Blue carbon potential of eelgrass in the Puget Sound

Abstract

Coastal ecosystems sequester and store large amounts of carbon making them important contributors to the global carbon budget. There are growing efforts to quantify this coastal marine carbon, referred to as blue carbon, in different regions of the world. Due to the diversity of species and habitats worldwide, and to high spatial variability in carbon storage capacity, local estimates yield the best measures of stored carbon. In this study we estimate the blue carbon potential of eelgrass ecosystems in the Puget Sound, WA, USA. Although direct measures of sediment carbon in seagrass beds are mostly unavailable for the Puget Sound, we used carbon storage values from Padilla Bay, the region with the largest eelgrass extent, and extrapolated carbon storage capacity of Puget Sound eelgrass beds. Our analysis suggests that eelgrass beds in Puget Sound sequester carbon at a rate of 4.2 ± 1.9 ktC yr-1 and store 1819 ± 239 ktC of carbon in the sediment. The uncertainties associated with these estimates can be reduced through location-specific studies of the effects of depth, eutrophication, and sedimentation on carbon burial and storage