Does scyphozoan jellyfish, Cyanea capillata, limit habitat for the Barents Sea species during the late feeding period

Data over a period 1993–2013 were used to explore the following questions: Does scyphozoan jellyfish limit habitat for the Barents Sea species during the late feeding period. The area of high concentration of both studied species and jellyfish and area free for high jellyfish concentration were estimated and response of jellyfish overlap on krill/fish was tested by GAM. The area of co-occurrence of high fish/krill and jellyfish densities were positive correlated with species biomass indices/estimates (0-gr capelin, 0-gr herring, capelin (age 1-2), young herring and blue whiting, indicating that higher densities of jellyfish not necessarily limit fish aggregations. At the same time larger area free for high amount of jellyfish were associated with larger 0-gr capelin, 0-gr cod, capelin (1-2) and young herring indices/estimates. In years with low jellyfish indices, jellyfish has no effect on fish/krill densities, while in other years fish/krill were low with low jellyfish, increased with increased jellyfish densities, and fall with very high jellyfish densities. This most likely indicated that very high jellyfish densities have potential to limit 0-gr cod, 0-gr haddock and 0-gr polar cod habitat. However, co-occurrence of high densities of both jellyfish and fish/krill indicated most likely a high productive area.