14. Nov 2019

Recent observations and fisheries landings statistics have shown native crab species expanding their spatial distribution and density northwards through Nordland and into Troms counties, presumably as a result of climate change. Recent studies indicate that increasing predation by these mesopredators on sea urchins contributes to regime shifts from sea urchin barrens to kelp recovery. The aim of this project will focus on possible effects of predation by the northwards expanding Cancer pagurus and Carcinus maenas on fauna composition in shallow benthic habitats, and on community composition in recently recovered kelp forests. This will be tested through aquarium experiments, field sampling and stomach analysis of crabs. By sampling in different habitats and in areas of different densities of crabs and different intensities of crab fishery, we will gain knowledge of the crabs effect on ecosystem functioning and how human activity may affect functional diversity in shallow benthic ecosystems. Data sharing and collaboration with environmental economists in MIKON flagship project MULTIHARVEST will elucidate ecosystem services and value of both crab fishery and ecological conditions.