| |
| |
|
|
|
|
| |
 |
Biogeochemical processes in land-ocean interfaces, surface estuaries, subterranean estuaries and sediment-water interface
|
| |
|
|
Insights from spatial distributions of inorganic carbon parameters in the Chesapeake Bay: a bay-wide buffering mechanism via carbonate mineral precipitation and dissolution
Monday 7th @ 1330-1350, Conference Room 1
Weijun Cai* , University of Delaware
Jean Broedeur, University of Delaware
Jianzhong Su, University of Delaware
Baoshan Chen, University of Delaware
Najid Hussian, University of Delaware
Presenter Email: weijun.cai@gmail.com |
| We present results from a comprehensive study of inorganic carbon parameters along the main stem Chesapeake Bay, allowing evaluation of the carbonate system behaviors and coastal acidification status in this large, urban, eutrophic, and coastal plain estuary. Ten cruises were conducted from March to December, 2016, and samples of pH, dissolved inorganic carbon (DIC), total alkalinity (TA) and calcium concentration were analyzed in order to describe spatial and seasonal patterns. DIC was removed due to strong biological production in the surface and enriched due to both aerobic and anaerobic respiration and carbonate dissolution in subsurface. A DIC mass balance analysis reveals that the Chesapeake Bay is a net CO2 sink and is net autotrophic, in great contrast to the paradigm that globally most estuaries are CO2 sources and net heterotrophic.
In contrast to other estuarine studies where alkalinity is largely conservative, alkalinity was frequently non-conservative in the Chesapeake Bay, with large removals in the upper bay and releases in the subsurface of the mid- and lower bays. The recovery of submerged aquatic vegetation (SAV) across the Susquehanna Flats in the upper bay where very high pH conditions have promoted the precipitation of calcium carbonate may provide an important buffering resource via transport of the minerals to the low pH mid- and lower bays. This mechanism provides a bay wide shelf-regulated acid-buffering mechanism in response to eutrophication and acidification.
|
|
|
|
|
|
|
|
|