New Zealand's first marine mammal sanctuary was created around the Banks Peninsula in 1988,
to protect Hector's dolphins(Cephalorhynchus hectori). The sanctuary extends from Sumner Head
to Rakaia River and out to a distance of four nautical miles-an area of 1140 sq.km. The Hector
population is between 3-4000 making them one of the world's rarest marine dolphins, the Banks
Peninsula has about 500 of the mammals. With a maximum length of 145 cm, they are the smallest
marine dolphin in the world. They feed close to the shore, preferring shallow, often murky water, to
catch a range of species including yellow-eyed mullet and squid. This is also the ideal place to set
nets for fish. Like most marine mammals, they have a remarkably complex sonar/echo location
system. However, research indicates that they periodically switch off their sonar when in familiar
water. They are unable to identify monofilament nets, the type most favoured by today's net fishers.
Once entangled, the dolphins are unable to reverse out and drown. During the summer, the Hectors 
move close inshore to breed and raise their young. This coincides witht the peak of the setnet 
season. November to February appear to be the worst months for entanglement. The Hectors barely
produce enough offspring to replace the losses caused by natural mortality. Studies show their 
maximum life expectancy is 20 years. Females become sexually mature at 7-9 years, so a female
can only produce 4-7 calves in a lifetime. To conserve the Banks Peninsula population of Hector
dolphins, restrictions on the use of setnets have been introduced. There is a TOTAL ban on all 
setnetting in the shaded area shown on the map for four months from November 1st to the last
day of the following February. This setnet ban will also help reduce the entanglement of other
marine species such as hoiho/yellow-eyed penguin, korora/white flippered penguin and kekeno/
New Zealands fur seal. If you see entangled or stranded marine mammals, please contact your 
nearest DOC Office immediately. Line and hook fishing and all other forms of fishing are not affected.