A "swat team" of whale rescue experts has undertaken an intensive three-day course in freeing whales that have become tangled in ropes and nets.

Entanglement is an increasingly common problem for marine mammals, with two cases in Far North waters in 2010. One of the mammals, a seven-metre humpback, was successfully freed after a two-day operation at Doubtless Bay.

Last month's course saw Department of Conservation staff and experts from Whale-Rescue.org combine a day of theory with two days of exercises on the water in the Bay of Islands.

Trainer Doug Coughran, a senior wildlife officer with Department of Environment and Conservation in Western Australia, was flown over especially to teach candidates from around the North Island.


Whale-Rescue.org spokeswoman Jo Berghan said the course was timely, given the increasing number of entanglements in New Zealand waters.

"Nobody wants to see a whale struggling and injured, but if and when it happens, we are ready to respond and assist the Department of Conservation in a rescue attempt," she said.

Recovering populations of humpback and southern right whales had led to more whales coming into contact with coastal fisheries during their annual migrations, sometimes resulting in entanglement in fishing gear and other marine debris. Whales could even bring nets or ropes from their winter breeding grounds or summer feeding grounds, she added.

Disentangling a whale in a marine environment was a high-risk activity, Mr Coughran said.

"Don't assume that the whale knows you are trying to help," he told the trainees. "It is potentially 45,000kg of distressed wild animal that may see you as a threat and respond accordingly."

For that reason alone, extensive safety training was vital, along with sound boat handling skills and whale behaviour knowledge and experience.

Members of the newly trained team were selected for their skills and knowledge, and were now part of a small international group specialising in whale disentanglement.

DOC ranger Laura Boren said anyone who saw an entangled whale should call the Department of Conservation on its 24-hour hotline (0800 DOC HOT) immediately. They should not enter the water with an entangled whale, or attempt to free it.