Chesapeake Bay Acidification
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combinations of carbonate system parameters will yield the most robust data for an estuarine system?
What are the specific biological impacts of acidification should CBAN be designed to detect, and how do
these impacts influence socioeconomic conditions in the Chesapeake Bay region?
I
NTRODUCTION
Chesapeake Bay is arguably the most intensively studied estuary in the world. Indeed, much of our
understanding of basic estuarine chemistry, hydrodynamics, ecology, and fisheries can be attributed to
research carried out in this ecosystem. Chesapeake Bay continues to be studied extensively across many
dimensions, yet little attention has been paid to carbonate chemistry dynamics and drivers, information
that is critical as we seek to make projections about how the Bay ecosystem, and other estuaries, will be
affected by elevated atmospheric carbon dioxide (CO
2
) in coming decades. Despite this dearth of
information, Chesapeake Bay is an excellent model system for understanding complex coastal
acidification processes. The combined scientific and environmental monitoring activities and
infrastructure overseen by state and federal agencies, as well as academic institutions, and non-
governmental organizations, provide a vast number of observing platforms and opportunities (shore-
based, vessel-based, and buoy-based) with the potential for advancing carbonate chemistry measurements.
Given the sheer number of researchers who currently focus their efforts on various aspects of Chesapeake
Bay and its watershed, the prospects for developing acidification-based collaborations are expansive and
promising.
The combustion of fossil fuels during the past 200 years has resulted in a significant increase in
atmospheric CO
2
from approximately pre-industrial levels of 280 parts per million by volume (ppmv) to
the current global average of ~400 (IPCC AR5 2013). Projections of fossil fuel use suggest atmospheric
concentrations are likely to rise significantly (doubling or more) in the next 100 years and that we are
experiencing CO
2
input to the atmosphere that is unprecedented (Hönisch et al., 2012). Since 1800,
surface ocean pH has decreased ~0.1 units, and further reductions of 0.1 to 0.4 units are anticipated due to
rising CO
2
(Doney et al., 2009; Caldeira & Wickett, 2003, 2005; Orr et al., 2005). There is widespread
concern that these changes will produce irreversible ecological regime shifts in marine habitats, such as
massive reductions in coral reef habitats and inhibition of other calcifying biota.
However, current predictions regarding the effects of elevated atmospheric CO
2
are driven almost
exclusively by the open ocean assumption of an air-water equilibrium, regardless of geographic or
oceanographic setting. Such assumptions do not hold in coastal marine habitats, which are influenced
significantly by terrestrial and near-shore phenomena, including significant biological perturbation to the
water’s carbonate chemistry. To explore the complex nature of acidification processes and mechanisms,
carbonate chemistry dynamics, and potential environmental and ecological impacts, the Integrated Ocean
Observing System (IOOS) funded the Alliance for Coastal Technologies (ACT) to organize a workshop
focused on acidification in Chesapeake Bay.
A workshop was convened on March 11-13, 2014 to explore the current scientific knowledge and critical
information gaps related to carbonate chemistry dynamics, processes, and mechanisms that ultimately
determine the pH environment of Chesapeake Bay. In particular, the workshop focused on how elevated
atmospheric CO
2
may affect coastal marine and estuarine waters, with a specific focus on Chesapeake
Bay, recognizing that the air:sea interface is but one of several important biogeochemical boundaries that
affect carbon dynamics in this and many other estuaries and coastal marine ecosystems. Ultimately, the
goal of the workshop was to evaluate the state of the science as it relates to coastal ocean acidification and
to begin amassing information on current monitoring assets, data sources, and data gaps as they relate to
measuring and monitoring carbonate chemistry, with an eye toward designing a Chesapeake Bay
