Sponges were sampled from multiple sites in the Northeast Atlantic from multiple cruises aboard the CCGS Amundsen. Benthic sponges were obtained through Box cores, Agassiz trawls, and through targeted sampling using the SuMO ROV. Sponges were photographed on board and in-situ when possible (using ROV camera). Collected sponges were retained for taxonomic analysis. Whole or portions of each collected sponge were preserved in 96% ethanol to prevent DNA degradation. Larger sponge fragments were frozen on board. Collected sponges are to be subsampled for morphology-based taxonomy (analysis of spicule structure and body form), and for molecular taxonomy through extraction and amplification of cytochrome oxidase subunit I (COI) mitochondrial DNA fragments for DNA barcoding. In total, 112 separate sponges were sampled during the 2015/2016 leg from depths ranging between 80-1148 metres and encompassing latitudes 60°18N to 68°15N. 31 specimens were collected using the ROV and therefore have associated in-situ video imagery which will aid in species identifications and descriptions. In total, 48 separate sponges were sampled during the 2017 leg from depths between 84 - 875 metres and encompassing latitudes 62°34N to 78°19N. Nine specimens were collected using the ROV and therefore have associated in-situ video imagery which will aid in species identifications and descriptions. In-situ videos are not included in the dataset but will be made available upon request. See Links to data section for contact.

Agassiz trawl was deployed from the CCGS Amundsen to collect macrofauna. Catches were passed through a 2 mm mesh sieve. When possible, specimens were identified to the lowest taxonomic level, then count and weight. The unidentified specimens were preserved in a 4% seawater-formalin solution. Box corer was deployed to quantitatively sample diversity, abundance and biomass of infauna and to sample sediment. Sediments of a surface area of 0.125 m2 and 10-15 cm in depth were collected and sieved through a 0.5 mm mesh and preserved in a 4% formaldehyde solution for further identification in the laboratory. Sub-cores of sediments were collected for sediment pigment content, organic matter, sediment grain size, porosity; for sediment pigments, the top 1 cm was collected, although for sediment grain size, the top 5 cm was collected. Sediment pigment samples were frozen at -80°C, and porosity, organic matter and sediment grain size samples were frozen at -20°C.