New research shows Banks Peninsula Hector’s dolphins still at risk from set nets

18 May 2007 - Wellington

Contact: Liz Slooten,. Assoc Professor, Department of Zoology, OtagoUniversity, 03 479 7980, 027 447 4418; Kirstie Knowles, Forest & Bird Conservation Advocate, 04 801 2210, 021 426 984

Research using listening devices has found that Hector’s dolphins are going into the inner reaches of Akaroa Harbour in autumn – a time of year when set netting is allowed there.

Otago University Department of Zoology Associate Professor Liz Slooten says her research with fellow Associate Professor Steve Dawson shows that these endangered dolphins remain at risk of entanglement and drowning in set nets.

The study, using listening devices called porpoise detectors that pick up sounds made by dolphins in the water, shows that Hector’s dolphins continue to use the inner reaches of Akaroa Harbour at the time of year when set netting is allowed.

The marine mammal sanctuary around Banks Peninsula totally bans set netting for four months of the year from November to February, but allows recreational set netting for eight months from March to October in inshore parts of Akaroa and Lyttelton Harbours, Pigeon Bay and Port Levy.

Liz Slooten says the presence of the dolphins in these areas at times of the year when set netting is allowed means they are at risk.

“We have seen Hector’s dolphins within a few hundred metres of unattended set nets.  We now know that these dolphins spend quite a lot of time in these areas and not just in summer.  The current rules allowing set nets to be used are placing the dolphins in danger.”

Forest & Bird Conservation Advocate Kirstie Knowles agrees a total ban on the use of set nets within the sanctuary is necessary to adequately protect the dolphins.

“This research shows us that while set netting is allowed at certain times and places within the sanctuary, Hector’s dolphins are in danger.  Only a total ban on set net use inside the marine mammal sanctuary will provide the level of protection the dolphins need.”

“The marine mammal sanctuary has succeeded in reducing deaths of Hector’s dolphins, but the dolphins are still being killed in set nets, even inside the sanctuary boundaries.  We need to get serious about protecting these dolphins and ban set nets altogether.”

Hector’s dolphin facts:

• Hector’s dolphin (Cephalorhynchus hectori hectori) is the world’s smallest and rarest marine dolphin and is found only in New Zealand.  Hector’s dolphins can be distinguished from other dolphin species by their small size (less than 1.5 metres) and distinctive rounded dorsal fin.

• Hector’s dolphin is listed as endangered on the World Conservation Union (IUCN) Red List of Species Threatened with Extinction, with about 7000 remaining (down from about 26,000 in the 1970s when set netting began)

• Set nets are the most serious threat to Hector’s dolphins – Department of Conservation figures show set nets are responsible for more than 60% of deaths of Hector’s dolphins where the cause of death is known.  Set nets are banned or heavily restricted in many countries worldwide, including Australia, the UK and USA.  Set nets kill nearly everything that swims into them, including non-target marine life and seabirds, such as shearwaters, shags, penguins, seals and sea turtles as well as dolphins.

• Created in 1988, the Banks Peninsula Marine Mammal Sanctuary is one of just two marine mammal sanctuaries in New Zealand waters and was established to protect New Zealand’s second-largest population of Hector’s dolphin (the largest is off the South Island’s West Coast).  There are about 900 Hector’s dolphins around the peninsula and about 1200 in the wider Canterbury area.

• More than 25 Hector’s dolphins are caught each year in Canterbury alone.  Most are caught outside the marine mammal sanctuary, but at least eight have been caught inside the sanctuary boundaries between 1995 and 2005.

• Forest & Bird is calling for a nationwide ban on set netting to protect Hector’s dolphins and the critically endangered North Island sub-species Maui’s dolphin.  The Society is also seeking establishment of more marine mammal sanctuaries to protect key populations of these dolphins.