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Scientists sedate giant whale at sea

Print | Comments () Posted by Beth Daley March 11, 2009 03:14 PM

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Update: I didn't meant to imply this was the first attempt at sedating a whale. The first was right whale Churchill (remember him) in the summer of 2001 off Cape Cod, as NOAA fisheries reminded me. This is the first time that a whale was sedated - and then disentangled.

By Beth Daley, Globe Staff

For the first time, a severely entangled North Atlantic right whale was given a shot of sedatives Friday in the open sea that allowed rescuers to remove thick fishing line cutting in to the whale’s upper jaw and left lip.

The entangled whale

The whale’s prognosis is uncertain but scientists say the exercise could prove invaluable in helping other whales that face severe injury or death when they become entangled in fishing rope.

Scientists have long been frustrated in trying to help entangled whales. The animals tend to avoid boats and if researchers do get close enough, they had to be careful the sometimes 40-ton leviathans don’t do anything unpredictable that would upset the boat and toss them into the sea.

Yet over the last decade, Woods Hole Oceanographic Institution, in collaboration with the National Marine Fisheries Service and two veterinary schools at the University of Florida and the University of Wisconsin have developed a sedation system to slow the animals and make them more approachable by rescue boats.

The injured animal was first sighted entangled east of Brunswick, Ga., on Jan. 14 by the Georgia Wildlife Trust aerial survey team.

An initial disentanglement failed on Jan. 22 when the whale evaded attempts to cut the line. The next day researchers tried again with the addition of a sedation dose, delivered by remote syringe and needle, but it still didn’t work.

Yet, the dose given appeared to make the animal feel less pain and rescuers tried – and failed – again on Feb. 1.

Then on March 5, rescuers ventured near the whale again, slowly increasing the dose they had used in January. Rescuers felt comfortable with the sedatives because they started with low doses that were known to be safe with dolphins, beluga and killer whales – and increased the dose very slowly. It still didn’t work that day but the sedative appeared to cause the whale to take shallower, more frequent breaths.

On Friday, they tried again with a little higher dose. Then, the whale tolerated repeated close encounters with a boat while researchers worked quickly to cut about 90 percent of the rope from the 40-foot, 40,000 pound animal.

The animal remains in very poor condition and has a guarded prognosis, but the disentanglement will give it a better chance for survival, officials say.

The North Atlantic right whale is the most endangered great whale, with a population of less than 400. Human activity—particularly ship collisions and entanglement in commercial fishing gear—is the most common cause of their deaths.

“This use of sedatives in a large free-ranging whale is novel and an exciting new tool in the large whale disentanglement toolbox,” said Michael Moore, a veterinarian and research biologist at WHOI who has led the investigation into safer whale disentanglements.

However, he said it does not address the underlying issue of how to let some fishermen "pursue a profitable business, without jeopardizing the survival of endangered species such as the North Atlantic right whale.”