Acronym NA
Category
Fisheries
Title The fundamental role of mesopelagic fishes for the structure and change of Northeast Atlantic marine ecosystems Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Christian Jørgensen Coordinator email christian.jorgensen@uib.no
Coordinator institution
UiB - University of Bergen (Norway)
Institutions involved
NA
Start year 2019 End year 2024 Funding (€) € 1,025,125 Website https://prosjektbanken.forskningsradet.no/en/project/FORISS/294819?Kilde=FORISS&distribution=Ar&chart=bar&calcType=funding&Sprak=no&sortBy=date&sortOrder=desc&resultCount=30&offset=0&Prosjektleder=Christian+J%C3%B8rgensen Summary We aim to show that mesopelagic fishes are a key player that structures fundamental characteristics of the Norwegian Sea ecosystem. Mesopelagic fishes are only a few cm long, live at depths down to ca thousand meters and migrate vertically towards the surface to feed on zooplankton during night. They are extremely abundant and found everywhere in the world’s oceans but with declining biomass towards the poles. We have preliminary models showing that the northward distribution of mesopelagic fishes is constrained by seasonality: in summer because the midnight sun means there is no night during which they can migrate safely to the surface to feed, and in winter because especially juveniles may starve during the polar night with its low productivity. This is of significance because what is elsewhere a major predator on zooplankton from below leaves a planktivore niche vacant at high latitudes. This niche has become occupied by schooling and horizontally migrating fish species such as herring, mackerel, and capelin, which are among the largest fished stocks in the world and of significant commercial value. Furthermore, we hypothesize that the lack of predation from mesopelagic fish on overwintering stages of zooplankton enable multi-year life cycles for Arctic copepods such as Calanus glacialis and C. hyperboreus. These form large visible targets and are an attractive resource for planktivorous fish. Finally, the models suggest that ocean warming will affect the northern range limits of mesopelagic fish opposite to what is expected from conventional climate envelope models: increased metabolic rates will make mesopelagic fish struggle more with both midnight sun and polar night. Consequently, we expect equatorward shifts of the northern range boundaries. Any alteration of mesopelagic biogeography has the potential to cause large-scale changes in competitive relationships in the Norwegian Sea, with consequences for herring, mackerel, and the rest of the food chain.
Keywords
Food web;
Fish;
Climate change;
Impacts;
Marine Region
41
Norwegian Sea (27.IIa)
1
Marine Region Map
