Entangled Whale Freed

A southern right whale / tohorā was freed from a blue cod pot line in a complex operation - the first time this species has been disentangled in New Zealand waters.

On Tuesday, the Department of Conservation, with the support of southern right whale experts, launched a rescue mission to free the whale, reported trapped near Rakiura on Saturday, after assembling a team of trained responders from across the country.

The 9-metre-long whale, thought to be a subadult male, was successfully freed off the coast of Bluff just after 4 pm on Tuesday, following a multi-day ordeal.

DOC Rakiura Operations Manager Jennifer Ross says successfully and safely freeing the whale, a taonga species for Ngāi Tahu, is an excellent outcome to a complex situation.

"Tohorā are among the most difficult whale species to disentangle. They are large, extremely strong and incredibly mobile – this makes any attempt to free them particularly dangerous. We are grateful to have been able to draw on the expertise of Simon Childerhouse from Blue Planet Marine, Environment Canterbury's Jemima Gardiner-Rodden – a Level 3 large whale disentangler, and DOC's specialist large whale disentanglement team based in Kaikōura led by Zac Penman, working together to safely get the best outcome."

The whale's ordeal began over the weekend. Fishers first reported the entanglement to DOC on Saturday morning. Because they were able to provide quick and accurate information, DOC staff were able to confirm the whale's location, and on Monday attached a satellite tracking buoy, funded by the Rock Lobster Industry Council, to keep track of its location while the safest course of action could be determined.

At the time, the whale appeared to not be in any immediate danger, however a welfare assessment by Massey University Professor Karen Stockin identified it was showing some signs of distress and there was risk of infection from the wound where the rope was tangled around its tail.

A southern right whale disentanglement has never been recorded in New Zealand before and requires an advanced level of expertise, Jennifer says.

"Tohorā can change direction quickly, roll 180 degrees, and swim backwards. They're more unpredictable than other whale species. A whale disentanglement is never straightforward, but this one was particularly complex."

Then, around 11 pm on Monday night, the satellite tracker showed the whale was on the move, heading north towards Bluff. It had broken free of the pot, but still had four buoys and around 100 m of rope coiled and draped from its tail.

"We had the data showing the tracker was on the move, but what we really needed was visual confirmation – there was a chance that the tracker itself had fallen off and was moving with the tides.

"Time was crucial – we needed to confirm the whale's location to take advantage of an open weather window."

On Tuesday morning, DOC's whale disentanglement team had arrived at the Bluff ferry terminal ready to cross Foveaux Strait to Rakiura, when they asked the crew on the RealNZ ferry if they could make a short detour to the tracker's last known location.

"The crew agreed, and because of that detour we were able to get eyes on the whale, and save crucial hours in the day."

With the right people supporting, and favourable sea conditions, the team were able to head out and successfully release the whale's tail just after 4 pm. The whale was last seen swimming normally into the sunset.

While this operation was successful, it was a timely reminder to fishers to only set as much line as they need for depth. The longer the lines, the more chance of entanglement, Jennifer says.

"At this time of year, many whale species are migrating, which increases the risk. They are also at risk of vessel strike; southern right whales don't have a dorsal fin, so they can be harder to spot in the water. This is a timely reminder to take care on the water and share our coasts. Slow down to 5 knots within 300 m of any marine mammals, keep 50 m away from whales and do not enter the water with them.

"We'd all been hoping for the best outcome for this whale and we thank everyone who has offered their support. Whale disentanglement is extremely dangerous and should never be attempted by anyone without the right training and gear, but people reporting sightings quickly has meant we're able to get the right people in place to try and free the whale.

"It's truly been a team effort. Thanks to everyone who has been involved."

Anyone out naturing on the water is reminded to keep their distance to all marine mammals and report sightings to 0800 DOC HOT (0800 362 468) or the SeaSpotter app.