In Chesapeake Bay in the United States, decades of management efforts have resulted in modest reductions of nutrient loads from the watershed, but the corresponding improvements in estuarine water quality have not consistently followed. Generalize additive models were used to directly link river flows and nutrient loads from the watershed to nutrient trends in the estuary on a station-by-station basis, which allowed for identification of exactly when and where responses are happening.

Read more

Nitrogen, a critical element in all forms of life, is continuously being passed from nonliving to living matter and then back again, but an excess of this nutrient can have adverse effects on aquatic environments. An understanding of the past, present, and future sources, movement, and fate of nitrogen in the Chesapeake Bay watershed can help inform efforts to bring this cycle back into balance (fig. OV.1).

Read more

This newsletter was created in collaboration with the Chesapeake Bay Science and Technical Advisory Committee (STAC) to summarize the rational for the STAC Rising Water Temperatures workshop.

Read more

The aim of this report card is to provide a transparent, timely, and geographically detailed assessment of 2019-2020 Coastal Bays health. Coastal Bays health is defined as the progress of four water quality indicators (total nitrogen, total phosphorus, chlorophyll a, dissolved oxygen) and two biotic indicators (seagrass, hard clams) toward scientifically derived ecological thresholds or goals.

Read more

The Darwin Harbour Integrated Report Card has been developed through extensive consultation with stakeholders from the Darwin Harbour region and relies heavily on their knowledge and expertise. Initiated by the Darwin Harbour Advisory Committee, a series of workshops were held in March 2020, representing the first step in this report card journey.

Read more

Effective stewardship of ecosystems to sustain current ecological status or mitigate impacts requires nuanced understanding of how conditions have changed over time in response to anthropogenic pressures and natural variability. Detecting and appropriately characterizing changes requires accurate and flexible trend assessment methods that can be readily applied to environmental monitoring datasets. A key requirement is complete propagation of uncertainty through the analysis.

Read more

In the annual IAN Report Card, IAN staff reflect on accomplishments from 2020. The self-assessment is based on indicators in three categories: social impacts, ecological outcomes, and partner engagement. Overall, IAN received an overall grade of C (78%) which is a decrease from the 2019 score of B (84%).

Read more

Environmental monitoring programs generate multivariate time series for the assessment of ecosystem health. Recent developments in causal inference offer ways to translate these observational data into networks able to explain gains and losses in the trajectories of indicator variables. Here, we present a case study of this approach using surface water dissolved oxygen (DO) criteria attainment across the Chesapeake Bay.

Read more

In the Chesapeake Bay, excess nitrogen (N) from both landscape and atmospheric sources has for decades fueled algal growth, disrupted aquatic ecosystems, and negatively impacted coastal economies. Since the 1980s, Chesapeake Bay Program partners have worked to implement a wide range of measures across the region—from the upgrading of wastewater treatment plants to implementation of farm-level best management practices—to reduce N fluxes to the Bay.

Read more

Extensive efforts to adaptively manage nutrient pollution rely on Chesapeake Bay Program’s (Phase 6) Watershed Model, called Chesapeake Assessment Scenario Tool (CAST), which helps decision-makers plan and track implementation of Best Management Practices (BMPs). We describe mathematical characteristics of CAST and develop a constrained nonlinear BMP-subset model, software, and visualization framework.

Read more