Conversion factors for Greenland shelf benthos: Weight-to-weight and body-size-to-weight relationships

Abstract. Climate change, biodiversity loss and increasing human activity are rapidly transforming Arctic marine ecosystems. Benthic ecosystems on Arctic shelves are important for biodiversity and ecosystem functioning. Biomass in the form of ash-free dry mass (AFDM) is often used as a proxy of ecosystem health but can be labour intensive and costly to obtain. This study addresses a key data gap by providing robust weight-to-weight and body-size-to-weight conversion factors for Arctic and boreal benthic fauna. We collected samples of common macro- and mega-benthic organisms in SE Greenland (59–67° N and 27–41° W) and calculated conversion factors (slopes) based on the relationship between wet mass (WM) to dry mass (DM) (33 families), WM to AFDM (31 families) and DM to AFDM (35 families) (https://doi.org/10.5281/zenodo.19346004, Behrisch and Zwerschke, 2026). To improve sampling output from non-destructive image-based sampling we also calculated conversion factors between body-size (length, diameter) and weight for a subset of families (Behrisch and Zwerschke, 2026). Our dataset includes several Vulnerable Marine Ecosystem (VME) indicator taxa for the Arctic region. The conversion factors for Atlantic-Arctic benthos presented here can serve as the foundation for a growing database, helping to unify datasets collected using different methodologies.