DOC attaches hook to rope on whale

The whale, with green rope around it. Photo / Department of Conservation

Department of Conservation staff have successfully attached a grapnel hook to rope entangled around the tail of a large humpback whale in the Far North.

The hook is connected to 50m of rope with large windy buoys attached. It is hoped the buoys will tire and slow the whale down enough to allow staff to get close enough to cut the debris from around the whale using a curved knife on a pole.

Two boats are involved in the operation in Doubtless Bay, one manned by DOC and the other by the Orca Research Trust's Ingrid Visser and her crew.

DOC spokesperson Carolyn Smith said it could take around two hours for the whale to tire enough for the crew to be able to approach and safely cut the debris free.

"We really need to make sure we tire the whale out before attempting to free it because it is so large. It's a bit like big game fishing on a much larger scale," Ms Smith.

"The whale in question is approximately 12 metres long and could weigh up to 30 tonnes, so it's essential DOC staff are trained and well-equipped to minimise any risks to their safety."

The technique used to remove the rope is called kegging, and has been adapted from an old whaling technique.

Mike Morrissey from the Kaikoura Area Office has had experience with this method in the past and said it is internationally recognised as the safest way of freeing an entangled whale.

The whale was spotted at 8.15am this morning. The operation was called off at 5.30pm yesterday due to limited remaining daylight and the grapnel hook breaking.

- With NZPA