A generalised volumetric method to estimate the biomass of photographically surveyed benthic megafauna

Data for paper: A generalised volumetric method to estimate the biomass of photographically surveyed benthic megafauna (https://doi.org/10.1016/j.pocean.2019.102188) (1) Individual body-size data (M, biomass; V, biovolume) of trawl-caught megabenthic invertebrates and demersal fish at the Porcupine Abyssal Plain Sustained Observatory (PAP-SO, NE Atlantic, 4850 m water depth), as directly (Mm, Vm) and indirectly (Me, Ve) measured. (2) Individual body-size data (M, biomass; V, biovolume) of photographically surveyed megabenthic invertebrates and demersal fish at three shelf-sea locations in the Celtic Sea (NE Atlantic, 100 m water depth), as indirectly (Me, Ve) measured. (3) Inter-operator variation assessment of individual body-size data as indirectly measured. A traditional length-weight relationship (LWR) approach was employed to estimate individual biomass (Me), a the proposed generalised volumetric method (GVM) was used to estimate individual biovolume (Ve).