Help was fortunately close at hand for a humpback whale that found itself entangled in commercial fishing gear in the waters off Nanaimo yesterday.
Paul Cottrell, Department of Fisheries and Oceans Marine Mammal Response Program coordinator, said fisheries officers happened to be working just off Entrance Island on Thursday, June 10, following up on reports of suspected whale entanglements, when an emergency call came in from a commercial fishing vessel just five minutes away that had discovered an adult humpback whale entangled in its prawn trap line.
Cottrell was linked in to the call and advised crews at the scene to stay back and monitor the situation.
The animal, an adult estimated at about 12 metres long, had become so entangled it was anchored in place, possibly for as long as 24 hours, when it was discovered.
“It was a 50-string trap line with anchors on either end on 3,000 feet of rope, so there was a lot of gear that was holding this guy down, a lot of weight,” Cottrell said.
The marine mammal response boat and team rushed to the scene from the mainland and started assessing the situation with an aerial drone and remote-control submersibles. The commercial fisher provided information about the equipment that ensnared the whale.
“We don’t go in and cut things until we know exactly the gear configuration because you can make things worse if you cut the wrong line and also it can hurt the animal, so we took our time,” Cottrell said.
The whole operation took about six hours, including about four hours to disentangle the whale, which had the rope wrapped about four times around its tail.
“The rope that’s used is Polysteel. It’s nasty stuff and it’s fairly abrasive and the animal had injuries on the dorsal side, on the dorsal ridge, from I think when it became entangled … and it was just anchored in place,” Cottrell said. “Its tail stock was down and the animal was just breathing, maybe every five to 10 minutes, just holding position and trying to breathe. It was something.”
With the assessment done, Cottrell’s team was able to move in and cut the rope from around the whale’s tail as well as some loose lines and then they watched the animal for about 30 minutes.
“When it was freed … it took it a while to get back the tail fluke movement pattern, so it was slowly moving and we were just making sure all the gear was off,” Cottrell said. “There was one small piece of loose rope that’s left that we’re going to be monitoring, but there’s no tension on it and we believe it’s around the left pectoral fin. So, that’s something we’re going to watch over time, but it’s not considered life-threatening and it was loose, so we’re almost certain it will fall off on its own … By the end of about an hour after it was acting normally again and was moving on. It was fantastic.”
Cottrell said there are a large number of humpbacks in the area that have returned to the Salish Sea. The whales winter in Mexico and around Hawaii and return to the Salish Sea in the summer to feed on shrimp and other food sources. Last year about 30 whales returned, but a count for this year hasn’t been completed yet.
Humpback populations have been recovering after they were nearly hunted to extinction before whaling was halted in Canada in 1959.
The whale rescued Thursday has not been identified and its sex is unknown. That information will be gathered later with further observations.
“It couldn’t have worked out better,” Cottrell said. “I’m just still so happy.”