Includes the first review since 1980 of the world status of polar bears. Results of recent cooperative projects between Russian, American and Norwegian scientists are reported. Because the polar bear is at the top of the arctic marine food chain, it is an ideal species through which to monitor the cumulative effects of change - the presence of toxic chemicals, effects of nuclear wastes, global warming - in arctic marine ecosystems. An up-to-date review of present knowledge, management and research.