H-Print and Sympagic carbon estimates in pelagic particulate organic matter (POM), sediments and benthos in the fjords and on the shelf of Northeast Greenland in August to September 2022

Highly branched isoprenoids (HBIs) are diatom-produced lipids which are used as biomarkers to track pelagic and sympagic (ice-associated) carbon in the Arctic environment. HBIs were measured in pelagic particulate organic matter (POM), sediment and faunal samples collected aboard the R/V Kronprins Haakon on the Northeast Greenland shelf, in August and September 2022 as part of the UiT-led TUNU programme. HBIs were extracted and then measured with a Shimadzu QP-2020 GC-MS. An internal standard was added to each sample prior to extraction to confirm appropriate extraction. HBI spectral intensities were used to calculate the H-Print, a ratio of 3 target HBIs. For faunal samples, the H-Print was used to calculate the proportion of carbon assimilated by fauna which originated from sympagic production.