Biologische Probleme der Befischung mariner Ökosysteme.

New political, economical, and technical developments have changed the character of world fisheries. The exploitation of relatively small marine organisms, mainly pelagic fish, as a source of protein and the large distant-water fishing fleets of some countries operating worldwide make it possible to change marine ecosystems and particularly the upper parts of the food chain rapidly and drastically. The paper discusses recent changes in North Sea fish stocks and the ecological effects of antarctic whaling. [ABSTRACT FROM AUTHOR]