January 30, 2011

Sedative Helps Rescue Whales From Fishing Lines

Researchers are now using sedatives to save endangered whales tangled in fishing line so they can pull them closer and cut the potentially fatal gear away.

The method was used January 15 off the Florida coast to free a young North Atlantic right whale from about 50 feet of line wrapped through its mouth and around its flippers.

"It's a big step for us," Michael Moore, a senior research specialist at the Woods Hole Oceanographic Institution in Massachusetts who was on the rescue team, told The Associated Press

The same team used the technique during another rescue of a free-swimming whale.

Wildlife authorities have tried different ways to save whales tangled in gear.

Fishing line is a major threat to the 300 to 400 critically endangered North Atlantic right whales that remain in the wild.  The whales generally migrate seasonally from the Lower Bay of Fundy in Canada during the summer to calving grounds off the Florida coast in the fall and winter.

Two North Atlantic right whales are known to have died from entanglement between 2005 and 2009, although 28 where found tangled during the same period.  Experts say those numbers include dead or tangled whales that have been spotted.

"It's a very slow, painful death," Michael Walsh, an associate director of the Aquatic Animal Health Program at the University of Florida who helped make the sedative mixture, told AP.

Rescue teams tie boats and buoys to lines trailing from the animal to slow it down and restrict a whales movement once one is found tangled.  

The success rates vary by species and tangle, but they are low for right whales, especially those with lines caught around their flippers and jaws.

"They're likely in a lot of discomfort," Jamison Smith, who oversees the freeing of large, told AP.  "They don't want to be ... harassed by a small boat."

NOAA officials thought of the idea of sedating whales in 1999 when they asked other scientists for help freeing a badly tangled right whale swimming off New England and in the Canadian Bay of Fundy.  

They devised a syringe mounted to a pole about 30 feet long.  They then dropped the pole from the front of the boat while the needle stroked the whale and injected antibiotics or sedatives.

Smith told AP that rescuers tried using the system in 2001 to sedate a tangled wale southeast of Nantucket, Massachusetts.  He said the system failed because movement from the boat would bend the needle, restricting the flow of sedatives.

New Zealand-based Paxarms built the team an air gun capable of hurling a 2-foot dart at a whale.  

The system comes with a distance finding and each dart is attached to a buoy to create a drag.  

The risk is that there could be too much medication, which could cause the whale to become disoriented and possibly drown.

Researchers first used the dart gun on a whale initially spotted off the Georgia coast in January 2009.  The first two attempts failed, but boat crews during the third attempt found that the whale was less hostile, allowing boats to get close and cut line.

Another successful attempt took place on Christmas Day 2010 when a 2-year-old right whale was spotted tangled off Florida's coast.


Image Caption: North Atlantic Right Whale mother and calf. (Credit: Wikimedia Commons/NOAA)


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