Biomass of Ophiuroidea и Echinarachnius parma on a plot of the West Kamchatka shelf in 2013–2017

Abstract

According to the results of bottom grab surveys carried out in 2013–2016, data on the biomass (g/m2) of the dominant sea urchin species Echinarachnius parma and the complex of brittle stars on a plot of the West Kamchatka shelf are given. The average biomass of Echinarachnius parma for the surveyed plot varied over the years and in 2013 was 45.298 ± 25.582 g/m2, in 2014 – 48.784 ± 26.561 g/m2, in 2015 – 19.557 ± 11.678 g/m2, in 2016 – 18.957 ± 13.192 g/m2. In terms of biomass on the surveyed plot (g/m2) the main role among the echinoderms belongs to fl at sand dollars, and in terms of population density (ind./m2) – to brittle stars. 11 species of brittle stars from 4 families were noted. In terms of population density the most common species among the brittle stars are Amphiodia craterodmeta and Ophiura quadrispina.