They are usually found in small groups of 2-8 individuals. Occasionally several groups come together to form a large temporary group of up to 50 dolphins, such as sometimes seen behind a fishing boat. Groups are relatively unstable with group members frequently changing from one small group to another.
What is being done to protect these rare dolphins?
The total number of Hector’s dolphins is thought to be about 7,000. They are classed as “endangered”. Despite best intentions its thought that the dolphin population may still be in decline due to fishing by-catch (in set nets), pollution and from being injured by boats. In 1988 a marine mammal sanctuary was put in place around Banks Peninsula. Commercial use of set nets is banned, and recreational fishers may use set nets only in certain times and places. These nets had been identified as a major killer of the dolphins, who were being caught in the nets and drowned. Ongoing research by the Marine Science Department of the University of Otago and Department of Conservation aims to find out just how successful the marine mammal sanctuary has been. Plastic litter is another threat to the well-being of the Hector’s dolphin. Because they are so playful, anything on the surface of the sea becomes a toy to play with. For example, a dolphin died simply because it swallowed a piece of plastic it was playing with. It died of starvation because the plastic blocked the dolphin’s digestive tract.
What can you do to help protect Hector's dolphins?
Purchase a ticket to cruise with us. For every customer who views or swims with the dolphins, we set aside a portion of the ticket price for research and study of the dolphins. We provide the Department of Conservation with daily data on the dolphins' movements and behaviour. Please tell as many of your friends and family as possible about this wonderful dolphin, this will help to raise awareness of the dolphins' situation.
Extending the Banks Peninsula marine mammal sanctuary
Hector's dolphins have been recorded drowned in both gill nets and trawl nets but the vast majority of the reports are from gill nets. Around Banks Peninsula gill nets were estimated to drown over 230 dolphins between 1984 and 1987 (Dawson and Slooten,1993) In response to dolphin deaths in the 1980s the Banks Peninsula Marine Mammal Sanctuary was established late in 1988. It covers an area of 1140 km2 around Banks Peninsula from Rakaia River to Sumner Head. The Sanctuary extends 4 nautical miles offshore and commercial gill-netting is banned all year round and recreational fishing is prohibited between 1 November and the end of February.
This restriction on gill netting has almost eliminated gill net deaths in the sanctuary but dolphins are still being killed north and south of the Sanctuary. Forest and Bird considers the sanctuary should be extended to include the area from Motunau to Timaru where a significant number of dolphins have been drowned in gill nets. The NZ government is also considering other options to extend the sanctuary throughout the year.