during the intermonsoon (March-May) and late-to-post monsoon (August-October) periods, thus representing dramatic differences in benthic redox conditions and communities as well as seasonal differences in food supply. An overview of the project and selected research highlights will be presented, along with suggested topics for future research on benthic biogeochemistry in the Arabian Sea and Bay of Bengal.
11:00-11:15	Tea Break
11:15-11:40	Baban Ingole (Pattern of macrobenthic diversity along the eastern margin of the Arabian Sea) Baban Ingole, National Instituted of Oceanography, Dona Paula, Goa-403004, India baban@nio.org Keywords: Macrobenthos; Diversity pattern; Seasonality; OMZ; Arabian Sea One of the pressing issues in current ecology is the relationship between biodiversity and ecosystem functioning. The eastern Arabian Sea is of particular interest in this context; as this is one of the largest coastal areas where the sea floor is exposed to permanent, severe oxygen depletion commonly referred to as the oxygen minimum zone (OMZ). A distinct feature of the OMZ is the strong reduction in species diversity: The sediment dwelling communities play a major role in oceanic carbon cycling as they ultimately determine the fate of the organic carbon escaping water column degradation. Considering the limited information available on the benthic biology of the Arabian Sea, a three years study was conducted across the eastern margin between 20-100m water depths. The study was aimed at understanding the seasonal variability in diversity, abundance and biomass of metazoan macrofauna (>0.5mm size). Though the salinity did not show much seasonal variation, values for dissolved oxygen in bottom water indicated spatial as well as temporal variation. Also the values for chlorophyll content in sediment showed high variation (45.2-537.6 µg/g) between the seasons. The organic content in the sediment varied between 0.2-2.6%. Total 142 macrobenthic species belonging to 07 phyla were identified from 101 samples collected from nine stations. Benthic organisms were unevenly distributed and exhibited strong temporal variation. The highest number of species (112), faunal density (15829 no.m-2) and biomass (16.6g.m-2 wet wt.) were observed in post monsoon season. Highest faunal abundance was in the coastal stations located in 25-30 m water depth. Polychaeta was the dominant group in terms of species diversity and Prinospio pinnata; P. krusadensis; Prinospio. sp.; Ancistrosyllis constricta; Thyryx sp. were the most dominant species comprising »40% of the total faunal density. There was overall an increase in faunal abundance when compared to published data, mainly due to the dominance of opportunistic annelid species. However, benthic biomass did not show notable change. The overall dominance of polychaetes in OMZ area indicates their ability to exploit organically rich but unfavorable conditions. The area displayed a marked seasonality in the biological productivity; dissolved oxygen and sediment organic carbon. Thus, availability of food and dissolved oxygen in bottom water are the limiting factors for dominance of r-selection species, which regulate the benthic abundance and perhaps the demersal fishery of the area.
Session 7. (Future plans and technologies) Presentations reviewing the current status of the CLIVAR/GOOS IO observing system and plans for making use of several different types of observational platforms, including satellite remote sensing, moored sensors, survey cruises and ship-of-opportunity measurements.
11:40-12:05	Gary Meyers (Observation program for role of the Indian Ocean in the climate system) Gary Meyers, GPO Box 1538, CSIRO Marine and Atmospheric Research, Hobart TAS 7001, Australia Gary.Meyers@csiro.au Key words: cimate-modes, oceanic processes, observing system The CLIVAR/GOOS Indian Ocean Panel was established in 2003 and charged with preparing an implementation plan for sustained observations to support research and societal applications. The plan for the Indian Ocean Observing system (IndOOS) is published now and is available on the internet at http://eprints.soton.ac.uk/20357/01/IOP_Impl_Plan.pdf. This talk will firstly review the scientific rationale for sustained observations from the perspective of research on the physical role of the ocean in the climate system. Secondly, we'll present a sampling strategy that makes use of a variety of instruments. The science drivers are improved description, understanding, modelling and ability to predict the physical structure of the Indian Ocean in the monsoons and intra-seasonal variations, the Indian Ocean zonal dipole including interactions with ENSO, decadal variation and multi-decadal warming trends. The Indian Ocean has a unique system of major currents that affect the above climate-modes but that have not as yet been systematically observed. Our present day knowledge of some of the most important ocean-atmosphere interactions in these modes will be briefly reviewed. Implementation of the observing system will make use of all the available proven technologies that can be deployed and maintained in the open ocean for long periods of time, including a basin scale mooring array, Argo floats, XBT lines, surface drifters and sea level stations. While the focus is on oceanic structure, the meteorological measurements (particularly at moorings) will be extremely valuable to data assimilation issues concerned with weather forecasting and reanalysis efforts. At present there are few such measurements in the Indian Ocean and this lack of information prevents accurate initial condition determination of weather forecasts and limits reanalysis efforts. Development of sustained observations for physical oceanography is ahead of the development required for biogeochemical research. The physical deployments that have already been made and deployments planned for the near future provide an opportunity for biogeochemical oceanography to get started. The aim here is to provide a background to encourage a workshop-discussion on how and why IndOOS should be enhanced with biogeochemical sensors.
12:05-12:30	Mike McPhaden (Development of an Indian Ocean Moored Buoy Array for Climate) Michael McPhaden, NOAA/PMEL, Seattle, WA USA michael.j.mcphaden@noaa.gov This presentation reviews recent efforts to develop an Indian Ocean moored buoy array as part of the Indian Ocean Observing System (IndOOS) in support of CLIVAR and GOOS. Scientific background, array design, and initial steps towards implementation will be described. Preliminary data from equatorial moorings illustrate the prevalence of energetic intraseasonal and seasonal time scale variations. Development of the array offers opportunities for collaborative multi-disciplinary physical and biogeochemical research in key climatic regions of the Indian Ocean basin.
12:30-12:55	Horoshi Kitazato (Investigation on Bio-Geo-Chemical cycles and sedimentary processes at sediment-water interface under Oxygen Depleted Environments: Dive cruise at Indian Margin of the Arabian Sea) Hiroshi Kitazato, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa, Japan kitazatoh@jamstec.go.jp When we have taken an overview the Earth's environmental history since 4.6Ba, two distinct environmental settings have recognized. Earlier half of the Earth's history is characterized by anoxic and/or euxinic environments, whereas the later is well ventilated oxic environment. During the anoxic Earth's environments, it should exist both different biogeochemical cycles and depositional processes in the ocean. For thoroughly understanding these processes at ancient anoxic marine environmental systems, investigation of analogous environment at modern oceans may be the most effective approach to understand. For the purpose to elucidate sedimentary and bio-geo-chemical processes at sediment-water interface (SWI) under oxygen minimum zone (OMZ), we plan to conduct multidisciplinary dive cruise in the Arabian Sea. During the dive cruise, we try to carry out both in situ and laboratory observations, measurements and experiments within and below the OMZ. We try to measure many environmental factors around SWI with manned submersible. Planer optode / microsensor electrode systems and deep-sea stereo camera systems assembled on lander system will be used for monitoring and measuring chemical fluxes around SWI. In situ feeding experiments with 13C- or 15N-labeled organic materials will be carried out for calculating carbon and nitrogen budget around SWI. Precise geochemical analyses and observations will be made for undisturbed sediments that are collected with MBARI-type push cores. Through the series of in situ studies, we are able to understand both bio-geo-chemical and sedimentary processes at SWI under oxygen depleted environments.
12:55-14:00	Lunch
14:00-14:25	Marina Levy (Linking Seacolor to Near-Surface Ocean Dynamics in the Indian Ocean)
14:25-14:50	P.V. Sundareshwar (Establishing IndoFlux: A long-term biogeochemical monitoring network in India) P.V. Sundareshwar1, G. Srinivasan, and S. Singh 1Institute of Atmospheric Sciences, South Dakota School of Mines & amp; Technology, Rapid City, SD 57702 USA, pvs@sdsmt.edu Keywords: IndoFlux, Biogeochemistry, monitoring network, greenhouse gases, environmental Human activity and growth has caused an unprecedented increase in the rate of global environmental change, which have prompted various global advisories and actions. As nations forge ahead with exceptional economic growth, emissions of greenhouse gases and environmental pollution will continue to increase with yet unpredictable consequences. Understanding the impact of diverse environmental stressors and development of efficient mitigating strategies requires an integrated effort of comprehensive long-term data collection, synthesis and analyses, which can also form the basis for informed policy decisions. Globally, various countries have invested in long-term monitoring networks, which have already yielded dividends in terms of robust scientific data that have helped develop defensible resource management guidelines and policies. These global programs are a collection of regional efforts that while providing globally relevant data, also generate vital information that are regionally / nationally important. Currently there are no coordinated multidisciplinary long-term flux towers and biogeochemical monitoring programs in India to help assess the present status of the environment and create a baseline for environmental changes in the future . There are however many activities / programs underway in various agencies that can provide the basis for establishing the proposed long-term biogeochemical monitoring network. Through a series of planning meetings, the Department of Science and Technology (DST), Government of India,.has been coordinating the planning process for establishing a "IndoFlux" network and getting funds allocated for this purpose. The concept has broad multi-agency interest and support, including from the concerned departments of the government. Scientists from India and the United States scientists are developing a blueprint for the IndoFlux through bilateral workshops. Recently we held one such workshop in Chennai under the aegis of the DST, and the Indo-US Science and Technology Forum.  The outcome of the workshop include a scientific plan for the proposed network, a statement of strategic vision, a decision on placement of monitoring stations and an agreement on the instrumentation at these stations. The other consensus opinion that emerged from this meeting was to create an oversight committee, and identify near-term bilateral / multilateral actions for sustained interactions. For India, there is an immediate need to implement an integrated long-term monitoring program that will link terrestrial, coastal and oceanic processes. The proposed network will most certainly provide a map of various sources and sinks for greenhouse gases from diverse Indian ecosystems; provide information and strategies for mitigating domestic emission of these gases; will enable better representation of regional biospheric processes in global and regional climate models improving our ability to predict climate change scenarios; enhance scientific inquiry and education; and help formulate effective policies.
