Workshop on the Biology and Ecology of River Dolphins 

 (Species Survival Commission, International Union for the 

 Conservation of Nature and Natural Resources, Gland, 

 Switzerland) 



There are five species of fresh water river dolphins 

 which occur in several of the major river systems in China, 

 India, and South America. The biology, ecology, and status 

 of these species are not well known and all five may be 

 threatened or endangered due to hunting, incidental take, 

 habitat degradation, or other human activities. The purposes 

 of this Workshop, held in Wuhan, China, 2 6 October-6 November 

 1986, were to: review available information on the biology 

 and conservation of river dolphins; identify threats to the 

 dolphins and their habitat; and determine what can and should 

 be done to assure survival of the species. A preliminary 

 workshop report, provided to the Commission in November 1986, 

 confirms that all species of river dolphins are either 

 threatened or endangered. As described in Chapter IX, the 

 Commission subsequently recommended that the National Marine 

 Fisheries Service take certain steps to encourage and assist 

 needed protective measures. 



Relative Discreteness of Harbor Porpoise Populations in 



North-Central California 



(K. S. Norris, Ph.D., University of California, Santa Cruz) 



Substantial numbers of harbor porpoise are being caught 

 and killed in set net fisheries for halibut and other finfish 

 along the north central coast of California. The distri- 

 bution, size, and discreteness of populations being affected 

 by the fisheries are not known and therefore it is difficult 

 to judge the likely effects of the incidental take. Informa- 

 tion on harbor porpoise distribution and movement patterns 

 may best be obtained by radio-tagging and tracking a repre- 

 sentative sample of animals. The objectives of this pilot 

 project are to: (1) determine when, where, and how harbor 

 porpoise might most effectively be captured, observed, and 

 tracked or relocated in or near the areas affected by the 

 fisheries; and (2) develop safe and effective methods for 

 capturing, marking, radio-tagging, tracking, and relocating 

 harbor porpoise in and near the affected areas. The contract 

 report, due by 30 September 1987, will be reviewed by the 

 Commission, in consultation with its Committee of Scientific 

 Advisors, to determine whether the Commission should recom- 

 mend that the National Marine Fisheries Service initiate a 

 harbor porpoise radio-tagging/tracking program. 



10 



