Seagrass sediments as a global carbon sink: Isotopic constraints

TLDR: In this article, the authors provided a comprehensivesynthesis of available data to obtain a better understanding of the relative contribution of seagrass and other possible sources of organic matter that accumulate in the sediment of the seafloor seagranthus meadows.

Abstract: Seagrass meadows are highly productive habitats found along many of the world’scoastline, providing important services that support the overall functioning of the coastalzone. The organic carbon that accumulates in seagrass meadows is derived not only fromseagrass production but from the trapping of other particles, as the seagrass canopiesfacilitate sedimentation and reduce resuspension. Here we provide a comprehensivesynthesis of the available data to obtain a better understanding of the relative contributionof seagrass and other possible sources of organic matter that accumulate in the sedimentsof seagrass meadows. The data set includes 219 paired analyses of the carbon isotopiccomposition of seagrass leaves and sediments from 207 seagrass sites at 88 locationsworldwide. Using a three source mixing model and literature values for putative sources,we calculate that the average proportional contribution of seagrass to the surfacesediment organic carbon pool is ∼50%. When using the best available estimates ofcarbon burial rates in seagrass meadows, our data indicate that between 41 and66 gC m