Abstract
Due to the growing need for raw material for fish feed production, there is an increasing pressure for extending harvest of zooplankton. At present there are fisheries for Calanus finmarchicus along the Norwegian coast and Antarctic krill (Euphausia super ba), but such fisheries are likely to be expanded in the near future. Zooplankton plays a key role in the ecosystem as both grazers and prey and thus acts as a link between the phytoplankton and planktivorous fish. Given the anticipated wish for an expans ion of zooplankton harvesting, it is important to start building up knowledge on how to assess the stocks and the effect such harvest may have on other parts of the ecosystem in general and on already harvested stocks in particular. The overall objectiv e of HALO is to quantify how harvest of lower trophic level organisms may affect ecosystem dynamics in the Norwegian Sea. The project will utilize an ecosystem model, NORWECOM.E2E, to assess the feasibility of harvesting species on lower trophic levels an d evaluate possible effects on higher trophic levels with special focus on already commercially exploited fish stocks. The NORWECOM model is spatial and allows for modelling both a spatially and temporal distributed fishery. It is therefore an ideal way o f studying possible geographical ecosystem effects of zooplankton harvest as well as evaluating periods where zooplankton harvest is particularly advantageous or disadvantageous. The model system will be extended with an mesopelagic fish module as well as a fishing vessel module.
Norway