14:50-15:15	Wade McGillis (Air-Sea CO2 Fluxes, the Indian Ocean, and SOLAS) Wade McGillis, Lamont Doherty Earth Observatory, 61 Route 9W, Palisades, NY 10964 USA wrm2102@columbia.edu The Indian Ocean is diverse in its environmental regimes including large fresh water and anthropogenic inputs, lack of direct Arctic water inputs, and extreme monsoon events. Establishing longterm monitoring of atmospheric and oceanic conditions relative to global change in the tropical Indian Ocean region is critical and should be an international collaboration. A contemporary air/sea exchange observation program would capture the wide range of ocean and atmosphere environmental conditions inherent to the Indian Ocean. Such an observational system will provide scientists with information to assess the impact of changing oceanic and atmospheric conditions on regional natural resources and the environment. Integrating Indian Ocean monitoring sites and its data products into the International Global Earth Observation's activities is key to present and future predictive capabilities of climate, weather, and health. Studies using moorings and platforms for long-term measurements of oceanic and atmospheric processes will be presented. Micrometeorological approaches will be discussed that quantify the air/water fluxes of momentum, heat, and gases. The direct covariance, atmospheric profile, and relaxed eddy accumulation methods can be combined with measurements of airside and waterside processes to parameterize gas exchange across the air/water interface. The effect of wind, waves, surface stress, bubbles, rain, solar heating, and surfactants on air-water gas transfer will be explained. Comparisons between the meteorological fluxes and mass balance techniques will be presented to quantify the validity of these results. The variation in the regional/global air-water carbon dioxide fluxes will also be discussed, in particular, the unique features of the Indian Ocean.
15:15-16:15	Convene fourth round of breakout sessions Working groups will be broken out and charged with summarizing the information that has been presented and specifically identifying prominent gaps in our understanding and making recommendations for future research and observations to fill these gaps. Potential working groups: benthic biogeochemistry and ecology, leveraging the CLIVAR/GOOS IO observing system for biogeochemical and ecological studies, moored sensor technologies and possibiities.
16:15-17:00	Convene final group discussion A general discussion will be convened where the participants will be asked to provide recommendations on how to formulate a plan to address the outstanding research questions that they have identified in the preceding days that substantially leverages the planned CLIVAR/GOOS Indian Ocean observing system.
	(Adjourn Workshop)
20:00-22:00	Complimentary Dinner on board “Santa Monica” off Panjim (Mandovi Estuary)
Day 5 (Saturday 7th October)
8:00-13:00	Local field trips and group activities for workshop participants (optional)
9:00-12:00	Convene Scientific Steering Committee Meeting The steering committee will be charged with generating the final products from this workshop. These products will include initiating the development of a plan for future research in the Indian Ocean and organizing a special journal issue based upon the presentations communicated at this workshop. With regard to the research plan, the SSC will recommend members for a new international steering committee that will be specifically tasked with developing a research plan. This document will consolidate all of the information, questions and recommendations that were put forward by the working groups and it will articulate a comprehensive plan for implementing an Ecological/Biogeochemical research program in the Indian Ocean that substantially leverages the planned CLIVAR/GOOS Indian Ocean observing system. A target journal will also be identified for a special issue and guest editors chosen.
	(Adjourn SSC Meeting)

Posters

Sandy Thomalla		Phytoplankton distribution and nitrogen dynamics in the Southwest Indian Subtropical gyre and Southern Ocean Waters S.J. Thomalla, H.N. Waldron, M.I. Lucas, J.F. Read, I.J. Ansorge, E. Pakhomov Department of Oceanography, University of Cape Town, Private Bag, Rondebosch, 7700 During the 1999 Marion Island Oceanographic Survey (MIOS 4), a northbound and reciprocal southbound transect were taken along the Southwest Indian and Madagascar Ridge, between the Prince Edward Islands and 31oS. The sections crossed a number of major fronts and smaller mesoscale features and covered a wide productivity spectrum form the subtropical gyres to subantarctic waters. Associated with the physical survey were measurements of size fractionated chlorophyll, nutrients and nitrogen (NO3, NH4 and urea) uptake rates based on 15N stable isotope tracers. Subtropical waters were characterised by low concentrations of small phytoplankton and low f ratios. Diatom growth is thought to be limited
P. N. Vinayachandran		Simulation of the Indian Ocean sea surface chlorophyll distribution using Regional Ocean Modeling System P. N. Vinayachandran Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bangalore, India, vinay@caos.iisc.ernet.in   The sea surface chlorophyll distribution in the Indian Ocean, particularly in the western Arabian Sea, shows seasonal variations in response to the reversing monsoon winds. Recently available satellite data also show that phytoplankton blooms appear in the oceanic regions around Sri Lanka during summer and in the western Bay of Bengal during northeast monsoon. A coupled physical- biological model based on ROMS (Regional Ocean Modeling System) is used to simulate the climatological seasonal cycle and interannual variations in the Indian Ocean. The Indian Ocean model has a horizontal resolution of half degree in both latitude and longitude and 20 vertical levels. The model is forced by climatological wind, heat and freshwater fluxes followed by interannually varying daily winds from ERA-40 reanalysis for the period 1988-2001. The climatological simulation shows that the model reproduces the climatological seasonal cycle of temperature, salinity, sea surface height anomaly and chlorophyll in the Indian Ocean reasonably well. Comparison of the sea surface chlorophyll with SeaWiFS data shows that the model, in general, tends to overestimate the magnitude of chlorophyll concentration. The models is capable of reproducing the unusually large chlorophyll distribution seen in the equatorial Indian Ocean during the Indian Ocean Dipole event of 1997 although the model chlorophyll distribution is found to extend far too west than in the satellite data. An evaluation of the model simulated chlorophyll with respect to satellite derived chlorophyll data is presented in this study.
Md. Kawser Ahmed		Nutrient and Phytoplankton Dynamics in Northern Bay of Bengal: An Ecological-Physical Coupled Model Approach Md. Kawser Ahmed and Michio J. Kishi Lab. of Ecology, Environment and Climate Change, Department of Fisheries, University of Dhaka, Bangladesh Lab. of Ocean Modelling, Hokkaido University, Japan Abstract In the inshore waters, the interplay of land run-off, tide, currents, and local weather often produces unstable environments, resulting in enhanced temporal variations in productivity of phytoplankton. Phytoplankton bloom in coastal areas is important with respect to trophodynamics and fisheries, and to global bio-geochemical cycles. The transport of organic mater from continental margins to the open ocean plays an important role in the carbon cycle in the oceans. In order to estimate the supply of such organic carbon to the open ocean quantitatively, it is important to make a self-consistent ecosystem model. A time-dependent, three-dimensional self-consistent ecological-physical model was developed to simulate some important biological and physical processes in the northern part of Bay of Bengal. This model will be applied to coastal systems
Balasaheb Kulkarni		Water quality of some selected coastal areas in Mumbai. B.G.Kulkarni, Vikrant Deshmukh, Prasad Kerkar and Ashok Jaiswar Mumbai, a capital of Maharashtra state is located on west coast of India. It is one of the most populated and industralized metropolis in the world. Mumbai originally built on cluster of seven islets is now forms a collected mass of islands. Therefore, most part of it is encircled by Arabian Sea. Daily coastal waters in Mumbai receives voluminous amount of domestic and industrial effluent. During present investigation, water quality parameters like PH, total dissolved solids, turbidity, dissolved oxygen, carbon-dioxide, Biochemical oxygen demand, Chemical oxygen demand, phosphate, nitrate, silicate and salinity, were analyzed in coastal waters from selected areas of Mumbai. The results reveal a high level of phosphate and nitrate in waters of Girgaon and Haji-ali coast than that of nariman point coast. Eventhough coastal water in Giragaon area is showing high turbidity, it harbors diversity of bivalves like Paphia textile, cardita antiquata and cardium asiaticum whereas at nariman point coastal area bivalve Gafrarium divaricatum were recorded. Key words: Mumbai, coastal water, Maharashtra, Arabian Sea B.G.Kulkarni, The Institute of Science, 15 Madam cama Road, Mumbai 400 032, India balasahebk@yahoo.com
Eurico D'Sa		SeaWiFS CDOM Algorithm for a River-Dominated Coastal Margin and Application to OCM Data and the Arabian Sea Eurico D'Sa, Nan Walker and Neha Sharma Department of Oceanography and Coastal Studies Institute, Louisiana State University, Baton Rouge, LA, USA, ejdsa@lsu.edu Keywords: CDOM, ocean color, remote sensing A significant proportion of dissolved organic matter (DOM) is present in coastal and oceanic waters as colored or CDOM in quantities that influence visible band satellite data. Field optical absorption measurements have been used to develop ocean color algorithms and characterize CDOM, which however have been scarce in the Indian Ocean. Using an extensive set of spectral CDOM absorption measurements obtained during numerous cruises along coastal waters influenced by the Mississippi River we apply a regionally developed ocean color algorithm to examine the CDOM dynamics in the northern Gulf of Mexico. SeaWiFS derived CDOM were highly correlated to in situ data with near-shore surface distributions strongly influenced by the seasonal river discharge. SeaWiFS CDOM estimates over the Arabian Sea using the same algorithm indicated seasonal changes and river influences. However, due to limited SeaWiFS data collection over the Indian Ocean, CDOM distribution in the region could potentially be determined using the Oceansat-1 OCM (Ocean Color Monitor) satellite data. A preliminary evaluation and comparison of CDOM estimates using the SeaWiFS and OCM data over the Northern Gulf of Mexico reveals similar patterns of distribution for the two ocean color sensors.  However, issues associated with atmospheric correction and sensor calibration for the OCM sensor needs to be addressed. To exploit the OCM satellite sensor data for determining CDOM distribution in the Indian Ocean, better calibration and validation efforts including the routine field measurements of CDOM spectral absorption is suggested.
