Struggle to free whale snared by craypot

The humpback whale became caught up in craypot lines off the coast of Kaikoura. Picture / Ann McCaw

A distressed humpback whale entangled in craypot lines off the Kaikoura Coast has eluded attempts to cut it free.

Rope is wound around its middle with two buoys and the 35kg craypot attached.

"You feel just awful about it because you just really want to help them out there," said Department of Conservation staffer Paul McGahan. "They are such magnificent animals."

A member of the public alerted DoC to the whale's plight on Sunday as it was surfacing more than usual.

A specialist team based at Kaikoura tried for almost four hours to free it.

Workers in inflatables used a grapple hook and line to latch on to the craypot ropes and orange buoys to slow the whale down. They were planning to use long poles with specially designed tools to cut the lines but their attempts failed.

"The idea is to tire the whale, which gives us time to get close to it but it's quite a tricky operation," Mr McGahan said. "We managed to get a grapple on it but it dived and when it surfaced the grapple had come loose."

The team decided to try again the next day but could not find the whale.

The rescue attempt was carried out under procedures put in place after Tom Smith of Kaikoura was killed in 2003 when he swam to the aid of an entangled humpback and was hit by its giant tail.

DoC staff are prohibited from getting into the water during rescues.

DoC marine conservation officer Helen McConnell said anyone who saw the humpback should contact the department immediately. "We would try to get the team to it. Obviously it's not going to do too well out there."

Craypots line the coast near Kaikoura. DoC has been alerted to seven entanglements since 2001 but said at Mr Smith's inquest it was not feasible to limit the pots.

Meanwhile, the latest annual humpback survey showed the lowest number of sightings in three years.

DoC and retired whalers spent two weeks whale-spotting in Cook Strait near Tory Channel last month but this year saw only 14, compared with 35 the first year and 18 last year.

DoC scientist Dr Simon Childerhouse said the spotters had probably just been unlucky.

"It's probably just a year-to-year variation, but it is disappointing."

He estimated the population in the southern Pacific and off the east Australian coast was about 20 per cent of what it was in 1960, or around 300.

Japan's plan to kill 50 under its so-called "scientific whaling" programme could be catastrophic, he said.