Dataset: Quadrat-based measurements of eelgrass shoot density and above-ground biomass for plants growing in shallow and deep zones at four coastal sites in Massachusetts, USA in 2019

Location description: Four coastal sites in the Gulf of Maine, USA, that sustain continuous eelgrass meadows across a depth gradient of ~1-2 m below MLLW to ~4-5.5 m below MLLW (see Supplemental File "Site List" for site codes used in this dataset and coordinates (lat,lon)).

We conducted a field survey in the shallow and deep zone of the meadow at each site, with zones defined by proximity to the respective edges of the eelgrass beds. Divers on SCUBA harvested all above-ground eelgrass biomass within in 5-7 0.25 x 0.25 m  quadrats set in each of three previously established permanent quadrats per depth per site (N = 15-21 quadrats per depth per site). Shoots were transferred to the lab on ice, where we counted the number of vegetative and flowering shoots in each sample; then we dried the plants at 60 degrees C and recorded aboveground biomass to the nearest milligram.  

Organism: 
eelgrass, Zostera marina, urn:lsid:marinespecies.org:taxname:495077