Ajoy Kumar		Impact of biases in satellite derived products on the physical and biogeochemical processes in the Indian Ocean. Satellite derived ocean parameters and products have become an integral part of data analysis, along with in situ observations and models, in understanding oceanic processes. One such oceanic parameter, that is also an important indicator for climate change, is satellite derived sea surface temperature (SST), The Indian Ocean (IO) contains a very large body of warm water, second in area only to the western Pacific warm pool. SST averaged over the equatorial IO (5° N to 5°S) are in the range of 301 to 303 k. Recent reports have shown a rapid increase in IO SST but the net heat flux into the ocean has decreased. Other studies have observed a warming trend only in the Southern IO and not in the Northern IO. To understand the dynamical processes controlling the SST increase and how these changes affect the biogeochemical cycles in the IO, we have endeavored to assemble a matchup database consisting of satellite and in situ matchups from a wide range of atmospheres and oceanic regimes. The matchup database also contains aerosol and dust fields from the Ozone Monitoring Instrument (OMI), water vapor fields from Special Sensor Microwave/Imager (SSM/I), windspeed from both the Quicksat and Advanced Microwave Scanning Radiometer (AMSR-E) and various other ancillary fields. Our analysis of this database show large biases in SST related to aerosols and water vapor loadings in the IO. We also show the difficulty of validating these satellite data due to scarce and suboptimum distribution of reliable in situ SST measurements. We emphasize the relevance of CLIVAR/GOOS and other Indian Ocean observing systems in improving and validating satellite derived products in the IO.
Prasad Thoppil		A comparison of mixed-layer dynamics between the Arabian Sea and Bay of Bengal Prasad, T. G. Naval Research Laboratory, Code 7323, Stennis Space Center, , MS 39529, thoppil@nrlssc.navy.mil Keywords: Mixed-layer depth, wind-stress, buoyancy flux, heat and salt fluxes, winter and summer cooling Using a one-dimensional turbulent closure model, we investigate the physical mechanisms governing the seasonal evolution of mixed layer depth (MLD) and sea surface temperature (SST) along two meridional sections; 64.5oE and 88.5oE, which are representative of the open-ocean conditions of the Arabian Sea and the Bay of Bengal. Several perturbation experiments have been performed to isolate and judge exactly the relative importance of wind-stress and buoyancy forcing to the evolution of MLD and SST. The wind-stress forcing is found to be significant during the summer monsoon while buoyancy flux plays a significant role during the winter monsoon. During the summer monsoon (June-September), the MLD in the Arabian Sea deepens to 80 m owing to strong wind-driven vertical mixing, but the weaker winds over the Bay of Bengal restrict the turbulent mixing to a shallow depth of ~30 m. As a result, SST in the Arabian Sea (Bay of Bengal) decreases to ~27oC (remains high ~ 29oC). It is thus the asymmetry in the wind field that is responsible for the difference in MLD and SST between the Arabian Sea and the Bay of Bengal. During the winter monsoon (November-February), the MLD in the Arabian Sea penetrates to deeper than 80 m by convective vertical mixing due to strong negative buoyancy flux (net heat loss), but it is restricted to 40-50 m in the Bay of Bengal owing to reduced net heat loss from the ocean. It is the asymmetry in the buoyancy forcing caused by the difference in latent heat flux that is responsible for the difference in MLD and SST between the Arabian Sea and the Bay of Bengal. The atmospheric parameter that controls this buoyancy difference is the difference in humidity between the two basins.
Etienne Bemanaja		Status and Conservation of Seabirds at Madagascar: Case of Nosy Ve M. Le Corre ECOMAR, Universite de La Reunion, 15 avenue Rene Cassin, BP 7151, 97715 Saint Denis lecorre@univ-reunion.fr and E. Bemanaja Institut d'Halieutique et des Sciences Marines, Universite de Tulear, Madagascar Bemanaja@yahoo.fr This poster details the global status of seabirds in Madagascar: the importance of some species of this resource for the region (Western Indian Ocean), the threat and conservation of the marine avifauna in Madagascar. A pilot study was conducted in January 2004 on the Nosy Ve Island, south western of Madagascar. At Madagascar, Nosy Ve is the only breeding place of the Red-tailed Tropicbirds. This species breeds annually and are traditionally protected (sacred bird) and managed by a local association. Despite the importance threat of seabird in Madagascar, seabird colonies have high ecotourism potential and could generate economic inputs for local population (Case of the population of Red-tailed Tropicbirds at Nosy Ve). This example of sustainable use of seabirds as an economic resource could be developed at most places where seabirds breed, as an alternative to poaching and egg harvesting.
Rohit Srivastava		First Nitrogen based Production measurement in the Southern Ocean Satya Prakash1, Rohit Srivastava1, R.Ramesh1, Rahul Mohan2 and M. Sudhakar2 •1.      Physical Research Laboratory, Navrangpura, Ahmedabad-380009 •2.      National centre for Antarctic and Ocean Research, Vasco-da-Gama, Goa- 403 804 Southern Ocean is now delimited as world's fifth ocean by International Hydrographic Organization (IHO) and comprises of southern portion of the Pacific, Atlantic and the Indian Oceans. Geographically it extends from south of 60°S to the coast of Antarctica. The Southern Ocean is unique in a sense that its surface water contains significant amount of macronutrients like nitrate, silicate and phosphate to support high primary production but still the productivity in this region is very low. Because of this property this region is described as "High Nutrient Low Chlorophyll" or HNLC region (Dugdale and Wilkerson 1991; Martin et. al. 1991; Mitchell et. al. 1991). Several hypotheses have been proposed in the recent past to explain the cause of low biomass and low productivity in HNLC regions despite having lots of potential for high organic production. These hypotheses include grazing control, sun-light limitation, trace metal toxicity, low temperature and Fe-limitation. Although lots of work has been done in the recent past to support the theory of Fe-limitation in this region by carrying out Fe enrichment experiment (Martin et. al. 1991; Mitchell et. al. 1991), almost no work has been done to know the nitrogen biogeochemistry and f-ratio characteristics of this region.      We, for the first time, carried out 15N based experiments in this region to characterize
David Keller		Modeling Dissolved Organic Carbon and Nitrogen Cycling in Oceanic, Coastal, and Estuarine Surface Waters Keller, D. P., University of Maryland Center for Environmental Science Horn Point Laboratory, Cambridge, MD 21613, dkeller@hpl.umces.edu Hood, R. R., University of Maryland Center for Environmental Science Horn Point Laboratory, Cambridge, MD 21613, rhood@hpl.umces.edu Keywords: DOM cycling, DON cycling, DOC cycling, ecological modeling The enormous size and reactivity of the pool of dissolved organic matter (DOM) in marine waters makes it a critical but poorly understood component of global biogeochemical cycling. Understanding the biological, chemical, and physical processes that are involved in DOM cycling is important because small changes in marine DOM can potentially effect a large change in other pools (such as atmospheric CO2). In order to better understand marine DOM cycling we constructed a model to simulate dissolved organic carbon (DOC) and nitrogen (DON) cycling in oceanic, coastal, and estuarine surface waters. The results of running the model in these systems shows that DOM cycling is intricately tied to the biomass concentration, distribution, and production of phytoplankton, zooplankton, and bacteria. We show that in oceanic waters microbial processes are particularly important agents for mediating DOM cycling. In coastal waters microzooplankton and bacteria have the most influence on DOM cycling. In estuarine waters zooplankton have the most influence on DOM production but because estuaries have so much DOM from terrestrial sources DOM cycling is less dependant on interactions between phytoplankton, zooplankton, and bacteria.
Satya Prakash		First Nitrogen based Production measurement in the Southern Ocean Satya Prakash1, Rohit Srivastava1, R.Ramesh1, Rahul Mohan2 and M. Sudhakar2 •1.      Physical Research Laboratory, Navrangpura, Ahmedabad-380009 •2.      National centre for Antarctic and Ocean Research, Vasco-da-Gama, Goa- 403 804 Southern Ocean is now delimited as world's fifth ocean by International Hydrographic Organization (IHO) and comprises of southern portion of the Pacific, Atlantic and the Indian Oceans. Geographically it extends from south of 60°S to the coast of Antarctica. The Southern Ocean is unique in a sense that its surface water contains significant amount of macronutrients like nitrate, silicate and phosphate to support high primary production but still the productivity in this region is very low. Because of this property this region is described as "High Nutrient Low Chlorophyll" or HNLC region (Dugdale and Wilkerson 1991; Martin et. al. 1991; Mitchell et. al. 1991). Several hypotheses have been proposed in the recent past to explain the cause of low biomass and low productivity in HNLC regions despite having lots of potential for high organic production. These hypotheses include grazing control, sun-light limitation, trace metal toxicity, low temperature and Fe-limitation. Although lots of work has been done in the recent past to support the theory of Fe-limitation in this region by carrying out Fe enrichment experiment (Martin et. al. 1991; Mitchell et. al. 1991), almost no work has been done to know the nitrogen biogeochemistry and f-ratio characteristics of this region.      We, for the first time, carried out 15N based experiments in this region to characterize Nitrogen
martin G.D		Abstract     The exchange of phosphorus (P) between water and sinking particles under varying salinity conditions were used to delineate the distribution and sedimentation patterns of P in Cochin Estuary, southwest coast of India. There was a transition in the limiting nutrient from P to N along the salinity gradient (14-24) due to the high internal phosphate cycling during pre monsoon period.  The annual loading of P was high in the estuary due to industrial pollution and increased sedimentation during monsoon season. In contrast, pre monsoon was characterized by high saline incursion and increased re-suspension, which supported release of P from sediments to the overlying waters. Fractionation of the sinking particles revealed that both Calcium and Iron bound P have a vital role in the flocculation of P in the estuary. A 6-fold increase in dissolved P over the past 35 years was found to be responsible for the 4-fold increase in the P levels in the estuarine sediment (5540 µg/g), suggesting an increased P loading. The high level of sediment phosphorus in the present study along with some of the toxic metals reported early, places the region among the polluted estuaries in the world.
Jnanendra Rath		Seasonal variation of phytoplankton of Bay of Bengal, east coast of India Jnanendra Rath P.G. Department of Biotechnology, Utkal University, Bhubaneswar-751004, India (jnanendra@gmail.com) A total of 76 species of phytoplankton, belonging to 70 species of Bacillariophyceae, 4 species of Dinophyceae and 2 species of Cyanophyta frequently occurred in Bay of Bengal. Thallasionema nitzoides, Ditylum sol, Bacteriastrum hyalinum, Rhizosolenia alata, Nitzschia sp., Leptocylindrus danicus, Dinophysis caudatea were the dominant species of phytoplankton. Phytoplankton population in coastal surface waters of Bay of Bengal varied from 19200 nos/l to 89700 nos/l during December, 2005 and 21120 nos/l to 58880 nos/l during April, 2006. The species diversity in terms of species richness, varied from 4 to 16. Relatively higher diversity index was observed at Paradip and lowest diversity index was observed in Chilika. Water quality of Bay of Bengal was analyzed and a correlation between phytopigments and phytoplankton population was established and will be presented along with ecological analysis of phytoplankton of Bay of Bengal.
