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The study addresses how local abiotic variability links zooplankton stocks to climate systems. Four zooplankton species and abiotic environmental data were sampled annually during October and February 1983-2005 in two northern Norwegian fjord basins. Inter-decadal change in abundance occurred in both fjords but differed between the two communities, presumably resulting from combinations of topography, specific life history strategies and preference for ambient water qualities before advective migration into the habitats. The shallow Mistfjord sill led to accumulation of coastal water in the fjord basin, while the deeper Saltfjord sill allowed frequent seasonal exchange of Atlantic basin water. Changes in basin water temperature and salinity were decadal in the Mistfjord basin, and inter-annual in the Saltfjord basin. Several biotic and abiotic variables covaried with climate indices, which indicates causal relationships between hemispheric climate variability and abundance of wintering zooplankton, but the processes involved are not fully understood. North Atlantic Oscillation apparently forced vernal freshwater discharge from Norway, summer reproduction in neritic waters and geographic distribution of basin-scale population systems. Stratospheric forcing as indicated by Arctic Oscillation seems to be involved in geophysical relationships which influence dynamic processes in zooplankton population systems within the Arctic Mediterranean. arctic regions of the Atlantic sector. NAO above the long-term average (positive NAO) generates southwesterly winds towards Scandinavia (Hurrell, 1995) which discharges latent heat and precipitation over Norwegian coastal landscapes while NAO below average (negative NAO) is associated with dryer climate. Seasonal accumulation of snow and vernal meltwater runoff causes large river discharge in May-July (Tollan, 1976) which generates pronounced geophysical changes in coastal recipients (Saetre, 2007). Several authors have discussed how natural freshwater discharge and lowered salinity during summer may influence neritic biological production (Helland-Hansen

Zooplankton sampling in 1997 identified the frontal zone of the Norwegian Coastal Current as a reproduction habitat for Calanus finmarchicus in June–August. This area is subject to considerable ultraviolet radiation (UVR), as calculated from satellite observations of ozone and cloudiness. While in situ experiments indicated UVR-induced mortality in reproducing C. finmarchicus, monthly UVR doses during the actual reproduction period did not appear to affect the abundance of the resulting generation of adolescent copepodites (CIV-V) that accumulated in a fjord habitat during October 1983–2000. Local UVR in the spawning grounds of Arcto-Norwegian cod at the Lofoten Islands in March–May was positively correlated with the stock's 0-group index, which resulted in the rejection of the hypothesis that local UVR leads to high mortality of cod eggs or reduces the abundance of prey for cod larvae. Rather, the result suggests an indirect positive effect of UVR on the survival of cod eggs and larvae, possibly by controlling harmful microbes.