Record numbers of humpback whales have been spotted during the Conservation Department whale watch survey.

A record number of humpbacks have been spotted in Cook Strait during the current whale watch survey.

A group of former whale hunters in a lookout tower on Arapawa Island, and another group on a survey boat, counted 27 humpbacks near Jordy Rocks, Lucky Point and Wellington Bay on Saturday.

Survey co-ordinator Nadine Bott said the tally was the highest number of humpback whales counted in a day during the 12 years the survey had been operating.

The previous single day tally was 17, she said.

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Bott said 54 humpback whales had been spotted since the survey began on June 13.

Bott, a marine biologist, is leading the combined Department of Conservation and OMV New Zealand research team to assess the recovery of humpback whales since commercial whaling stopped in 1964.

"It's awesome," she said.

"We were buzzing. We got a report on Saturday morning at 8am that there were two humpbacks south of the Conway River, then we had another report of two more in the Tory Channel.

"It was all on from then and we didn't stop until well after 4pm. It was continuous, just unbelievable."

Most the whales were travelling in pairs, with some groups with three whales, Bott said.

Many were close to the shoreline about 3.5 km to 6 km off the coast.

One was spotted dragging a crayfish pot from a rope wrapped around its fluke, she said.

"We were unable to release the rope as we are not experienced enough to do that.

"The rope will slow the whale down but we only hope it doesn't cut into the tender flesh and become infected."

Biopsy samples and photographs were taken of the whales from the boat for genetic analysis and identification.

Bott said the photos of the flukes will be studied to see if any of the whales were regulars to the region.

The humpbacks are travelling through Cook Strait on the annual migration towards the Pacific.

Last year 92 humpback whales, one blue whale, several sperm whales and orca were spotted by the research team.

The survey ends on July 11.