Gurmeet Singh		Effect of vegetation pattern on Phosphorus fractionation in Lothian mangrove forest, Sundarban, West Bengal, India Gurmeet Singh1*, Al. Ramanathan1, and S.C. Santara2 Sequential extraction studies were carried out in order to assess the biogeochemical behavior of phosphorus in the intertidal sediments of the Lothian Island, Sundarban ecosystem, west Bengal, India. Influence of vegetation pattern on Phosphorus fractionation was evaluated. Sixteen surfacial sediment samples and five surface water samples were collected and analyzed for P fractionation. The vegetation pattern was studied using remote sensing map. Avecennia was the most dominating genus followed by Aegialitis and Pheonix. Inorganic phosphorus was dominant P pool than organic phosphorus in surface water and total P ranged from 15 ppm to 44 ppm. In surfacial sediments, inorganic P and organic P ranged from 280 - 425 µg/g and 259 - 724 µg/g respectively. In Phosphorus fractions, Organic and Detrital P fraction was the dominant one and was influenced by vegetation pattern. Detritus P fraction was more dominant at place with dense mangrove i.e. areas with Avecennia. Organic fraction in sediments showed significant correlation with grasses and Aegialitis. The adsorbed fraction was more in places exposed to anthropogenic activity. Overall, the study reflected that vegetation type, succession and land use pattern has a significant affect on the biogeochemical behavior of Phosphorus. key words: Phosphorus speciation, sediments, Vegetation pattern, Sundarban Affiliation:1 School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 1100672. Dept. of Environmental Sciences, University of Kalyani, Kalyani, West Bengal. Corresponding author: envioguru@yahoo.co.in
M K Sharada		Semi-annual Periodicity in the Tropical Indian Ocean: a diagnostic investigation Yajnik, K. S., Swathi, P. S., Sharada, M. K. CSIR Centre for Mathematical Modelling and Computer Simulation (C-MMACS), Wind Tunnel Road, Bangalore 560037. We have investigated whether semi-annual periodicity is significant in physical, biological and chemical variables in the tropical Indian Ocean by analyzing the climatological simulations of a physical-biological-chemical model (MOM, FDM, and Drange). We have used a fast method to decompose the seasonal anomaly into two orthogonal components, the two components being the even anomaly, having a six-month period, and the balance, or the odd anomaly; and we have used the ratio of variance of the even anomaly to the variance of the seasonal anomaly as a diagnostic. We find that SST, zonal and meridional heat flux in upper ocean, surface heat flux, air-sea carbon flux, primary productivity, phytoplankton, nitrate, and upwelling have large regions in the Equatorial and the Northern Indian Ocean, and a few in the Southern Indian Ocean, where semi-annual periodicity dominates. The paper discusses the role of the directional reversal of monsoons and nonlinearity of certain processes in the mechanisms for these effects. Although improved contemporary models are expected to give more accurate results, the present results are not expected to change materially. Also, since the method is rather general, it can be adapted to study effects of inter-annual variability. Key words: Semi-annual Periodicity, Indian Ocean, Carbon Cycle, Marine Biogeochemistry, Physical Forcing. Contact author: Yajnik K. S., ksy@cmmacs.ernet.in
P S Swathi		A new coupled physical-biological-chemical model for the Indian Ocean P.S.Swathi, T.R.Anderson, M.K.Sharada and K.S.Yajnik We have developed a new coupled model for the Indian Ocean by embedding the biogeochemical model of Anderson and Pondaven (2003) in MOM4 (Griffies et al., 2006). The physical domain extends from 38°E to 100°E, 15°S to 27°N, with a nominal resolution of 0.5° in the longitude and 0.33° in the latitude. There are 35 levels in the vertical with 12 in the top 100m. The model is forced with fluxes computed with bulk formulae and NCAR monthly climatological data. There is no restoring for heat fluxes and mild (60 days) restoring for salinity. Particular attention has been paid to the water fluxes, especially river run off in the head Bay of Bengal. The biogeochemical model of Anderson and Pondaven is a detailed extenstion of FDM (1990) with major emphasis on the DOM cycling. We have applied an OCMIPII - like formulation for chemistry and air-sea transfer of CO2. We compare results of this model with available JGOFS cruise data and buoy data.
Rahul Reddy		Impact of IOD events on Indian Fisheries An anomalous swing in the concentrations of Chlorophyll-A (derived from the Sea WiFS satellite) is noticed along the Indian coats (Arabian and Bay of Bengal) during the years Oct-Nov 1994 and 1997. As is well known that 1994 and 1997 are positive dipole years. The possible impact of the IOD events (1994 and 1997) on the observed phytoplankton swings will be investigated. This is in turn can be used to determine the possible impact of IOD events on the Indian fisheries.
Payal Parekh		Biogeochemical Response of the Indian Ocean to enhanced aeolian iron supply Payal Parekh, University of Bern Fortunat Joos, University of Bern Simon A. Mueller, University of Bern The availability of iron (Fe) exerts a significant control on primary production and the export of organic matter over large areas of the ocean. The input of dust, the major source of iron to the open ocean, has varied significantly in the geological past and may vary in the future due to anthropogenic effects. Using a coarse resolution, but computationally efficient ocean general circulation model (Bern3D GCM), we explore the effect that variations in dust-derived Fe deposition in the Indian Ocean have on global and local export production and iron distribution. Export production in the biogeochemical model is limited by light, temperature, phosphate and iron.
Muzuka Alfred Nizbavuga Nyarubakula		Stable Isotopes Compositions of Organic Carbon and Nitrogen as indicator of pollution in mangrove ecosystem  Alfred N.N. Muzuka Institute of Marine Sciences, University of Dar es Salaam, P.O. Box 668, Zanzibar, Tanzania. E-mail: muzuka@ims.udsm.ac.tz ABSTRACT The stable isotopes compositions of organic carbon (OC) and nitrogen and contents of OC and nitrogen for various mangrove plant species, animals and sediment from polluted (Msimbazi, Mtoni and Maruhubi) and unpolluted (Pete and Wami) mangrove forests in Tanzania are used to asses impact of pollution to the ecosystem. Plant and animals from contaminated sites are enriched in 15N relative to those from uncontaminated. Similarly, sediments from contaminated sites are enriched in 15N relative to the uncontaminated with sediments from Msimbazi being the most enriched in 15N (9.2‰). Animals collected from Msimbazi are most enriched in 15N relative to other animals and mangrove plants from other sites. This results shows that 15N track pollution in the ecosystem. Enrichment in 15N could be a result of utilization of residue nitrogen that is
G.V.M Gupta		The tropical Chilka Laka as a perennial source of carbon dioxide to the atmosphere: Influence of river runoff G.V.M.Gupta, V.V.S.S.Sarma, A.V.Raman, M.Rakhesh, M.Jai Kumar, B.R.Subramanian Dissolved inorganic carbon (DIC), organic carbon (DOC) and pH were measured in Chilka Lake, Asia′s largest brackish water lagoon on the east coast of India, for two seasons during 2005 representing pre- and monsoon conditions. DIC, DOC and pH showed strong spatial disparity associated with salinity distribution. Northern lagoon which is subjected to heavy runoff from surrounding rivers alone accounted for ~80% of total freshwater inflow during monsoon. The lagoon DIC during premonsoon was higher (1200-2400 μmol kg-1) by 20% of monsoon due to seasonal variation of riverine DIC. Lagoon pCO2 (determined through pH and DIC) displayed discernible gradients during monsoon through north (1168-7373 μatm), central (487-2776 μatm) and south (118-790 μatm) sectors. The pCO2 levels and pattern of distribution remained consistent with pCO2 levels in rivers and their discharge rates, being several folds higher during monsoon than premonsoon. As a whole, lagoon pCO2 levels appeared controlled by river runoff, seawater exchange, macrophyte vegetation and community respiration; their levels, specifically in the northern lagoon being defined largely by the magnitude of river discharge whereas community production and respiration influenced the southern lagoon. The CO2 fluxes showed strong seasonal variations ~63-190 times higher during monsoon than premonsoon. A vast export of riverine CO2 during monsoon caused enhanced pCO2 levels in the lagoon (1200-7400 μatm) leading to its large efflux (2797 MgC d-1; Mg=106 g) indicative of lagoon′s potential to pump riverine CO2 to atmosphere than transport it to sea. Keywords: Coastal lagoon, Dissolved carbon, Carbon dioxide, River runoff, Respiration Contact author: G.V.M.Gupta, Ministry of Earth Science, ICMAM Project Directorate, NIOT Campus, Velachery-Tambaram Highway, Pallikaranai, Chennai-601302, India
Jorina Waworuntu		Direct Current and Temperature Measurements in the Alas Strait Jorina M. Waworuntu, Agus Setianto, Windy Prayogo, Teguh Budiman, M. Amrul Husni, PT Newmont Nusa Tenggara, Indonesia The Alas Strait between Lombok and Sumbawa Island is one of the shallow pathways of the Indonesian throughflow to the Indian Ocean. As part of PT Newmot Nusa Tenggara environmental monitoring, since November 2005 continuous current and temperatures were measured using bottom mounted current array recording temporal and vertical variability in the strait. Monthly current averages reveal strong shear between upper and lower layer with northward transport in the upper layer and southward transport in the lower layer. A separate current transect measurement across the strait in 2001 gives total transport estimates up to 0.5 Sv that could be significant in terms of heat and freshwater flux to the Indian Ocean. This southward flow to the Indian Ocean affects the current patterns south of Alas Strait and has particular importance to the submarine tailings placement system operated by PT Newmont Nusa Tenggara, as transport of water mass and any tailings plume at depth has been verified as being offshore. Keywords: current, Indonesian throughflow, Alas Strait, tailings Contact author: Jorina Waworuntu Address: Environmental Department, PT Newmont Nusa Tenggara, Jl Sriwijaya 258, Mataram 83126, Indonesia, email: jorina.waworuntu@newmont.com
Busnur Manjunatha		Understanding secrets of high biological primary productivity in the north-western Indian Ocean B.R. Manjunatha, Department of Marine Geology, Mangalore University, Mangalagangothri-574 199, India The north-western Indian Ocean is one of the high primary productivity regions in the global ocean because of input of nutrients from upwelling and deep convective mixing during the summer and winter monsoons respectively. The continental margins are even more productive and perturbed by anthropogenic activities like silting-up of sediments and accumulation of various types of contaminants such as organics, toxic heavy metals and radionuclides. Signature of eutrophication has been noticed through the blooming of harmful algae in nearshore waters. Emissions of greenhouse gases like CO2, N20 and CH4 from coastal wetlands and open ocean appear to be globally significant. It is appearent that there is a significant mass transport of biogeochemically important elements from continental margins to the open ocean. The main objectives of this study are to identify gaps in our understanding of the quantitative aspects of biogeochemical cycles, particularly carbon and nitrogen, and highlight priority areas research for a better understanding of reasons behind the high primary productivity in the north-western Indian Ocean. More specifically, the relative importance of primary sources of nutrient fluxes with the remineralized ones will be discussed. Similarly, water column circulation, mixing and overturning processes often appeared to be important controlling factors in refluxing nutrients inducing high primary productivity.
