Understanding the vulnerability of shellfish hatcheries in the Chesapeake Bay to acidification

MARJORIE FRIEDRICHS, VIRGINIA INSTITUTE of MARINE SCIENCE

Acidification in brackish estuarine environments, such as the Chesapeake Bay, is intensified by coastal inputs such as runoff, atmospheric pollution and freshwater sources. The Chesapeake Bay is home to commercial shellfish hatcheries that supply seed that is sold to and planted in hundreds of shellfish farms within the Chesapeake. A great deal of research has been dedicated to understanding the impact of acidification on shellfish, and has shown even greater impacts to shellfish growth and survival in lower salinity and nutrient-rich environments. The shellfish industry relies on consistent hatchery production to sustain and expand operations that could greatly benefit from regional OA forecasts and metrics. This project will synthesize recent CO2 system observations with long-term water quality parameters and combine observations an existing baywide, high-resolution 3D model. The proposed research will develop forecasts of acidification and develop acidification metrics tailored to support decision-making needs of commercial shellfish hatchery and nursery operators.


Wednesday, April 15, 2020

Ocean Acidification at a Crossroad– Enhanced Respiration,Upwelling, Increasing Atmospheric CO2, and their interactions in the northwestern Gulf of Mexico”

Xinping Hu, Texas A&M University-Corpus Christi

Among the NOAA designated Large Marine Ecosystems, the Gulf
of Mexico (GOM) remains poorly understood in terms of its current OA conditions, despite its
ecological and economic significance. In the northwestern GOM (nwGOM), decadal
acidification has been observed in the shelf-slope region, with metabolic production of CO2
contributing to a larger fraction of CO2 accumulation than uptake of anthropogenic CO2, and the
observed rate of acidification is significantly greater than that in other tropical and subtropical
areas. Unfortunately, whether the observed OA in this region represents a short-term
phenomenon or a long-term trend is unknown.
It is hypothesized that increasing atmospheric CO2, increasing terrestrial nutrient export
due to an enhanced hydrological cycle, and enhanced upwelling due to climate change will cause
the continental shelf-slope region in the nwGOM to acidify faster than other tropical and

subtropical seas. In order to test this hypothesis wave gliders, in -stiu sensor along withe underway measurements from research vessels will measure carbonated chemistry in in surface and shallow  waters. Modeling will be used tp integrate the chemical signals into the models to hindcast/predict spatia; and temporal variation of the OA signal for the the optimization of monitoring design and implementation.

Tuesday, March 3, 2020

Optimizing Ocean Acidification Observations for Model Parameterization in the Coupled Slope Water System of the U.S. Northeast Large Marine Ecosystem

Grace Saba, Rutgers University

The U.S. Northeast Shelf Large Marine Ecosystem, supports some of the nation’s most economically valuable coastal fisheries, yet most of this revenue comes from shellfish that are sensitive to ocean acidification (OA). Furthermore, the weakly buffered northern region of this area is expected to have greater susceptibility to OA. Existing OA observations in the NES do not sample at the time, space, and depth scales needed to capture the physical, biological, and chemical processes occurring in this dynamic coastal shelf region. Specific to inorganic carbon and OA, the data available in the region has not been leveraged to conduct a comprehensive regional-scale analysis that would increase the ability to understand and model seasonal-scale, spatial-scale, and subsurface carbonate chemistry dynamics, variability, and drivers in the NES. This project optimizes the NES OA observation network encompassing the Mid-Atlantic and Gulf of Maine regions by adding seasonal deployments of underwater gliders equipped with transformative, newly developed and tested deep ISFET-based pH sensors and additional sensors (measuring temperature, salinity for total alkalinity and aragonite saturation [ΩArag] estimation, oxygen, and chlorophyll), optimizing existing regional sampling to enhance carbonate chemistry measurements in several key locations, and compiling and integrating existing OA assets. The researchers will apply these data to an existing NES ocean ecosystem/biogeochemical (BGC) model that resolves carbonate chemistry and its variability. 


Tuesday, March 3, 2020

Assessment of the Observing Network to Identify Processes Relevant to the Predictability of the Coastal Ocean of the Northeast on Centennial Time Scales

Samantha Siedlecki, University of Connecticut

Over the past 15 years, waters in the Gulf of Maine have taken up
CO2at a rate significantly slower than that observed in the open oceans due to a combination of
the extreme warming experienced in the region and an increased presence of well-buffered Gulf
Stream water. The reduced uptake of CO2 by the shelves could
also alter local acidification rate, which differ from the global rates. The intrusion of
anthropogenic CO2is not the only mechanism that can reduce Ωarag within coastal surface waters.
Local processes like freshwater delivery, eutrophication, water column metabolism, and
sediment interactions that drive variability on regional scales can also modify spatial variability
in Ωarag. Global projections cannot resolve these local processes with resolution of a degree
or more. Some high-resolution global projections have been developed which perform well in
some coastal settings . However, these simulations do not include regional
biogeochemical processes described above which can amplify or dampen these global changes,
particularly in coastal shelf regions. Our hypothesis is that a regionally downscaled projection
for the east coast of the US can be used to evaluate the ability of the existing observational
network to detect changes in ocean acidification relevant stressors for scallops and propose a
process-based strategy for the network moving forward.

Tuesday, March 3, 2020
Categories: Projects

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
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