A double fluke as humpbacks spotted during this year's Cook Strait whale survey frolic in in the ocean.

It's been a bumper year for the Cook Strait whale survey with a record 137 humpback whales spotted and one sighting of a rare white humpback.

The Department of Conservation's annual Cook Strait whale survey has been running 11 years and ended this week - cut short three days by the past week stormy weather.

"Overall it's been an amazing survey year and we couldn't be happier," Marine mammal scientist and survey leader Nadine Bott said.

Each year, a team of former whalers, Conservation Department staff and volunteers converge on Arapawa Island, at the east head of Tory Channel in Marlborough. They are there to watch humpback whales migrating from their summer feeding grounds in Antarctica to their tropical breeding waters off New Caledonia.

Once whales are spotted, a boat is guided towards them to photograph the underside of their flukes or tails. These photographs are used for identification because each whale has unique white and black fluke markings. Skin biopsies are also taken to assess genetics, gender and age.

The survey collected 42 photo identifications and 72 biopsy samples, both of which are new records.

A tiny newborn humpback whale calf was also spotted - just the second time a calf had been seen in New Zealand waters following the only other sighting in July 2010.

A rare white whale, one of only four ever recorded in the wild, was spotted with distinctive features similar to a whale previously named Migaloo, Bott said.





