Ecological Processes and Impacts Governing the Resilience and Alternations in the Porsangerfjord and the Hardangerfjord (EPIGRAPH)

The Porsangerfjord: The coastal cod population in the Porsangerfjord has been at a low level over the recent two decades and low recruitment has hampered recovery. The kelp forests, anticipated to be important nursery grounds for juvenile cod, has been er adicated over the recent three decades due to overgrazing by sea urchins. Currently the red king crap, a predator on sea urchins, is invading the fjord. Thus, the Porsangerfjord is a suitable model area for establishing and testing a range of hypotheses r elated to predation-controlled systems. An Ecopath model will integrate data on different trophic levels and serve as a tool to for testing various predation hypotheses. The Hardangerfjord: This ecosystem serves many functions: fisheries, aquaculture, re creation, tourism, resipient and transportation route. Recently, a number of changes have been observed in this ecosystem. The macroalgal vegetation, sprat, sea trout and wild salmon have declined dramatically. Both amount and seasonality of nutrients out lets to the fjord have changed. The Hardangerfjord is a suitable model area for formulating and testing hypotheses related to changes in oceanographic factors and subsequent effects on primary production, food webs and higher trophic levels. A modeling fr amework will be developed for this purpose.