The impact of the herbicide diuron on photosynthesis in three species of tropical seagrass (Page 1)

The impact of the herbicide diuron on photosynthesis in three species of tropical seagrass

Haynes D, Ralph P, Prange J, and Dennison WC ·
2000

The impact and recovery from exposure to the herbicide diuron [DCMU; 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea] was assessed for three tropical seagrasses, maintained in outdoor aquaria over a 10-day period. Photosynthetic stress was detected using chlorophyll a fluorescence, measured with a Diving-PAM (pulse amplitude modulated fluorometer).


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Sediment-based reconstruction of submersed aquatic vegetation distribution in the Severn River, a sub-estuary of Chesapeake Bay (Page 1)

Sediment-based reconstruction of submersed aquatic vegetation distribution in the Severn River, a sub-estuary of Chesapeake Bay

Arnold RR, Cornwell JC, Dennison WC, and Stevenson JC ·
2000

A paleo-ecological reconstruction of long-term changes in the distribution of submersed aquatic Vegetation (SAV) in a Chesapeake sub-estuary was made using dated sediment cores on transects going from shallow (< 0.5 m) to deep (> 2 m) waters. Maynedier and Saltworks Creeks, branches of the Severn River, have had substantial losses of SAV, similar to many parts of the upper Chesapeake Bay.


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Utilization of nitrogen and carbon by phytoplankton in Moreton Bay, Australia (Page 1)

Utilization of nitrogen and carbon by phytoplankton in Moreton Bay, Australia

O'Donohue MJ, Glibert PM, and Dennison WC ·
2000

Water samples were collected within river mouths, at river plume sites and at well flushed ocean-influenced sites within Moreton Bay, a shallow subtropical embayment in south-eastern Queensland. Rates of inorganic nitrogen (NH4+ and NO3-) and carbon uptake were determined across temporal and spatial scales by use of N-15 and C-14 incorporation. Phytoplankton productivity, measured as CO2 uptake, was highest at the river mouths.


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Physiological responses of five seagrass species to trace metals (Page 1)

Physiological responses of five seagrass species to trace metals

Prange JA and Dennison WC ·
2000

Trace metal run-off associated with urban and industrial development poses potential threats to seagrasses in adjacent coastal ecosystems, Seagrass from the largest urban (Moreton Bay) and industrial (Port Curtis) coastal regions in Queensland, Australia were assessed for metal concentrations of iron (Fe), aluminium (Al), zinc (Zn), chromium (Cr) and copper (Cu), Trace metal concentrations in seagrass (Zostera capricorni) leaf and root-rhizome tissue had the following overall trend:


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Effect of the seagrass Zostera capricorni on sediment microbial processes (Page 1)

Effect of the seagrass Zostera capricorni on sediment microbial processes

Hansen JW, Udy JW, Perry CJ, Dennison WC, and Lomstein BA ·
2000

The effect of the seagrass Zostera capricorni on sediment microbial processes was studied in a tank experiment, where vegetated and unvegetated control sediments were incubated in 10 and 50% of incident light. Leaf and root-rhizome biomass, shoot density, and leaf productivity were significantly higher when plants were incubated in 50 % than in 10 % of incident Light.


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Responses of seagrass to nutrients in the Great Barrier Reef, Australia (Page 1)

Responses of seagrass to nutrients in the Great Barrier Reef, Australia

Udy JW, Dennison WC, Long WJL, and McKenzie LJ ·
1999

Declines in seagrass biomass and growth have been widely reported in response to anthropogenic impacts. In contrast, the distribution and biomass of seagrass in the carbonate sediment around Green Island reef, part of Australia's Great Barrier Reef (GBR), has measurably increased during the past 50 yr, possibly due to increases in the availability of nutrients from local and regional anthropogenic sources.


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Within canopy growth strategies of the two seagrass species Amphibolis griffithii (J. Black) den Hartog and Amphibolis antarctica (Labillardiere) Sonder & Ascherson ex Ascherson (Page 1)

Within canopy growth strategies of the two seagrass species Amphibolis griffithii (J. Black) den Hartog and Amphibolis antarctica (Labillardiere) Sonder & Ascherson ex Ascherson

Carruthers TJB ·
1999

Responses in leaf production to variation in light climate throughout Amphibolis griffithii and A.antarctica canopies were studied at Rottnest Island, Western Australia. To test the importance of small scale changes in the physical environment (e.g. light, temperature and water movement) within the canopy, leaf production rates at different heights within the canopies and Radiation Use Efficiency (RUE), for the entire canopy of each species, were calculated and compared.


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Sensitivity of transects across a depth gradient to measuring changes in aerial coverage and abundance of Ruppia megacarpa Mason (Page 1)

Sensitivity of transects across a depth gradient to measuring changes in aerial coverage and abundance of Ruppia megacarpa Mason

Carruthers TJB and Walker DI ·
1999

Effective management of estuarine systems that contain submerged aquatic macrophytes, requires knowledge of whether macrophyte populations are stable, increasing or decreasing in terms of aerial coverage and abundance. This study established three transects within Wilson Inlet and monitored them five times during 1996 for percent cover of Ruppia megacarpa and maximum depth limits of these meadows.


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