This dataset contains ecosystem metabolism and seagrass meadow data from five locations in the Greater Caribbean and Gulf of Mexico regions at which green turtle populations had established foraging areas. Ecosystem metabolic rates were compared between grazed and adjacent ungrazed areas of seagrass (Thalassia testudinum) to investigate the effects of green turtle grazing on metabolic carbon capture rates in seagrass meadows across a wide geographic area. Seagrass data are provided for site descriptions and drivers of variation in metabolic rates. Ecosystem metabolic rates are also included for meadows of the invasive seagrass Halophila stipulacea from two locations for comparison to rates in the native seagrass meadows where this invasive seagrass is encroaching upon green turtle foraging areas. Data were collected from one location (Little Cayman) in 2016, and from the remaining four locations (Bonaire; St. Croix; Eleuthera, Bahamas; west coast of Florida) in 2018.