Wilford Gardner		Remote sensing of POCW. D. Gardner, Y.B. Son, A.V. Mishonov, M.J. Richardson POC plays a key role in the transport of carbon in the ocean through the biological pump. While CO2 and DOC move with the water, POC can settle through the water column, across isopycnals, scavenging or aggregating other particles and transporting carbon and associated elements to deeper waters.  Thus, POC is a key component in the ocean’s role in sequestering and isolating carbon from the atmosphere. Because POC is produced/cycled on day-to-weeks time scales, a synoptic picture can only be obtained employing remote sensing techniques.  Recently, significant contributions have been made to understanding regional/global distribution of POC in the ocean using SeaWiFS ocean color products and single-wavelength or wavelength ratios of normalized water-leaving radiances Lwn(or remote-sensing reflectance Rrs). Using the ratio of multiple wavelengths to estimate POC concentration yields smaller errors than estimates based on a single wavelength, especially in environments with both Case I and Case II waters. In the Gulf of Mexico, we have developed an algorithm that uses radiance data from 5 wavelengths to provide a more robust estimate of in situ POC over a wide range of POC concentrations.  We seek to collaborate with others working in the Indian Ocean to obtain existing or new POC data collected when SeaWiFS/ MODIS data are available to broaden this approach in developing POC algorithms for the Indian Ocean. Key words: POC, remote sensing, algorithms Contact Author: Wilford Gardner, Texas A& amp;M University, College Station, TX 77843, wgardner@ocean.tamu.edu
Hermann Bange		The nitrogen cycle in the Arabian Sea Hermann W Bange, IFM-GEOMAR, Kiel, Germany (hbange@ifm-geomar.de) The Arabian Sea is one of three major oceanic sites where denitrification in the water column takes place. Therefore, the Arabian Sea is of considerable global significance for our understanding of the past, present and future nitrogen cycle in the ocean. In my presentation the major features of the nitrogen cycle in the Arabian Sea will be presented. Future research areas will be discussed.
Sisir Dash		Uncertainty in chlorophyll-a concentration using the multi-viewing direction mechanism of MISR Sisir Kumar Dash, Tasuku Tanaka Department of Mechanical Engineering, Faculty of Engineering, 2-16-1, Tokiwadai, Ube-shi, Yamaguchi-ken, 755-8611, Japan The synoptic coverage of chlorophyll-a concentration is the key parameter for biogeochemical cycle and carbon cycle in the marine environment. Satellite estimates the chlorophyll-a concentration using traditional algorithms (Gordon et al, 1998) with a fair accuracy and becomes controversial on atmospheric correction. Mostly one direction viewing data is used to estimate surface reflectance and aerosol optical thickness (AOT). But Multi Angle Imaging Spectro Radiometer (MISR) has a capability to observe the ocean surface from different viewing directions, further estimates the ocean surface reflectance and chlorophyll-a concentration. The AOT, available from the MISR archive is compared with the results simulated using 6S radiation transfer code. It turns out that the AOT values agree with each other upto 85% in certain areas in case-1 waters in the northwestern Arabian Sea (Dash et al, 2006). The archive AOT inputted in the radiative transfer process to estimate surface reflectance and further estimates the chlorophyll concentration using in-water algorithm in three viewing directions (Nadir, 26.1° tilt of aft and forward). It is estimated that an error of about 35% is involved in the radiance calibration and AOT, hence with best possibility, surface reflectance is quantified and chlorophyll maps were generated. Interestingly, forward viewing camera overestimates and aft viewing camera underestimates the chlorophyll-a concentration especially in case-1 waters. In case-2 waters, the chlorophyll-a concentration shows similar patterns
V.B. Sarma Yellepeddi		Variability of Chlorophyll-a in the Arabian Sea derived from SeaWiFS.   Y.V.B. Sarma1*, Saiyed I. Ahmed and Adnan Al Azri   College of Agricultural and Marine Science, Department of Marine Science and Fisheries, Sultan Qaboos University, P.O. Box. 34, Al Khod, 123 Muscat, Sultanate of Oman      Abstract   The interannual variability of the surface chlorophyll-a concentration (chl-a) in the Arabian Sea derived from the SeaWiFS ocean color data for the period January 1998 -December 2004 has been examined. Variability in chl-a is centered around southwest and northeast monsoon periods. The mean seasonal chl-a in the western Arabian Sea showed increasing trend from 1998 to 2004. The chl-a data from a few selected locations were subjected to spectral analysis to examine the periodic signals. The annual signal was found to be dominant in the areas affected by only one of the two monsoons. The semiannual signal was predominant in the areas affected by both the monsoons. An empirical model incorporating the annual and semiannual amplitudes of chl-a showed that the ratio of the standard deviations of SeaWiFS to modeled chl-a varied between 0.60 and 0.89, indicating reasonable degree of predictability in chl-a variability in this region.
Jan Robinson		Climate change and fisheries in Seychelles: A review of ecological and socio-economic impacts. Jan Robinson, Vincent Lucas, Liam Campling Climate change impacts fisheries at a variety of scales ranging from small-scale reef fisheries to the largest, industrialized tuna fisheries. This presentation synthesizes and reviews the known and unknown ecological and socio-economic impacts of climate change on fisheries in Seychelles. Habitat modifications brought about by climate-oceanographic anomalies, notably ENSO events, have been short-term in the case of basin-wide pelagic habitats and longer-term in the case of coral reef degradation. Where climate change models predict increased intensity and frequency of ENSO events, permanent phase shifts in habitat structure in shallow and deep water ecosystems would have profound implications for Indian Ocean small-island developing states. A degree of resilience amongst small-scale fishers may enable the artisanal fisheries sub-sector of Seychelles to absorb major phase shifts. By contrast, shifts in the tuna purse seine fleets to the Eastern Indian Ocean and a reduction in Seychelles' strategic importance for this fishery will have consequences for all sectors in the economy. An analysis of the socio-economic effects of past events may provide resource managers with information for modeling impacts of climate change according to existing
Josia Jacob		Biogeochemistry of reactive organic matter in the surface sediments of the western continental shelf of India     Josia Jacoba, K.K.Balachandrana, N. Chandramohanakumarb , T.V. Raveendrana Thresiamma Josepha, Maheswari Naira, C.T. Achuthankuttya   aNational Institute of Oceanography, Regional Centre, Kochi-682 018, India. bDepartment of Chemical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, India.    Abstract             Surface sediments from the western continental shelf of India were analysed for its total organic matter content (TOM), total carbohydrates (TCHO) and proteins (PRT) during late summer (September-October) and premonsoon (March-April) seasons. The region experienced entirely different hydrographical characteristics and productivity patterns during the two seasons. Enhanced surface productivity supported by the prevalent upwelling and a seasonal and shallow suboxic zone were the characteristic features of the shelf during late summer monsoon, whereas the region was oligotrophic and oxygen saturated during premonsoon. During late summer, maximum bulk TOM and reactive OM (TCHO and PRT) was along the transects where active upwelling was observed. Thus establishing a close coupling between sediment organic matter characteristics and the surface ocean productivity. During both the seasons, PRT: TCHO were characteristic of that observed for oligotrophic environments. The percentage of reactive organic matter (TCHO and PRT) did not change significantly during both the seasons. Keywords: surface sediments; western continental shelf of India; Late summer and premonsoon; reactive organic matter Contact author: Josia Jacob, Senior Research Fellow, National Institute of Oceanography, Regional Centre, Kochi-18.
