Chesapeake Bay Acidification
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7.
What are the biological impacts of rising pCO2 and acidification in estuarine systems?
To date
there are relatively few
in-situ
experimental data related to biological responses to acidification in
Chesapeake Bay. Arnold et al. (2012) observed that submerged aquatic plants (Saint Mary’s and
Severn Rivers, MD) exposed to elevated CO
2,
grow substantially faster than under ambient
conditions. However, these sea grasses showed significant reductions in concentrations of many
carbon-based secondary compounds (e.g., phenolics) that serve as chemical armaments against
herbivory and disease. Laboratory experiments by Miller et al. (2009) conducted in mesohaline
conditions (18ppt) typical of Chesapeake Bay show that larvae of the native oyster (
Crassostrea
virginica
) experience strong reductions in growth and calcification under elevated CO
2
but that the
non-native congener species
Crassostrea ariakensis
showed no such reductions, suggesting
species-specific effects may be important in coastal systems. Studies by Ries et al. (2009) suggest
that calcification by blue crabs (
Callinectes sapidus
) and other crustaceans increases at high CO
2
levels. Breitburg and collaborators have been using a flow-through lab-based experimental
platform to investigate the combined effects of acidification and dissolved oxygen for species
found in Chesapeake Bay. Although, individual species response studies are common in
acidification research, few have investigated species assemblage/community level responses in
estuarine settings.
R
ECOMMENDATIONS
1.
The Chesapeake Bay Acidification Network (CBAN) should seek to understand both chemical and
biological effects of acidification dynamics, and aim to understand how long term trends in
atmospheric CO
2
concentration will affect the Bay’s ecosystems.
2.
Given the widespread ongoing research and monitoring taking place in Chesapeake Bay currently,
the opportunities for adding observations and measurements aimed at characterizing the carbonate
system dynamics and the underlying mechanistic drivers of carbonate chemistry as it relates to
coastal acidification are extensive. Such efforts could leverage the Bay’s existing infrastructure
and monitoring programs (e.g., existing water quality stations, water quality and oceanographic
cruises), thereby rapidly increasing our knowledge about coastal acidification at regional and local
scales. MD-DNR’s “Eyes on the Bay Program” is a good example of an observing network that
could be supplemented to begin collecting carbonate chemistry data.
3.
Amass descriptions of Chesapeake Bay’s water quality research programs, monitoring networks
and infrastructure that can be leveraged for carbon chemistry observations. This should include
measurement and observation platforms such as buoys, piers, land-based water quality stations,
ship and boat cruise locations and frequency. The goal is to identify the most promising
opportunities to collect new high quality data.
4.
A list of investigators and laboratories from the Chesapeake Bay region with expertise in carbon
chemistry analyses (e.g., pCO
2
, Total CO
2
, Total Alkalinity, and pH) should be collected to assess
the region’s current capacity to make high quality carbon measurements, to determine the need to
develop local and regional expertise, and to promote collaborations with investigators from other
regions.
5.
Research efforts should be focused on understanding and quantifying the flux of inorganic carbon
across the ecological subsystems of the Bay watershed that affect acidity in the Bay (e.g.,
land:bay, ocean:bay, sediment:bay). Cross-boundary fluxes will have strong effects on water
chemistry at local, ecologically relevant scales.
