Because of its limited distribution, small numbers, and 

 vulnerability to gill net fisheries and other human activi- 

 ties, in January 1985, the National Marine Fisheries Service 

 designated the Gulf of California harbor porpoise as endangered 

 under the Endangered Species Act. As noted in previous Annual 

 Reports and in Chapter IX of this Report, the Commission has 

 provided funds to obtain carcasses of harbor porpoises taken 

 incidentally in the totoaba fishery, to train students in 

 methods of small cetacean identification, collection, and 

 museum preparation, and to determine the types and levels of 

 organic pollutants present in specimens. 



During 1988, the Commission will work with the National 

 Marine Fisheries Service, the Department of State, and other 

 agencies and organizations to identify measures that might be 

 undertaken to enhance the protection and recovery of this 

 species and its habitat and to encourage their implementation. 



Hector's Dolphin (Cephalorhynchus hector i) 



Hector's dolphin is one of four species of the genus 

 Cephalorhynchus and is among the smallest of the cetaceans. 

 Sexually mature adults are no more than 145 cm in length. 

 Hector's dolphins are found only in the coastal waters of New 

 Zealand and are most abundant along the east and west coasts 

 of the South Island. Surveys carried out during 1984-1985 

 indicate a total population on the order of 3,000 to 4,000 

 animals. 



All four Cephalorhynchus species are taken incidentally 

 in commercial and recreational gill net fisheries, and two 

 congeners, Commerson's dolphin (C. commersonii ) and the black 

 dolphin (C. eutropia) , are also taken directly for bait. 

 Although Hector's dolphin is not subject to a directed catch, 

 its seasonal movements into inshore waters to calve coincide 

 with periods of intense fishing. Thus, the incidental take 

 in one area may be as high as 10 to 15 percent of the local 

 population of that area. 



The species' preference for close inshore habitat also 

 makes Hector's dolphin vulnerable to pollutants such as heavy 

 metals and pesticide residues. Although the biological effects 

 of the pollutants are poorly known, contaminant levels in the 

 limited number of dolphins examined may suggest some cause 

 for concern. 



Long-term studies of the species indicate that females 

 become sexually mature at seven to nine years of age and pro- 

 duce, at most, one calf every two years. The actual recruitment 

 rate of the population is under study in the Banks Peninsula 

 area of the South Island. However, considering the extremely 



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