Comprehensive protection required to save Hector's dolphin

April 8th, 2013 in Biology / Ecology
New Zealand dolphin distribution in red. Protected areas in green.


New Zealand dolphin distribution in red. Protected areas in green.

(Phys.org) —New Zealand's heavily endangered Hector's dolphin population could recover if protection measures were extended out to 100m deep throughout its habitat, according to a new University of Otago review.

Zoology Associate Professor Liz Slooten's review into the effectiveness of area-based management to reduce dolphin bycatch found that such an approach can succeed if certain key criteria are met.

These include the protected area being large enough, in the right location and key threats being effectively managed as well as removing impacts from fishing rather than displacing them and ensuring no new threats are added (such as marine mining, generation, or pollution).

The review is published in the international journal Endangered Species Research.

New Zealand and overseas experts have urged the government to 'turn the red sea green' and protect New Zealand dolphins out to the 100 metre depth contour, throughout their distribution.

Associate Professor Slooten says that a long-term study of the Banks Peninsula sanctuary shows that protected areas, where gillnets and trawling are banned, can work.

"At Banks Peninsula, have increased by 5.4% since the sanctuary's creation in 1988, and the previously rapid population decline has slowed substantially.

"However, nationwide, Hector's dolphins continue to slide towards extinction, mainly due to continuing bycatch in areas with few or no dolphin protection measures," she says.

Examples include the lack of any dolphin protection off the South Island north coasts, and that Hector's dolphins range to 6 nautical miles off the west coast of the South Island, but protection only extends to 2 nautical miles offshore, and then only for 3 months of the year, she says.

Several scientific organisations, including the of the International Whaling Commission and the International Union for (IUCN) have recently recommended that protection be extended out to 100 metres deep in Hector's dolphin habitats.

"Most Hector's do not range beyond waters of this depth. Extending protection out to this mark would largely eliminate the currently unsustainable level of bycatch."

Provided by University of Otago

"Comprehensive protection required to save Hector's dolphin." April 8th, 2013. http://phys.org/news/2013-04-comprehensive-required-hector-dolphin.html