Stefan Garthe¹ & Henri Weimerskirch²

Garthe, S. & Weimerskirch, H. 1999. Benefits and threats from fisheries to marine birds. In: Adams, N.J. & Slotow, R.H. (eds) Proc. 22 Int. Ornithol. Congr., Durban: 647. Johannesburg: BirdLife South Africa.

Recent studies have shown that fishing activities have very heavily influenced many ecosystems in the world. This also holds true for interactions between fisheries and seabirds. Although some seabird species are endangered by incurring mortality and changes in food availability caused by intense human fishing other species benefit considerably from fisheries by scavenging on fishery waste. The symposia aim to cover both positive and negative impacts of fisheries on seabirds. Mortality of seabirds induced by fishing vessels is most obvious in albatrosses which frequently become entangled in long-line fishing gear in the Southern Ocean, which has led to severe population declines in several species. Fisheries have also reduced the food available to marine birds in many regions of the world. In particular, fisheries for one or few target species in highly productive areas have caused low breeding success or even total failure in some seabird species. Discards (fish of undesirable species and lengths) and offal are discharged nearly everywhere fisheries occur. In some areas, discards comprise enormous quantities supporting millions of seabirds with surplus food. Their availability influences the distribution and feeding ecology of seabirds.