Dataset: Compound specific isotope data of amino acids for abyssal macrofauna, megafauna, sediments, sediment traps, and in situ filtered particles at Station ALOHA off Hawaii and Station M off California from 2019 to 2020

Macrofauna and megafauna were collected in May and October 2019 using the HOV Alvin and the ROV Doc Ricketts, respectively, at Station M; and in July 2019, January 2020, and July 2020 using ROV Lu'ukai at Station Aloha. Macrofauna at Station M were collected using HOV-operated Ekman cores (20x20 centimeters (cm)). Macrofauna at Station Aloha were collected using a Brenke epibenthic sled towed across the seafloor due to the considerably lower macrofaunal densities at this oligotrophic site. Megafauna were collected using the submersible vehicle's manipulator arm and/or slurp gun. Upon retrieval to the surface, samples were placed in a cool room (5 degrees Celsius (ºC)) for further processing. Specimens of megafauna were weighed and measured, then they were dissected using a scalpel. All tissue samples were placed in cryovials and frozen in liquid nitrogen, and subsequently stored at -80ºC. Sieved (300 micrometers (um)) macrofauna samples were preserved in 10% buffered formalin. In the laboratory, macrofauna were further sorted by taxon. Samples of megafauna body tissues or macrofauna were freeze dried and ground to a homogenous powder using mortar and pestle.

Sediment samples were taken with ROV-operated push cores and sliced into 1 cm sections. Frozen samples were freeze dried, acidified, and then used for isotopic analysis. Sediment traps were McLane Parflux traps using formalin fixed collection cups varying from 10 to 30 day sample integration. Swimmers were removed from the samples under a dissecting microscope prior to concentration, freeze drying, and acidification for isotopic analysis.

Compound specific isotopic analysis of amino acids followed the protocols outlined in Hannides et al 2013.