Rishin Basu Roy		Physico-Chemical Condition of Soil and Water in the coastal estuary of Frasergaunge-Bakkhali region. Rishin Basu Roy and Dr. Swapan K. Brahma Keywords: debris, ecology, biodiversity Physico-chemical parameters of the Bakkhali-Frasergaunge region during the dry season (November 05- April 06 ) period have been studied as a part of the programme. Both water and sedimental characteristics have been investigated. This estuary is a well-mixed type. Average pH value varied between 8.4-8.7 at the time of high tide and also in the low tide. But salinity varies between 20.00 - 23.70 during high tide whereas 18.16 - 21.51 at the time of low tide in this area. The conductivity, NO3 1- (N) and PO4 3- (P) were also measured in this region. In addition to these parameters, soil samples in this region have also been analyzed. The texture, water holding capacity and organic carbon were measured. From these values and from the heavy metal analysis (by AAS) pollution load have been calculated. From this study  I have got an idea about the soil and water quality where the investigation shows certain lowering of salinity with respect to the previous ones. The available amount of heavy metals ( bound with the soil organic carbon ) is not high enough but an indication of heavy metal contamination  is there.  Along with this I have also collected the data on the non degradable debris being redeposited on the beach at the time of high tide on the tide line. The amount of non degradable debris present on the beach is also in a significant amount in 2-3 sites. Rishin Basu Roy and Dr. Swapan K. Brahma 6/7 Bijoygarh Kolkata 700 032 2. P.G. Dept. Of Environmental Science, Asutosh College, Kolkta 700026 India, wrishin@yahoo.com and cossimzar@yahoo.com
Allan Devol		A.H. Devol, University of Washington, Seattle, WA USA; devol@u.washington.eduB.X. Chang, University of Washington, Seattle, WA USAS.W.A Naqvi, NIO, Goa, India Nearly all water-column denitrification rate estimates are based upon nitrate disappearance alone, which is mostly determined from N-P stoichiometry. Indeed, only a few measurements of the excess of nitrogen gas produced by denitrification have been made. Here we report measurements of nitrogen gas concentrations in waters from the Arabian Sea and Peru upwelling system along with denitrification rate measurements made by 15NO3 incubations. Nitrogen gas measurements are presented as normalized nitrogen:argon ratios, (N2:Ar)n=(N2:Ar)s /(N2:Ar)e [where (N2:Ar)s is the sample ratio and (N2:Ar)e is the atmospheric equilibrium ratio, such that at equilibrium (N2:Ar)n=1.00]. Profiles from outside the denitrification zone of the Arabian are similar to profiles from other oxygenated waters of the Atlantic, Pacific and Southern Ocean, while within the oxygen deficient zones, there is a distinct maximum in the (N2:Ar)n showing the excess of nitrogen gas over saturation values resulting from denitrification. The fractional excesses were multiplied by the equilibrium saturation gives the actual concentrations of excess nitrogen. Within both the denitrification zone, there was a distinct peak of excess nitrogen in the oxygen deficient zon.. Comparison of the nitrogen gas excess with nitrate deficits resulted in excess nitrogen being about twice as great nitrate deficit in the Arabian Sea while nitrogen excess was about equal to nitrate deficit off Peru.
Toshiro Saino		A Real Time Ocean Primary Productivity Profiling System Toshiro Saino (HyARC, Naogya U. and Japan Science and Technology Agency)   An Ocean Primary Productivity Profiling System, comprising of a Fast Repetition Rate Fluorometer installed on a profiling buoy tethered to an underwater winch is developed.  The system has capabilities of acoustic communication between the profiling buoy and the winch, iridium phone communication between the profiling buoy and the shore based laboratory.  The buoy is normally connected to the winch with latch at ca. 150m and pops up once a day to do profiling according to the pre-set schedule.  The profiling schedule can be altered by sending command over the iridium phone to avoid surface roughness.  The custom made FRRF (Diving Flash) processes the measured fluorescence signal in real-time and transmits a depth profile of temporal value of primary productivity per unit biomass.  Result from the first open ocean deployment (40days, 5200m) will be shown.
Siby Kurian		Short term changes in biomarker patterns in the sediments of coastal Arabian Sea Siby Kurian1*, Borole D.V1, Naqvi S.W.A1, Reshma K1, Ferreira A.M2, Amado J2, Vale C2 1National Institute of Oceanography, Dona Paula, Goa, India, 403 004 2 Institute for Fisheries and Sea Research (IPIMAR), Av. Brasilia, 1400 Lisboa, Portugal Biomarkers are specific organic compounds that can be used to determine the relative contributions of different biological sources and the degradation of organic matter in the suspended matter and sediments. Three short (~1m) sediment cores collected from the coastal Arabian Sea (water depth 25- 45m) and dated with the Pb-210 technique were examined for terrestrial (stigmasterol, β-sitosterol) and marine (phytol, dinosterol etc) biomarkers for reconstructing recent changes in the biogeochemical environment. Downcore variations of stigmasterol and β-sitosterol indicated distinct input of terrestrial matter during recent past. The surface samples showed concentration up to 195 ng/g for  β-sitosterol and 60 ng/g for stigmasterol. Among the fatty acid methyl esters, the saturated  C16:0 was the principal fatty acid (~40-50%), as it is present in many organisms followed by C14:0. The organic carbon content was higher in the near surface layers, presumably caused by higher productivity in the recent past. The cores were also analyzed for biogenic silica, a paleo indicator of diatom productivity and the results showed moderate increase in productivity over the inner shelf. Analysis of trace metals in the same cores reveal increases in terrestrial input in the past few decades. Keywords: biomarkers, FAME, biogenic silica,  Arabian Sea *corresponding author: siby@nio.org
Suryachandra Rao Anguluri		Interannual variability of the thermal domes in the Indian Ocean and its impact on chlorophyll distribution. Suryachandra A. Rao1 and Toshio Yamagata1,2 1Frontier Research Center for Global Change, JAMSTEC, 3173-25 Showa-machi, Knazawa-ku, Yokohama 236-0001, Japan. 2Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan In recent decades couples of thermal domes in the Indian Ocean are identified. Namely, Sri Lanka dome, Southern Indian Ocean dome, and Bay of Bengal dome. The seasonal cycle and dynamics of these domes are well documented. Only recently, the interannual variations of these domes are investigated and the roles of El Nino and Indian Ocean Dipole in modulating this variability are also debated. However, the variability of these domes and their interactions with ocean biology are largely excluded from the recent investigations. In the present work the role of major interannual climate signals in modulating the strength of the thermal domes are investigated using very high resolution ocean general circulation model. It is found that the major modulator for the interannual variability of these domes is the Indian Ocean Dipole. Observed chlorophyll concentrations in these dome regions also show similar variability on interannual time scales and the role of oceanic Rossby waves in bringing this variability are highlighted.
Greg Cowie		Faunal Processing of Sedimentary Organic Matter Across the Pakistan Margin. Clare Woulds, Greg Cowie, Lisa Levin, Henrik Andersson, Jack Middelburg, Peter Lamont, Kate Larkin, Andrew Gooday, Rachel Jeffreys, Christina Whitcraft, Matthew Schwartz Organic matter (OM) burial in sediments is an important term in the global carbon cycle. Benthic faunal activity is a poorly constrained contributing control, and this study aimed to quantify short-term OM processing by benthic faunal communities. The unusual features of the Arabian Sea allowed comparison of sites spanning wide ranges of oxygen and OM concentrations and communities; tracer experiments were conducted at sites (140 to 1850m) spanning the oxygen minimum zone. Algae labelled with excess 13C were added to sediments in-situ and shipboard and, following incubation, sediments were sectioned and fauna and sediments were separated and analysed for 13C. Results showed community respiration and also significant label uptake by macrofauna, foraminifera and bacteria. The importance of these fates varied between sites, and the faunal class responsible for most uptake was heavily influenced by community composition and oxygen availability. At one site, decreased oxygen availability post- vs pre-monsoon was accompanied by a switch from macrofaunal to foraminiferal uptake, but only slight change in community composition. The data suggested that oxygen exerts a threshold control on faunal response to pulsed OM inputs. In addition, natural OM availability and temperature were shown to influence processing of fresh detritus by benthic communities. Keywords: Arabian Sea, Carbon, Oxygen, Fauna, Organic Matter. Clare Woulds, The Grant Institute, Edinburgh University, West Mains Road, Edinburgh, Scotland (Clare.Woulds@glg.ed.ac.uk)
Maria D'Silva		Shifts in Phytoplankton community structure along the south-west coast of India   Authors:  Maria Shamina D'Silva, Arga Chandrashekar Anil, Seshagiri Raghukumar  Contact details: shamina@nio.org, acanil@nio.org, sraghu865@yahoo.co.in   Abstract This region is influenced by southwest monsoon coupled with moderate upwelling and reported to harbor large areas of severely hypoxic waters during September-October. An investigation to understand the implications of such seasonal influences on the biodiversity was carried out. In this paper we present the shifts in the phytoplankton community.  Samples were collected along a transect off Goa and Mangalore on five different occasions between 2002 and 2004. Dinoflagellate (tentatively identified as Heterocapsa sp.) was the most abundant form in hypoxic conditions. In the subsequent post-monsoon sampling, the phytoplankton community was dominated by diatoms such as Chaetoceros curvisetus, Nitzschia seriata and Thalassiosira sp. The pre-monsoon observation indicated the dominance of Trichodesmium erythraeum in surface waters and diatoms in near bottom waters.  Monsoon perturbation appears to be the governing factor in the shifts observed and deserves further evaluation from ecosystem functionality viewpoint. Keywords: phytoplankton, diatoms, dinoflagellates
Ravidas Naik		Title: Phytoplankton community structure in the Bay of Bengal: spatial and temporal variation   Authors: R Naik, S Hegde, A C Anil, K Nisha and VV Gopalakrishna Contact details: rnaik@nio.org, sahana@nio.org, acanil@nio.org, knisha@nio.org, gopal@nio.org Abstract Bay of Bengal is influenced by seasonally reversing monsoon and the characteristics of the water body influenced by riverine discharge. An effort to elucidate the spatial and temporal variation in the phytoplankton community was carried out. The observations were primarily made by utilizing merchant ships plying between Chennai, Port Blair and Kolkatta on several occasions during November 2003 - February 2005.  Surface phytoplankton population showed seasonal variations and the abundance peaked during the beginning of North East monsoon (November) and was characterized by the dominance of dinoflagellates.  During the pre-monsoon, the community comprised of diatoms, dinoflagellates and Trichodesmium.  This presentation provides the details of the spatial and temporal variation and explores the implication and causative factors. Key words: Phytoplankton, Diatoms, Dinoflagellates, Trichodesmium, Northeast monsoon.
