Comparative analysis of Calanus finmarchicus demography at locations around the Northeast Atlantic

Standardized time-series sampling was carried out throughout 1997 at seven locations around the Northeast Atlantic to investigate regional variations in the seasonal demography of Calanus finmarchicus. Sites ranged from an inshore location in the North Sea, where C. finmarchicus formed only a small component of the zooplankton (2000 mgC m-2 during spring and summer). The internal consistency of the demographic time-series from each site was investigated by three partial models of life-cycle processes. In general, the demography of late copepodites could be accounted for by a relatively simple forecast model of stage development and diapause. However, there was a large discrepancy between nowcast estimates of egg production based on female abundance, temperature, and chlorophyll, and hindcast simulations of the egg production required to account for the observed abundance of early copepodite stages. The results point to a gap in our understanding of seasonal variations in rates of egg production and/or survival of nauplii. Overall, the population sampled at Weathership M appeared to be reasonably self-contained, but all other sites were reliant on invasion of overwintered stock in spring. At least two generations were observed at all but one site, but the extent to which these were generated by discrete bursts of egg production varied between sites and seemed to be partly dependent on the proximity to an overwintering location

Programme to assess the ecological effects of oil spills in coastal areas of Norway

The basic biological effects of oil spillage on coastal ecosystems is quite well documented following the Torrey Canyon and the Santa Barbara, California spills. Both these areas can be expected to be quite different biologically from the Norwegian coasts. The Torrey Canyon oil affected areas of Britain and Brittany are characterised by large tidal ranges and rapid tidal currents, whilst the Pacific coast of the U.S.A. has considerably different ecosystems. Thus although the experience of the above cited spills can be used the biological effects will need to be monitored anew in Norway. The following plan draws on the reports of the above two disasters