An annual profile of the impacts of simulated oil spills on the Northeast Arctic cod and haddock fisheries.

We simulate the combined natural and pollutant-induced survival of early life stages of NEA cod and haddock, and the impact on the adult populations in response to the time of a major oil spill in a single year. Our simulations reveal how dynamic ocean processes, controlling both oil transport and fate and the frequency of interactions of oil with drifting fish eggs and larvae, mediate the magnitude of population losses due to an oil spill. The largest impacts on fish early life stages occurred for spills initiated in Feb-Mar, concomitant with the initial rise in marine productivity and the earliest phase of the spawning season. The reproductive health of the adult fish populations was maintained in all scenarios. The study demonstrates the application of a simulation system that provides managers with information for the planning of development activities and for the protection of fisheries resources from potential impacts.

Simulating crude oil exposure, uptake and effects in North Atlantic Calanus finmarchicus populations.

A simulation model framework (SYMBIOSES) that includes a 3-dimensional ocean physics and biology model and a model for transport and fate of oil was used to investigate the potential for bioaccumulation and lethal/sublethal effects of oil components in the copepod Calanus finmarchicus in the Lofoten-Vesterålen archipelago of Norway. The oil model is coupled with the biology model by way of a bioaccumulation model, from which mortality and reduction in reproduction are calculated via a total body burden (TBB). The simulation results indicate that copepod body burden levels are affected by the spill type (surface spill, subsea blowout) and the spill timing (spring, autumn). The effects of oil component bioaccumulation on the copepod population for all scenarios are small, though greatest in the subsea blowout scenarios. We attribute this to the limited spatial and temporal overlap between copepods and oil in the environment simulated by the model. The coupling of the processes of oil transport, bioaccumulation/excretion and the associated effects are discussed in the context of the model framework and with a view towards applications for Ecological Risk Assessment (ERA).

Assessing impacts of simulated oil spills on the Northeast Arctic cod fishery.

We simulate oil spills of 1500 and 4500m3/day lasting 14, 45, and 90days in the spawning grounds of the commercial fish species, Northeast Arctic cod. Modeling the life history of individual fish eggs and larvae, we predict deviations from the historical pattern of recruitment to the adult population due to toxic oil exposures. Reductions in survival for pelagic stages of cod were 0-10%, up to a maximum of 43%. These reductions resulted in a decrease in adult cod biomass of <3% for most scenarios, up to a maximum of 12%. In all simulations, the adult population remained at full reproductive potential with a sufficient number of juveniles surviving to replenish the population. The diverse age distribution helps protect the adult cod population from reductions in a single year's recruitment after a major oil spill. These results provide insights to assist in managing oil spill impacts on fisheries.