Carbon budget of tidal wetlands, estuaries, and shelf waters of eastern North America

Global Biogeochemical Cycles
By: , and 

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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 CO2uptake split evenly between tidal wetlands and shelf waters, and estuarine CO2outgassing 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.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Carbon budget of tidal wetlands, estuaries, and shelf waters of eastern North America
Series title Global Biogeochemical Cycles
DOI 10.1002/2017GB005790
Volume 32
Issue 3
Year Published 2018
Language English
Publisher AGU
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 28 p.
First page 389
Last page 416
Country United States