Freeze-dried core tops from 8 stations between 900 and 3000 m for sedimentary organic matter, and punches from 0.7 µm GFF filters for suspended particulate organic matter, were decalcified with 2N HCl, washed, freeze-dried, and subjected to analysis via a Flash EA 1112 Series (Thermo Scientific) analyser, coupled via a Conflo II interface to a Finnigan Delta^plus^ mass spectrometer as described by Lengger et al. (2014; sediment) and Pitcher et al. (2011; doi:10.1038/ismej.2011.60; filters). Standards for δ^13^C analysis were acetanilide and benzoic acid and samples were analysed in duplicate.