Carbon Budget of Tidal Wetlands, Estuaries, and Shelf Waters of Eastern North America

Authors

RG Najjar
M Herrmann
R Alexander
EW Boyer
DJ Burdige
D ButmanFollow
W-J CaiFollow
Elizabeth A. Canuel, Virginia Institute of Marine ScienceFollow
RF ChenFollow
Marjorie A.M. Friedrichs, Virginia Institute of Marine ScienceFollow
et al

Document Type

Article

Department/Program

Virginia Institute of Marine Science

Publication Date

3-2018

Journal

Global Biogeochemical Cycles

Volume

32

Issue

3

First Page

389

Last Page

416

Abstract

Carbon cycling in the coastal zone affects global carbon budgets and is critical for understanding the urgent issues of hypoxia, acidification, and tidal wetland loss. However, there are no regional carbon budgets spanning the three main ecosystems in coastal waters: tidal wetlands, estuaries, and shelf waters. Here we construct such a budget for eastern North America using historical data, empirical models, remote sensing algorithms, and process‐based models. Considering the net fluxes of total carbon at the domain boundaries, 59 ± 12% (± 2 standard errors) of the carbon entering is from rivers and 41 ± 12% is from the atmosphere, while 80 ± 9% of the carbon leaving is exported to the open ocean and 20 ± 9% is buried. Net lateral carbon transfers between the three main ecosystem types are comparable to fluxes at the domain boundaries. Each ecosystem type contributes substantially to exchange with the atmosphere, with CO₂ uptake split evenly between tidal wetlands and shelf waters, and estuarine CO₂ outgassing offsetting half of the uptake. Similarly, burial is about equal in tidal wetlands and shelf waters, while estuaries play a smaller but still substantial role. The importance of tidal wetlands and estuaries in the overall budget is remarkable given that they, respectively, make up only 2.4 and 8.9% of the study domain area. This study shows that coastal carbon budgets should explicitly include tidal wetlands, estuaries, shelf waters, and the linkages between them; ignoring any of them may produce a biased picture of coastal carbon cycling.

DOI

10.1002/2017GB005790

Keywords

costal zone, ecosystems, estuarine environments

Recommended Citation

Najjar, RG; Herrmann, M; Alexander, R; Boyer, EW; Burdige, DJ; Butman, D; Cai, W-J; Canuel, Elizabeth A.; Chen, RF; Friedrichs, Marjorie A.M.; and et al, Carbon Budget of Tidal Wetlands, Estuaries, and Shelf Waters of Eastern North America (2018). Global Biogeochemical Cycles, 32(3), 389-416.

10.1002/2017GB005790