Local iwi has given permission for marine experts to examine three rare whales that stranded and died on a Northland beach.

The Gray's beaked whales were discovered on Ruakaka Beach, about two kilometres south of the Ruakaka Surf Lifesaving Club, by a member of the public at high tide about 7am yesterday.

Two whales lay dead 10 metres apart while the third was discovered about 100 metres north. All were male, measured between 4.5m and 5m long and each weighed at least one tonne.

Tutukaka-based marine mammal expert Ingrid Visser, Whale Rescue's technical adviser Steve Whitehouse, and Department of Conservation marine ranger Marie Jordan travelled to the beach at low-tide about 8.30am to determine the type of whale and to measure the dead mammals.


They stood guard while waiting for local iwi to arrive and bless the site before the whales were transported to a burial site nearby where a necropsy was expected to have been conducted late yesterday.

"These type of whales are very rare because they live deep in the ocean. We don't know why they swam here but they look fresh which suggests they died today," Dr Visser said yesterday.

She identified the whales through their long rostrum or beak and the overall body shape.

Dr Visser said the whales had no visible injuries or entanglement marks on them.

Mr Whitehouse said the whales became stranded, possibly about 4am, and said either drowning or choking on plastic could be the cause of death.

"I suspect they just drowned because they always fall over on their sides and when that happens, they can't lift their head sideways. We want to open up the stomach contents which would also enable us to check any parasitic wounds," he said.

It was not the first time Gray's beaked whales had been discovered on Northland beaches.

One such whale was found south of Hukatere on Ninety Mile Beach in February 2012. The cause of death was unknown.


Before that, two Gray's beaked whales stranded and died, one on Mimiwhangata beach and the other in a nearby bay, in October 2011.