How sensitive are systems in the Chesapeake Bay to acidification and nutrient pollution?

Jeremy Testa, University of Maryland

The wild oyster industry has suffered repeated collapses in the Chesapeake Bay due to overharvesting, disease, and declining environmental conditions. How future conditions will affect the Eastern oyster remain uncertain, not only because these conditions such as increased freshwater are difficult to predict , but also because the interactions between stressors such as ocean acidification, temperature, nutrient runoff and sea level rise could lead to unexpected chemical, biological, and economic change. The changes in stressors and their impacts do not always proceed in a straight line.The potential responses of various life stages of the Eastern oyster to stressors like acidification and eutrophication has received little attention. This project will study the impact of different stressors to Chesapeake Bay, a large estuarine system, and the Eastern oyster. The study will bring together different models to understand the relationship between biogeochemical cycling of carbon, oxygen, and nutrients, oyster growth and survival, and oyster economic profitability in the Chesapeake Bay ecosystem. The project will provide insights into future conditions and habitats where aquaculture and wild oyster populations may be most vulnerable to the climate and ocean changes.
Tuesday, October 2, 2018

Low pH in Coastal Waters of the Gulf of Maine: A Data Synthesis-Driven Investigation of Probable Sources, Patterns and Processes Involved

David W. Townsend, University of Maine

Coastal Maine supports valuable lobster, clam, oyster and other shellfish industries that comprise >90% of Maine’s record $616M landed value last year. Earlier monitoring efforts in Maine and New Hampshire have documented periods of unusually acidic conditions in subsurface waters of Maine’s estuaries, which may be driven by episodic influxes of waters from the Gulf’s nutrient-rich, highly productive coastal current system. Sources of acidity to the estuaries also include the atmosphere, freshwater fluxes, and local eutrophication processes, all modulated by variability imparted by a number of processes.This project is a data synthesis effort to look at long-term trends in water quality data to identify the key drivers of acidification in this area. Extensive data sets dating back to the 1980s (including carbonate system, hydrography, oxygen, nutrients, and other environmental variables) will be assembled, subjected to QA/QC, and analyzed to assess acidification events in the context of landward, seaward and direct atmospheric sources, as may be related to processes operating on tidal to decadal timescales. Such analyses are requisite for any future vulnerability assessments of fishery-dependent communities in Maine and New Hampshire to the effects of coastal acidification.

Friday, December 22, 2017