Priya D'Costa		Phytoplankton community structure in a mesotrophic, tropical port environment. Priya M. D'Costa, Arga Chandrashekar Anil Contact details: priya@nio.org, acanil@nio.org   Abstract: Changes in phytoplankton community structure in the ports of Mumbai, characterized as mesotrophic, were analyzed during two consecutive post-monsoons and the intervening pre-monsoon period.  The phytoplankton community is dominated by diatoms, with Skeletonema costatum, Thalassiosira spp., Triceratium caudatum, Navicula transitans var. derasa, Pleurosigma angulatum, Pleurosigma elongatum, Surirella ovata and Thalassionema nitzschioides being the most abundant.  A distinct temporal trend was observed only in the occurrence of Rhizosolenia, which was restricted to pre-monsoon and the second post-monsoon period.  Striking temporal changes were evident in dinoflagellates.  The water column was dominated by mixotrophic dinoflagellates during post-monsoon periods whereas heterotrophic dinoflagellates dominated during pre-monsoon.  Analysis based on life-forms indicated that invasive, colonist dinoflagellates (prorocentroids/peridinoids) were predominant in the study area.  The dinoflagellate community during the two post-monsoon periods varied.  Invasive, colonist dinoflagellates dominated following a prolonged, unimodal monsoon whereas nutrient stress-tolerant dinoflagellates (dinophysoids) dominated subsequent to an erratic, short monsoon period.  Monsoon influence was not reflected in the nutrient concentrations during the two post-monsoon periods.  Since large-scale changes in nutrient concentrations, in the range of eutrophic levels, is reported to stabilize the occurrence of certain hetetrotrophic dinoflagellates, the increasing nutrient enrichment in the study area may lead to a change in phytoplankton community structure.   Keywords: phytoplankton, diatoms, dinoflagellates, monsoon
Chetan Gaonkar		Defecation: As a proxy of food for barnacle nauplii Chetan Gaonkar, Arga Chandrashekar Anil* chetan@nio.org, acanil@nio.org   Larval development in most of the acorn barnacles includes planktotrophic naupliar stages.  The food available for these nauplii in the environment can be assessed by the quantification of fecal pellets.  A study was carried out to monitor the temporal changes (July 05- May 06) in the index of larval defecation in a tropical estuary (Zuari, West Coast of India).  Results indicated that the percentage of defecating larvae was comparatively higher during the pre monsoon months.  However, the average number of fecal pellets defecated by a larva remained constant through the period of observation.  The maximal number of larval defecation observed during the pre monsoon months coincided with the reduction in chlorophyll a concentration in the water column.  These observations indicate a possible shift in the food available for the larvae.  The presentation provides the utility of this index in ecosystem evaluation.   Kaywords- Barnacle, larvae, fecal pellets, defecation, chlorophyll,
aninda mazumdar		Biogeochemical processes in shallow marine sediments off Goa coast A. Mazumdar, A. Peketi and P. Rane National Institute of Oceanography Doan Paula, Goa-403004 maninda@nio.org The shallow seismic studies off Goa and Mumbai coasts have indicated the presence of shallow gases1,2 in the shelf region between water depths of 15-30 m. Geochemical analysis of few grab and gravity cores from the region have identified the gas to be predominantly methane2, which is an important hydrocarbon gas. Preliminary estimate suggests existence of 2.6 Terra gram of subsurface methane in the continental shelf sediments of western coast. In order to evaluate the influence of methane on the sediment geochemistry a detailed study of the pore water and solid phase chemistry of cores collected off Goa coast is underway. Preliminary studies indicate extensive sulfate reduction and preponderance of iron sulfide. This is accompanied by high alkalinity and phosphate concentrations. The extent to which sulfate reduction was fuelled by methane and the source of methane is not known. These two aspects constitute the primary objectives of this program. 1Karisiddaiah and Veerayya, 1994. Continental shelf research, 14, 1361-1370 2Karisiddaiah and Veerayya., 1996. Journal of Geophysical Research, 101, 25887-25895 3Siddiquie et al.,1981. Marine Geology, 39, 27-37
ROSHIN RAJ		Role of Mesoscale Eddies in the South Western Indian Ocean and its relation to satellite derived chlorophyll concentration Roshin P.Raj & amp; Benny N.Peter Department of Physical Oceanography Cochin University of Science and Technology Cochin 682016 ,India roshinraj@gmail.com Recently the southwestern Indian Ocean recieves much attention from oceanographers as it is an important region of mesoscale activity.The northern part of the Mozambique channel is the birth place of mesoscale eddies .These eddies are playing a vital role in the distribution of physical,biological and chemical properties of the south western Indian Ocean as well as the inter-oceanic exchange of tropical surface thermocline waters between Indian and Atlantic Oceans through the strong western boundary currents.The present study is confined to the south Indian Ocean region between the Latitude 10°S – 40°S and Longitude 25°E – 65°E. Considering the importance of mesoscale activity in the south western Indian Ocean , a comprehensive investigation has been carried out to understand the distribution and variability of the water characteristics in relation to mesoscale eddy.The high resolution Maps of Sea Level Anomaly (merged T/P or JASON and ERS1/2 or Envisat) during 1999 January – 2003 January have been used,along with the World Ocean Circulation Experiment (WOCE) hydrographic sections (io4S) and XBT sections,and SeaWifs data( chlorophyll-a) (1999-2003). The instantaneous velocity field computed for every seven days from 1999-2003 using mean velocity field of ( Benny et al. 2005 ) and the time series altimeter derived velocity anomaly displays the initiation growth and dissipation of the mesoscale features.
Krothapalli Somasundar		Meso-scale Eddies in the Northern Arabian Sea during the winter. Krothapalli  Somasundar Department of Ocean Development, Block-12, CGO Complex, Lodi Road,  New Delhi 110 003, India, Tel -091-11-24361068 (email: soma@nic.in) ABSTRACT           Analysis of a suite of high-resolution images of Ocean Colour Monitor (OCM) (IRS-P4) and AVHRR (NOAA) reveals that the occurrence of a widespread meso-scale eddies is evident in the northern Arabian Sea, particularly during the winter months (November to February). Although the formation of eddies have been reported earlier, the magnitude and frequency both cold and warm water eddies are relatively unknown, which appear to play an important role in the fluxes of heat and mass in to the atmosphere from the Arabian Sea.  The recent studies during the JGOFS programme reveal that the biological productivity as a result of winter convection in the northern Arabian Sea is found to exhibit a great deal of inter-annual variability.  In order to make a qualitative assessment these fluxes caused due to mesoscale eddies in the surface water of Arabian Sea, which appears to vary significantly, both in terms of space and time scales an attempt has been made to study the cold and warm eddies formed during winter using both multiple sensor satellite data and in-situ data.     The thermal bands of AVHRR and visible channels of OCM images suggested that the maximum numbers of cold-water eddies were observed during February-March compared to the rest of the winter.  The size of the cold water eddies in the Arabian Sea ranges from
M.R.Ramesh Kumar Pai		Comparison of Precipitation Estimates over the Tropical Indian Ocean     M.R.Ramesh Kumar Pai and Baluchandran Physical Oceanography Division National institute of Oceanography Dona Paula, Goa - 403004.   Abstract   The precipitation over the tropical Indian Ocean is studied using three satellite estimates of rainfall [ Climate Prediction Centre Merged Analysis Precipitation (CMAP), Global Precipitation Climatology Program (GPCP) and Tropical Rainfall Measuring Mission Microwave Imager (TMI)] and the NCEP/NCAR Reanalysis (NRA) data for the period 1998-2005. The annual climatology of rainfall for the study period showed significant differences with the TMI showing the maximum rainfall over the Eastern Equatorial Indian Ocean (EEIO) of about 6400 mm/year and the NRA showing the lowest values in the EEIO region of about 1500 mm/ year. Annual cycle of rainfall over the Arabian Sea and Bay of Bengal showed that the differences were maximum during the months, June to December with the TMI values about two to three times that of the other estimates. During the period January to April, the TMI estimates were lower than other estimates.
Shailaja M.S.-Murthy		Pelagic denitrification in the Arabian Sea: probable biochemical processes Shailaja, MS More than a third of the global nitrogen removal is believed to occur in the oxygen-depleted zones of the oceans. This denitrification is performed mainly by facultative anaerobic bacteria that utilize organic (heterotrophic denitrification) or inorganic (autotrophic nitrifier denitrification) compounds as electron sources to reduce nitrate. A recently described autotrophic bacterial process ('anammox')  involves the anaerobic oxidation of ammonia by nitrite resulting in complete fixed nitrogen removal with no organic electron source requirement. Investigations of the potential activity profiles of some key enzymes mediating nitrification [ammonia monooxygenase (AMO)] and denitrification [nitrate reductase (NaR) and nitrite reductase (NiR)] in the Arabian Sea oxygen minimum zone (OMZ) in relation to oxygen (O2) and the intermediates of denitrification viz., nitrate, nitrite and nitrous oxide (N2O) revealed that the dissimilatory nitrate reduction activity was generally very low or absent within the Persian Gulf Watermass (PGW). Also, within the PGW, N2O is formed through nitrifier denitrification rather than heterotrophic denitrification, and builds up possibly due to inhibition of its consumption by O2. Classical and nitrifier denitrification occur in discrete layers, as suggested by the opposing trends in NaR and AMO activities, while Anammox  could be one of the reasons for the presence of appreciable nitrate deficit within the core of PGW.                  Incubation experiments showed that the rate of formation and consumption of N2O within the intensely denitrifying waters is influenced, to a large extent, by the quality of dissolved organic matter present in the water.
Balu Chandran		Comparison of Precipitation Estimates over the Tropical Indian  Comparision of Precipitation Estimates over the Tropical Indian Ocean  M.R.Ramesh Kumar and Balu Chandran Physical Oceanography Division National institute of Oceanography Dona Paula, Goa – 403004. Abstract The precipitation over the tropical Indian Ocean is studied using three satellite estimates of rainfall [ Climate Prediction Centre Merged Analysis Precipitation (CMAP), Global Precipitation Climatology Program (GPCP) and Tropical Rainfall Measuring Mission Microwave Imager (TMI)] and the NCEP/NCAR Reanalysis (NRA) data for the period 1998-2005. The annual climatology of rainfall for the study period showed significant differences with the TMI showing the maximum rainfall over the Eastern Equatorial Indian Ocean (EEIO) of about 6400 mm/year and the NRA showing the lowest values in the EEIO region of about 1500 mm/ year. Annual cycle of rainfall over the Arabian Sea and Bay of Bengal showed that the differences were maximum during the months, June to December with the TMI values about two to three times that of the other estimates. During the period January to April, the TMI estimates were lower than other estimates.
