The Red King Crab Paralithodes camchaticus (Tilesius, 1815) (DECAPODA: ANOMURA): The Use of Species Equality Indicators to Assess the Influence on the Benthos of the Barents Sea

The Difference of Evenness (D-E) index, based on the ratio of r- and K-strategists in benthic communities was proposed for a quick assessment of the ecological consequences of the introduction of the red king crab Paralithodes camtschaticus (Tilesius, 1815) from Kamchatka in the Barents Sea. It was found that the red king crab, which selectively eats medium-sized invertebrates, changes the size-age composition of the soft-bottom benthos towards the predominance of juveniles of long-lived species, which is equivalent to the abundance of small opportunistic species. The D-E index values obtained for the coastal area of the Barents Sea at a settlement density of the king crab of 20 ind./1000 m(2) or more indicated ecological stress to benthic communities of soft soils, that is, a change in the size composition and the degree of species dominance in terms of biomass.

Automated summary

The introduction of the red king crab from Kamchatka in the Barents Sea has led to changes in the size-age composition of benthic communities, with ecological stress observed when the settlement density reaches 20 ind./1000 m(2) or more. This results in a shift in the size composition and species dominance in terms of biomass in the affected area.