| Summary: | No abstracts are to be cited without prior reference to the author. The traditional seal hunting on the Bothnian Bay spring ice (16th of April – 31st of May) resulted in a total of 136 grey seals shot in years 2003–2004. Hunters were obliged to deliver several samples from every individual killed: among other things the alimentary tract, uterus or baculum, and under jaw (for age determination from layers in cement of the canine teeth). Of the total catch, 71% were females, and of these 78% individuals aged more than 5 years old, which is the normal age in sexual maturity. This kind of sex and age ratio in the catch fits well with the population management regime that only aims to diminish the amount of seals. However, it its disadvantageous if the goal is to preserve the normal population structure among seals. Therefore, since the hunting quotas will most likely increase in the coming years, recommendations should be given to the hunters to favour the young grey seals as a catch. The analysis of the contents of the alimentary tract using fish otolithes and other hard particles showed that the herring (Clupea harengus) was clearly the most important prey item in the sea, where the floating ice greatly hindered fishing with gears. Herring was found in 103 grey seals (83.1%); the amount varied between 1-309 individuals per seal and was on average 41.1 ± 62.6. Four grey seals (3.2%) had eaten 1-2 salmon/trout (Salmo salar/trutta) and two grey seals (1.6%) 1-3 whitefish (Coregonus lavaretus). In addition nine other fish species were found in very limited numbers. The results suggest that hunting of grey seals on the spring ice in the Bothnian Bay may have some influence on the herring stock, but it does not, at least directly, help the management of the salmon stock. The paper discusses also the advantage of shooting young individuals and the size classes of fishes eaten by grey seals.
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