Reduced size composition and fecundity related to fishery and invasion history in the introduced red king crab (Paralithodes camtschaticus) in Norwegian waters

The introduced red king crab (Paralithodes camtschaticus) in the Barents Sea is abundant in the coastal waters of eastern Finnmark and supports a valuable fishery. In this paper we look at the development in size span among ovigerous females in the period between 1995 and 2010. We identify variations in individual fecundity in three fjords in Finnmark from 2000 to 2007. All the analyses were performed using regression and general linear models. We found that the size range decreased during this period. A decline in individual fecundity was observed. Individual egg weight (IEW) varied among fjords and years, and displayed a tendency to decline during the period of investigation, but the IEW was not affected by crab size. Increased fishing pressure on large males may have caused both a decline in size range of ovigerous females as well as a decline in fecundity. Reduced IEW however is likely to be due to limited available food. We attempted to compare individual fecundity in the invasive crab with fecundity results from populations in native areas. This comparison was inconclusive, due to differences in sampling season, size range and the methods employed.