Abundances and isotopic data of inventoried species within tubeworm assemblages of the hydrothermal edifice Grotto (Main Endeavour Field, Juan de Fuca Ridge), during the oceanographic cruises Ocean Networks Canada's Expedition 2015 and 2016: Wiring the Abyss. Six sampling units were collected to represent variate stages of ecological succession on the edifice. Details on the sampling method and analyses are published in Lelièvre et al. 2018 (https://doi.org/10.5194/bg-15-2629-2018).