Media Release from WWF, the conservation organisation
Rare Maui's dolphin threatened by trawling
A recent survey of the critically endangered Maui's dolphin has shown that they are at risk from trawling. With a
population of around 100 remaining this is distressing news, says conservation organisation, WWF.
WWF commissioned research to confirm the distribution of the dolphins to find out how much overlap there is with fishing
activities. Maui's are only found off the west coast of the North Island and with such a low population, WWF believes
that all threats from fishing activity in the area must be eliminated.
"It takes just one human induced death every seven years for this fragile population to have little chance of recovery,"
says Chris Howe, WWF-New Zealand, Conservation Director.
Results of the aerial survey, funded by WWF and the Ministry of Fisheries, has shown that Maui's dolphins in winter are
found up to 4 nautical miles offshore. Trawling is allowed in this area and therefore the dolphins are unprotected
outside 1 nautical mile offshore and face risk of capture and drowning in trawl nets.
"The survey showed that Maui's dolphins overlap with trawl fisheries throughout their range. It has been reported that
the dolphins are occasionally caught and drown in trawl nets, so this is a real concern," says Dr Liz Slooten, Senior
Researcher, Otago University.
In winter dolphins appear to be evenly distributed between the shoreline and about 4 nautical miles offshore, whereas in
summer more of the sightings were much closer to shore. In both seasons they are still at risk because the surveys
sighted dolphins outside the areas closed to fishing.
"We are continually striving to find out as much as we can about these critically endangered dolphins. This research
showing their distribution indicates that fishing bans should be extended," says Chris Howe.
It is well known that set netting is a very serious threat to Maui's dolphins. The Ministry of Fisheries has created a
protected area for the dolphins, in which set netting is prohibited on the open coast near Dargaville to north of New
Plymouth out to 4 nautical miles. The evidence shows that dolphins are found out to 4 nautical miles, so the boundary of
the protected area may need to be extended further to be certain that the dolphins are protected.
"Dolphins take no notice of the boundary of the set net ban. It only takes one dolphin to stray outside the area for it
to be at risk, and with such a low population this is too great a risk," says Chris Howe.
"WWF calls on the government to look at an extension of the trawl net and set net bans to be certain the dolphins are
protected," says Chris Howe.
ENDS
* The first survey, carried out in January 2004, established that the population size is very small. There are
only just over 100 Maui's dolphins. The population estimate is 111 with a 95% confidence interval of 48-252.
* There is a concern that apart from a small part of the Manukau Harbour, the harbours of the North Island west
coast are not included in the protected area, and Maui's dolphins have been seen in several of these harbours. Otago
University researchers are planning a further research project to study the amount of time Maui's dolphins spend in
these harbours, using acoustic data loggers that record dolphins sounds.
* The research team are not entirely sure why the dolphins have such a strong preference for inshore waters during
summer, but food is the most likely reason. Several of the fish species eaten by the South Island Hector's dolphins come
closer to shore during summer to breed. So, most likely the dolphins are following their food inshore.
* Since late 2002, Maui's dolphin has been recognised as a distinct sub-species on the basis of a range of
characteristics including genetic make-up and morphology, and was formerly known as the North Island Hector's dolphin.
ENDS