Table 1.

Site characteristics. Sites are arranged from north to south. Relative exposure is based on the amount of enclosure at the site and fetch at eelgrass sites. Tidal ranges were obtained from NOAA datums (https://tidesandcurrents.noaa.gov/stations.html?type=Datums). The average salinity and range (in brackets) were obtained from the US EPA’s National Coastal Assessment Program (http://www.epa.gov/emap). Substrate is the median grain size from the top 5 cm of the meadow sediment cores from this study, summarized as the appropriate Wentworth class

Site	Latitude (dd)	Longitude (dd)	Relative exposure	Tidal range (m)	%Nitrogen in eelgrass	Salinity (psu)	Substrate
Portland, ME	43.67	− 70.24	Moderate	2.78–3.02	2.44	30.8(29.0–31.7)	Very fine sand
Great Bay, NH	43.07	− 70.88	Moderate	2.05–2.25	1.74	25.9(16.5–30.9)	Silt
Gloucester, MA	42.60	− 70.66	Low	2.68–2.92	1.13	31.6(30.1–33.6)	Medium sand
Nahant, MA	42.42	− 70.92	Moderate	2.89–3.13	1.08	31 (30.2–31.4)	Fine sand
Boston Harbor, MA	42.33	− 70.96	Moderate	2.89–3.13	1.56	30.3 (24.6–32.9)	Very fine sand
Cohasset, MA	42.25	− 70.78	High	2.89–3.13	1.18	30.3 (29.8–30.8)	Fine sand
Orleans, MA	41.75	− 69.95	Low	1.20–1.40	1.32	30.7(30.2–31.5)	Very fine sand
W. Falmouth, MA	41.61	− 70.65	Low	0.55–0.67	0.93	30.1 (29.5–31.0	Medium sand
Prudence Island, RI	41.58	− 71.32	High	1.14–1.26	1.71	30.4 (19.5–32.9)	Medium sand
Martha’s Vineyard, MA	41.46	− 70.60	Moderate	0.85–0.95	0.97	28.7(18.1–31.8)	Fine sand
Charlestown, RI	41.37	− 71.64	Low	0.77–0.88	1.16	29.6 (26.0–32.3)	Silt