Whereas Arctic benthic decapods are not a species-rich group, they can dominate the local epifauna and play important roles
in the ecosystem. We studied the decapod fauna from Isfjorden (Svalbard, Norway, 78°N) by sampling from 22 stations and comparing
with 50 and 100-year-old data from the same localities. Our data provide no evidence of changes in the species composition
of decapods during the last 50 years. Hence, we do not observe the poleward shift of species found in several pelagic communities
in the North Atlantic. However, there is statistical evidence for changes in the community structure between 1908 and both
1958 and 2007. The main change is a shift towards communities more dominated by the spider crab
Hyas araneus and the hermit crab
Pagurus pubescens in 2007, and with a corresponding decrease in the two shrimp species
Lebbeus polaris and
Spirontocaris spinus. These shrimps are specialist predators compared to the more opportunistic, scavenging crabs. We argue that increased disturbance
levels may be a causal factor behind the observed community change, with likely sources of disturbance including trawling
and climatic fluctuations.
Keywords Arctic - Benthos - Biodiversity - Century - Climate - Community - Decapoda - Oceanography - Time series