Harbour porpoise (Phocoena phocoena) feeding ecology in the eastern North Sea

No abstracts are to be cited without prior reference to the author.

Results are presented on the analyses of harbour porpoise stomach contents from animals stranded and by-caught in Denmark and The Netherlands. A total of 58 non-empty stomach contents were collected and analysed from Denmark between 1985 and 1992, while 90 non-empty stomachs were analysed from The Netherlands between 1986 and 2003. In Denmark cod (Gadidae), viviparous blenny (Zoarcidae) and whiting (Gadidae) made up most of the diet while in the Netherlands whiting was the main prey, making up around ¾ of the total reconstructed prey weight. Variability in the diet was analysed in relation to year, season, cause of death, sex and size and results are compared with those from studies on this species from Scottish waters. Historically, herring was an important component of porpoise diet and we examine whether the recent increase in herring abundance in the North Sea has been reflected in porpoise diets. Preliminary estimates are also made on the amount of fish removed by harbour porpoises in the North Sea.