William Trubridge, the world free-diving champion, can dive to the same depth as Maui’s and Hector’s dolphins
Maui’s dolphin is on the brink of extinction!
New Zealand dolphin (Hector’s and Maui’s dolphin) is Endangered. Maui’s dolphin (the North Island subspecies) is Critically Endangered. They are literally teetering on the edge of extinction, with a population of around 50 individuals remaining. Extending protection to all waters up to 100 m deep is most urgently needed for North Island waters.
Protected areas are shown in green. In the dark green areas, dolphins are protected from both gillnets and trawl nets. In the light green areas, gillnets are banned, but trawling continues to kill dolphins. The range of Maui’s and Hector’s dolphins is shown in red (New Zealand waters to 100m deep, except for northeastern part of North Island). As you can see, in most parts of their range the dolphins range much further offshore than the protected areas. As a result, they are still being caught in fishing gear (in particular gill nets and trawl nets). In most areas there is no indication that the number of dolphins caught each year has declined. Off the east coast of the South Island, the number of dolphins killed each year has roughly halved, to about 23 dolphins per year. However, a sustainable level of bycatch in this area is fewer than 4 per year.
Data on offshore distribution
A map of Banks Peninsula shows why. The map on the left, shows sightings from three summers (red dots) and three winters (blue dots) of surveys.
The protected area is indicated in grey. It is immediately obvious that the dolphins range well outside the protected area.
Effectiveness of current protection
Protection around Banks Peninsula was a major step in the right direction. Before the protected area was created, the Hector’s dolphin population in this area was declining at around 6% per year. Our latest research indicates that it is now declining at about 1% per year. That’s a major improvement and shows that reducing the use of gill nets and trawl nets in the area has been a huge help. But it still isn’t enough maintain the population long-term, let alone allow it to recover from the last 30 years of major decline.
What’s the problem?
The current protected area extends to 4 nautical miles offshore around Banks Peninsula. The problem is, the distribution of the dolphins extends to at least 20 nautical miles offshore. In fact, the dolphins’ distribution depends much more on water depth than distance from shore. If we extend dolphin protection to 100m water depth throughout their range that would make a huge difference. Essentially all of their foraging range would be protected.
Another problem with the Banks Peninsula Marine Mammal Sanctuary is that there is a loophole in each of the four large harbours. In Akaroa Harbour, Lyttelton Harbour, Pigeon Bay and Port Levy recreational fishers are allowed to use gillnets from 1 April to 1 November each year. The NZ Whale and Dolphin Trust has been warning the Ministry for Primary Industries that this risks killing New Zealand dolphins. During the Easter Break this year a dolphin was killed in a ‘recreational’ gillnet in Akaroa Harbour. We will encourage the New Zealand government to close this loophole and improve protection for these dolphins. After all, they are Endangered and only found in New Zealand.
What does this have to do with free-diving?
William Trubridge is putting his voice behind the campaign. See his website for more information about how he plans to let the world know about the plight of Hector’s dolphins. His recent free-diving record of 100m was called Project Hector.
Please write to the Minister for Primary Industries to ask him to protect Maui’s and Hector’s dolphins by extending protection from gillnets and trawl nets in all waters less than 100 m deep!
Mr Nathan Guy
Minister for Primary Industries