Dataset: Carbonate rock species composition from samples collected by HOV Alvin during R/V Atlantis cruises AT37-13 and AT42-03 and ROV SuBastian during R/V Falkor cruise FK190106 at Pacific margin of Costa Rica from 2017 to 2019

In situ carbonate rocks were taken at sites with different seepage activity in 2017 (AT37-13) and 2018 (AT42-03) using HOV Alvin and in 2019 using ROV SuBastian. These were used as control samples for the following experiments: (1) Colonization experiment: Carbonate rocks deployed for 3 months (Oct. 2018- Jan. 2019) and 17 months (Jun. 2017-Oct. 2018) at different seepage activity, (2) Transplant experiment: Carbonate rocks with attached fauna were moved by the HOV to different seepage conditions with exposure for 17 months (Jun. 2017-Oct. 2018).

All substrates were photographed intact upon recovery, and wrapped in aluminum foil to determine the surface area. Photographs were kept for reference. Before preserving, the sample was kept cold and animals were picked to sample tissue for isotope analysis (see related dataset for isotopic data).

The remaining sample was sieved through 0.3 mm mesh, separating the sample in two fractions (a fine fraction with the meiofauna, and a coarser one with the macrofauna), both preserved in 96% Ethanol.