(Anchorage Daily News)
NOAA rescuers free whale calf from fishing line
By MIKE DUNHAM
mdunham@adn.com
Published: August 19th, 2011 05:59 PM
Last Modified: August 19th, 2011 06:02 PM
Federal officials spent the better part of Wednesday near Juneau trying to remove a buoy line from a five-month-old humpback whale.
Rescuing baby whales isn't specifically part of the National Oceanic and Atmospheric Administration's mission statement. But the staff from NOAA's Alaska Fisheries Science Center's Auke Bay lab are provided with training to do just that and they put the training to use several times each summer.
"Last year we received 14 reports of entangled humpback whales," said Kate Savage, a marine mammal specialist and veterinarian with the lab. "We responded to seven. Happily, this year has been less busy," a mere four reports.
Between 3,000 and 5,000 humpbacks feed in the waters of Southeast Alaska each summer, said Auke Bay research fisheries biologist John Moran, who took part in the rescue. "It's a stronghold for humpbacks," he said. "They're doing real well down here."
The call came in around 9 a.m. on Wednesday, Moran said. Boats taking tourists on whale viewing trips spotted the calf and its mother in Lynn Canal near the Shrine of St. Therese, a Catholic retreat north of Juneau. A buoy bobbed between the whales and it looked as if they might be ensnarled with the line. The lab's "large whale disentanglement team" -- both scientists and non-scientific staff -- was on the water by 10 a.m.
"The whale-watching community really helped us," said Moran. The tourist boats stayed with the whales, leaving their customary routes and taking turns keeping tabs, calling in help from other boats, until NOAA's research vessel, The Quest, could get to them.
ADVERTISEMENT
"That was important," said Moran. "If you lose sight of a whale, that's it. You can go up in a plane and you won't find it again."
The team in the 24-foot boat approached the 25-foot calf and its 45-foot mother cautiously. They inched close enough to toss a grappling hook around the half-inch line stretched between the whales and the buoy. The line probably came from a personal use crab or shrimp pot, Moran said.
A location transmitter was connected to the hook, permitting the team to back off for some distance and take time evaluating the extent of the problem and planning how to deal with it.
They took photographs and analyzed the lay of the ropes. They attempted to use an underwater camera but were thwarted by murky waters brought on in part by recent record rains.
Also, the whales were moving at such a clip -- Savage estimated 5 knots -- that the underwater boom was impossible to manipulate.
But what they saw gave hope. The line was only attached to the calf. The mother was staying close by, but was not wrapped in the same cord. And the cord was connected by a single wrap with a twist. It was free to slide back and forth and, the team determined, could be loosed with a single strategic snip.
However, the panicked calf kept swimming at full speed. And, according to a NOAA report, Mom "kept trying to position herself between the rescuers and the calf."
It was the unlucky calf's second run-in with human hazards during its short life. Moran previously photographed the same animal, noting scars on its back left by an encounter with a boat propeller.
But conditions for a whale rescue were generally ideal, said Moran, with good weather and a good chance to sever the line.
About 8 p.m., just west of the north end of Berners Bay, the team made its move. They got close enough to throw another grappling hook. This one had knife edges on the inside of its prongs. It landed where planned and, said Moran, "instantly cut through that line."
The buoy end popped loose. A short section of line was still trailing from the calf but the team expected it to drop off on its own.
The whales were about 25 miles from where they'd first been spotted, said Moran. "But of course, they weren't heading in a beeline. They were zigzagging."
The team watched the pair for another half hour before declaring mission accomplished and heading back to Auke Bay.
The calf, most likely born in Hawaii in March, could live into the 22nd century, Moran said. Recent research suggests that humpback whales can live 100 years.
0 comments:
Post a Comment