Monitoring released pinnipeds and polar bears is critical for deter-mining the effectiveness of any clean up operation, as well as the overall impact of the oil on individual animals and the population as a whole. In some instances (e.g. nursing seals), visual recaptures may suffice. However, it is more likely that radio or satellite transmitters will be needed to follow widely ranging pinnipeds or polar bears. Such en-deavors are expensive but represent an investment as critical as the original clean up effort, and the costs must be incorporated into the restoration plan from the outset.
Whenever possible, recaptures of previously oiled and nonoiled animals should be included in any follow-up plan. These recaptures can be used to assess the condition of the fur or hair, measure body mass, and collect blood samples for clinical pathology and circulating hydrocarbon levels. Breeding colonies of pinnipeds should be moni-tored during subsequent pupping seasons to determine the long term effects of oil contamination on reproduction.