Isotopes and content of carbon, nitrogen, and sulfur of eelgrass (Zostera marina) from West Falmouth Harbor from 2005 through 2019

West Falmouth Harbor (West Falmouth, MA, USA) has been experiencing a dramatic increase in nitrogen loading from an upgradient municipal wastewater treatment facility since the early 2000’s. As part of a long-term study into the effects of this nitrogen enrichment, we have been assessing changes in the extent and health of the eelgrass (Zostera marina) community within the harbor. Eelgrass shoots were collected during the summer and run for carbon (C), nitrogen (N), and sulfur (S) content and isotopic composition. Samples were analyzed from 7 stations in the more well-flushed outer harbor (OH), 4 stations in the middle of the harbor (MH), and 6 stations in the inner portion of the harbor in close proximity to a high groundwater nitrate source (Snug Harbor, SH). Carbon data is available from 2011 through 2018, nitrogen data from 2006 through 2018, and sulfur data from 2005 through 2019 with a few samples from 2021. Sulfur results have been published in Haviland et al. 2022 (doi: 10.1002/lno.12025).