Hectors 's Dolphin (Cephalorhynchus hectori) 



Hector's dolphins, which reach a maximum length of about 

 five feet, are one of the smallest cetaceans in the world. They 

 are known only from coastal waters of New Zealand and they are 

 most abundant along the east and west coasts of South Island. 

 Surveys carried out in the mid-1980s indicate a total population 

 size of perhaps 3,000 to 4,000 animals. Females appear to become 

 sexually mature at about seven to nine years of age and bear a 

 single calf every two years at most. Because of its low repro- 

 ductive potential, small population size, and preference for 

 coastal habitats, the species is particularly vulnerable to 

 potential adverse effects of human activities. 



In recent years, Hector's dolphins have been taken in signi- 

 ficant numbers incidentally in commercial and recreational gill- 

 nets. The problem has been particularly severe in the Banks 

 Peninsula area on the east coast of New Zealand's South Island. 

 Between 1984 and 1988, 223 dolphins were reported killed in that 

 area alone. The greatest number of dolphins have been entrapped 

 in gillnets during the austral summer (November through February) 

 when seasonal movements bring females inshore to bear their 

 calves and when gillnet fisheries are most intense. 



In response to this information, the New Zealand Department 

 of Conservation prepared a discussion paper in 1988 identifying 

 and assessing alternative ways to increase protection of Hector's 

 dolphins. In late 1988, the Department selected as its preferred 

 alternative, the establishment of a 1,140 square kilometer marine 

 mammal sanctuary in the waters around the Banks Peninsula. The 

 Sanctuary, named the Banks Peninsula Marine Mammal Sanctuary, and 

 its implementing regulations became effective on 1 November 1989. 



Within the Sanctuary, all forms of gillnetting are pro- 

 hibited during the summer months of November through February 

 when animals are most abundant. During the remainder of the 

 year, when dolphins are much less abundant in inner harbors and 

 bays, the regulations restrict gillnetting to recreational 

 fishermen and impose controls that reduce the likelihood of 

 animals drowning in nets. Specifically, the regulations apply 

 two levels of restrictions depending on location within the 

 Sanctuary. In the upper reaches of the Peninsula's four largest 

 harbors, gillnets may be no longer than 60 meters in length. 

 They can be left unattended between March and October. In all 

 other parts of the Sanctuary, nets can be no longer than 30 

 meters, may be set only in daylight hours, and must be attended 

 at all times. Throughout the Sanctuary, fishermen are prohibited 

 from carrying more than one gillnet in their boats. 



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