Science Inventory

Factors influencing carbon stocks and accumulation rates in eelgrass meadows across New England, USA


Novak, A., M. Pelletier, Philip Colarusso, J. Simpson, N. Gutierrez, A. Arias-Ortiz, M. Charpentier, P. Masque, AND P. Vella. Factors influencing carbon stocks and accumulation rates in eelgrass meadows across New England, USA. Estuaries and Coasts. Estuarine Research Federation, Port Republic, MD, 43(8):2076–2091, (2020).


Seagrasses are valued habitats which are generally indicators of good estuarine water quality. Seagrasses are associated with diverse biological assemblages. They also alter hydrodynamics; seagrasses disperse wave energy and accumulate suspended material from the water column. Because of this, seagrass meadows are known to collect carbon in the sediments of their meadows (a process known as sequestration). The amount and rate of carbon sequestration is known to vary, and there is limited information for the northwest Atlantic. In this study we assessed 11 seagrass meadows between Maine and Rhode Island to determine how much carbon is sequestered in meadow sediments, as well as how quickly carbon is accumulated. We further determined that carbon sequestration is largely attributed to the size of sediment grains, nitrogen in sediments, and latitude. Data from this study will be used to inform New England States and Eastern Canada Provinces as they implement their Regional Climate Change Action Plan.


Increasing the protection of coastal vegetated ecosystems has been suggested as one strategy to compensate for increasing carbon dioxide (CO2) in the atmosphere as the capacity of these habitats to sequester and store carbon exceeds that of terrestrial habitats. Seagrasses are a group of foundation species that grow in shallow coastal and estuarine systems and have an exceptional ability to sequester and store large quantities of carbon in biomass and, particularly, in sediments. However, carbon stocks (Corg stocks) and carbon accumulation rates (Corg accumulation) in seagrass meadows are highly variable both spatially and temporally, making it difficult to extrapolate this strategy to areas where information is lacking. In this study, Corg stocks and Corg accumulation were determined at 11 eelgrass meadows across New England, representing a range of eutrophication and exposure conditions. In addition, the environmental factors and structural characteristics of meadows related to variation in Corg stocks were identified. The objectives were accomplished by assessing stable isotopes of δ13C and δ15N as well as %C and %N in plant tissues and sediments, measuring grain size and 210Pb of sediment cores, and through assessing site exposure. Variability in Corg stocks in seagrass meadows is well predicted using commonly measured environmental variables such as grain size distribution. This study allows incorporation of data and insights for the northwest Atlantic, where few studies on carbon sequestration by seagrasses have been conducted.

Record Details:

Product Published Date: 12/01/2020
Record Last Revised: 10/28/2020
OMB Category: Other
Record ID: 350016