Spatio-temporal overlap of oil spills and early life stages of fish

Coupling an oil drift and fates model (Oscar) in an offline environment with an individual-based model (IBM) for Northeast Arctic cod (Gadus morhua) eggs and larvae enables us to quantify the exposure of eggs and larvae to oil from various oil spill scenarios. Oscar describes the spatio-temporal dispersal and fate of hydrocarbons, whereas the egg and larval IBM integrates the exposure of each individual. We can thus evaluate the effects of the time and location of an oil spill on the degree of exposure for individuals from different spawning grounds (SGs). In addition, we quantify how this effect is modified by the dynamic vertical positioning of eggs and the vertical behaviour of larvae. The principal findings of the study indicate that the mean egg and larval exposures for individuals from different SGs are highly dependent on the time and location of the spill and the vertical distribution of the offspring. Approximately 9.9, 4.7, 3.5, and 0.4% of the offspring would experience total polycyclic aromatic hydrocarbon (TPAH) concentrations above 1 A mu g l(-1) (parts per billion, ppb) for oil spill scenarios situated at Haltenbanken, Lofoten, and VesterAyenlen near the coast and near the shelf edge, respectively, based on the maximum TPAH concentrations in the water column along the individual offspring trajectories.