Abdul Rahiman Sheik		Molecular manipulation techniques for ecological investigations in the littoral zone The advent of molecular biology and developments in molecular manipulation techniques have revolutionized the way ecological investigations can be planned, executed and understood. For example, sediment ecosystem with its diverse microbial populations is an interesting one to look for unique microbial populations. Green Sulfur bacteria are the part of the benthic/sediment microflora of pivotal importance in chemoautotrophy and sulfur cycling. One objective of the present proposal is to apply relevant techniques for anoxic sediments in the well littoral zone depths. For this DNA from the chosen sediment samples will be extracted following established protocols. Then the PCR amplication of the 16S rRNA gene specific to the green-sulfur bacteria will be performed by utilizing the primers specific to them.The amplified fragments will be separated by Gel Electrophoresis and will be sequenced for comparison and further analysis.
Syam Sankar		Onset of the Southwest Monsoon Over Kerala : Role of Low Pressu Onset of the Southwest Monsoon Over Kerala : Role of Low Pressure Systems M.R.Ramesh Kumar1, Syam Sankar1 and Chris Reason2 1Physical Oceanography Division, National Institute of Oceanography, Dona Paula, Goa, India. 2 Oceanography Department, University of Cape Town, South Africa. Abstract The synoptic conditions over the Eastern Arabian Sea (EAS) and South Eastern Arabian Sea (SEAS) in particular associated with the Monsoon Onset over Kerala (MOK) were studied using the mid tropospheric relative humidity (RH at 500 hPa), vertical shear of the horizontal winds and relative vorticity from the daily NCEP/NCAR Reanalysis data for the period 1970-1998. Our comprehensive study using the above three important cyclogenesis parameters, clearly brings out for the first time that neither the Low Pressure System (LPS) nor the Monsoon Onset Vortex (MOV) play a major role on MOK, as in majority cases during the study period none of the conditions were conducive for the formation of a LPS or MOV to trigger the MOK. Further, in several years it was seen that MOV usually formed after the MOK and helped in progress of the Monsoon over the Indian subcontinent.
jagruti vedamati		Study of nitrous oxide cycling in estuarine sediments of the Mandovi estuary of Goa  To study some aspects of nitrous oxide cycling in estuarine sediments, four intertidal sites were chosen in Mandovi estuary of Goa. Separate sediment cores were collected for pore water N2O, nutrients and porosity. N2O in pore water was found to be coupled with NO2 -which is an intermediate product of both nitrification and denitrification process. High concentrations of NO3- in overlying water ( 16.69µM) and low values in the upper sediment layers (0.76µM) indicate intense denitrification. Low N2O concentration in upper 10cm ( 3.73 nM) may be because of its rapid conversion to N2 gas and higher concentration in the layer below 10cm (~112 nM ) along with accumulation of NO2- ( 3.96µM) suggests its production via nitrification from ammonia rich pore water. Nitrification and denitrification processes in upper sediment layer may be closely coupled which is evidenced by lack of correlation between NO3-, NO2- and N2O. Low concentrations of N2O in overlying water (~6.9nM) and in the upper layers of sediment column indicates that sediment may not be a major source of N2O to bottom water.
Purnachandra Rao venigalla		Microbial processes in the formation of marine phosphorites. V. Purnachandra Rao National Institute of oceanography, Dona Paula - 403 004, Goa, India Phosphorites occur on many continental margins, both in upwelling and non-upwelling regions and also on isolated seamounts, plateaus, ridges and other elevated portions of the seafloor. Dissolved (inorganic/organic) phosphorus in seawater ranges between < 0.1 to > 3 mM, but within the interstitial waters of upwelling regions the concentration can be at least an order of magnitude higher. Although both inorganic and organic processes have been implicated in the formation of ore-grade phosphorites (18% P2O5) in different sedimentary environments, there still exists considerable debate in the literature in this regard. Here I document evidences of microbial activity in phosphorites collected from the continental margins of India, a seamount and a ridge in the Arabian Sea. We demonstrate that the phosphorites from the eastern margin of India serve as Quaternary analogues of ancient stromatolitic phosphorites and suggest that microbial processes play a major role in phosphorite formation.
Adnan Al-Azri		SEASONAL AND SPATIAL DISTRIBUTION OF CHLOROPHYLL-a AND NUTRIENT DYNAMICS IN THE COASTAL REGION OF THE GULF OF OMAN.    Adnan Al-Azri1, Saiyed Ahmed1, Sarma Y.V1, Khalid. Al-Hashmi1, Harub Al-Habsi1, Salim Al-Khusaibi1   1Sultan Qaboos University, College of Agricultural and Marine Sciences, Muscat, Sultanate of Oman (adnazri@squ.edu.om, ahmedsi@squ.edu.om, sarma@squ.edu.om, Khalid99@squ.edu.om, harib99@squ.edu.om, salimk@squ.edu.om)     The oceanography of the Gulf of Oman appears to be quite variable, complex, and poorly known. Based on the available oceanographic data, there are few, mostly short term studies of Chl-a and nutrients in the Gulf of Oman. The present study investigates seasonal and spatial distributions of Chlorophyll-a (Chl-a) and dissolved inorganic nutrient at three stations (F, OFF, and BK) in the coastal region of the Gulf of Oman during 2005. Water samples were collected at least twice a month during the study period at 1m depth.  The results show seasonality of Chl-a, water temperature and dissolved inorganic nutrient. Water temperature showed gradual increase from winter to summer with values ranging between 23°C and 32°C.  A significant drop (8°C) in water temperature was recorded during summer at all stations indicating the intrusion of upwelling water. Chl-a showed two major peaks during spring and fall and low concentrations during summer and late winter. The highest Chl-a concentrations at the three stations (1.5, 0.7, and 1.2 µg/l respectively) were recorded in early spring and the lowest (≤0.02 µg/l) during winter. Nitrate, nitrite and phosphate showed maximum concentration during winter (9.0, 1.3, and 1.2µM respectively) followed by a gradual decline during the rest of the year. No statistically significant correlations were found between Chl-a and inorganic nutrients, however water temperature exhibited significant inverse correlation with inorganic nutrients.
Moturi Srirama Krishna		Foraminiferal Mg/Ca as proxy of paleo SST in the Indian Ocean   M. Sri Rama Krishna*,#, Sk.G. Pasha#, Nittala S. Sarma#, M.G. Yadava@ and V. Balaram$ #Marine Chemistry Laboratory, School of Chemistry, Andhra University,  Visakhapatnam-530 003, India @Earth, Planetary and Geosciences Division, Physical Research Laboratory, Navranpura, Ahmedabad-380 009, India $ Geochemistry Division, National Geophysical Research Institute, Hyderabad-500 007, India   Abstract:   A 5 meter long gravity sediment core raised from the equatorial Indian Ocean at a water depth of 4057 m, was examined for foraminiferal geochemistry in order to decipher paleo sea surface temperature variations during the last 350 ka.  The stratigraphy of the core was established by radiocarbon dating of coarse fraction and d18O of planktonic foraminifer Globigerinoides sacculifer.  In this core Pleistocene sea level fall could bring the core-top close to the lysocline depth and thus CaCO3 could undergo episodic dissolution there.  The Mg/Ca ratio in Globigerinoides ruber (150-300 μ size fraction) white of this core is used as a potential proxy of paleo sea surface temperature.  The distribution of Mg/Ca ratio in G. ruber is in synchronous with d18O.  The Mg/Ca ratio varied between 3.03 and 6.07 mmol mol-1 with an average of 4.13 mmol mol-1.  A characteristic distribution is the abrupt maxima of the ratio (average 5.84 mmol mol-1) at 350-400 cm bsf that infers an abrupt increase in sea surface temperature of as much as 1 oC in the OIS 7 to 8 interface.   Such abrupt increase in Mg/Ca ration may be due to either dissolution
Gaute Lavik		Anammox bacteria in the Arabian Sea OMZ Gaute Lavik, Phyllis Lam, Wajih Naqvi and Marcel Kuypers NIO, Dona Paula, India, In many oceanic regions, growth of phytoplankton is nitrogen limited because fixation of N2 cannot make up for the removal of fixed inorganic nitrogen (NH4+, NO2-, NO3-) by anaerobic microbial processes. Globally, 30-50% of the total nitrogen loss occurs in oxygen-minimum zones (OMZs). The Arabian Sea OMZ is regarded to be one of the main areas of N-loss. This fixed nitrogen loss is commonly attributed to denitrification (reduction of nitrate to N2 by heterotrophic bacteria). The anaerobic oxidation of ammonium with nitrite to N2 (anammox), was recently recognized as a major sink for fixed inorganic nitrogen in coastal sediments and in anoxic waters of basins isolated from oxygenated deep circulation.  Moreover, recent results show that anammox bacteria are responsible for massive loss of fixed nitrogen as gaseous N2 from the Benguela OMZ water as well the Peru/Chile OMZ. Here we provide DNA based evidence for the presence of anammox bacteria in the main OMZ waters of the Arabian Sea. Phylogenetic analysis of the 16S rRNA sequences showed that these  anammox bacteria from the Arabian Sea are closely related to Cadidatus `Scalindua sorokinnii' previously found in the Black Sea and Benguela OMZ.

Organizers

US: Raleigh Hood, Chair (University of Maryland), Lou Codispoti (University of Maryland), Jay McCreary (University of Hawaii), Ajit Subramaniam (Lamont-Doherty Earth Observatory, Columbia University), Jerry Wiggert (Old Dominion University)

International: Wajih Naqvi, co-Chair (National Institute of Oceanography, Goa, India), Satish Shetye (Director, National Institute of Oceanography, Goa, India), Dileep Kumar (National Institute of Oceanography, Goa, India), Prasanna Kumar (National Institute of Oceanography, Goa, India), V.S.N. Murty (National Institute of Oceanography, Goa, India)

Sponsors

National Science Foundation	National Institute of Oceanography (Goa, India)
INDO-US S&T Forum (Indo-US Science and Technology Forum)	SCOR (Scientific Committee on Oceanic Research)
IOC Perth (the Perth Office of the Intergovernmental Oceanographic Commission of UNESCO)	IOGOOS (Indian Ocean Global Ocean Observing System)

IMBER (Integrated Marine Biogeochemistry and Ecosystem Research)
WIOMSA (Western Indian Ocean Marine Science Association)
CLIVAR/GOOS (An International Research Programme on Climate Variability and Predictability/The Global Ocean Observing System)
IOCCP (International Ocean Carbon Coordination Project)

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