Thursday, November 26, 2009

Right whales return to local waters

A new listening device catches a whale call

By Mary Landers | http://savannahnow.com | 2009-11-26

"North Atlantic right whales have begun their annual return to Georgia waters.

At least one whale was recorded as it vocalized Tuesday off the coast of Savannah, just three days after the National Oceanic and Atmospheric Administration activated a listening buoy there.

"It hasn't been active long, and we have our first detection," said Barb Zoodsma, NOAA Fisheries' Southeast regional office right whale recovery program coordinator. Zoodsma hopes the acoustic data eventually will help researchers better delineate when and where right whales use Georgia waters.

The highly endangered large whales, whose total population is estimated at about 300-400, come to the waters off Georgia and Florida to give birth. It's their only known calving grounds.

Aerial surveys will begin Tuesday to look for right whales off Georgia. Surveys off South Carolina have been under way since mid-November.

Last year, surveys indicated 39 calves were born. Such record good news for the species was tempered by another statistic - five whales were discovered entangled in fishing gear.

Wildlife biologist Clay George of the Georgia Department of Natural Resources assisted in trying to free the animals. In all but one case, biologists succeeded in cutting loose heavy rope that wrapped around and dug into the animals' skin. And even in the case in which marine biologists couldn't catch up to the entangled whale because its tracking buoy malfunctioned, there appears to be a happy ending.

"The buoy and 50-foot of line came loose and was recovered by the Coast Guard offshore of New Jersey in March 2009," George said. "The whale was re-sighted in the Bay of Fundy by the New England Aquarium in August and appears to be gear-free, but not all areas of the body were seen, so we won't know for sure until it's re-sighted again."

Along with entanglements, ship strikes are the main threats to the species. One to two whales each year die from being hit by ships.

To address that problem, a federal regulation went into effect last year requiring commercial ships 65 feet or longer to reduce their speed to about 12 mph in areas where the whales feed and reproduce, as well as migratory routes in between. For the Savannah area, the speed restrictions are in force within 20 nautical miles of the coast from November through April. Recreational vessels are exempt from the rule, but are asked to comply voluntarily.

North Atlantic right whales are called urban whales because they live in close proximity to cities on the East Coast. They were hunted to near extinction because their slow swimming speed and tendency to float when dead made them the "right" whale to hunt.

Last year, about 200 individual whales were sighted in and around the calving grounds. Since only a minority of those animals - 78 of them - were moms and calves, scientists are left to speculate why the other whales make the long trip from their feeding grounds off New England and Canada. Right whales don't feed in southeastern waters, George said. And 20 years ago it was primarily mothers and calves seen here. Hypotheses for the arrival of non-breeding whales range from a social benefit to attraction to water of a certain temperature.

"It's a long way to go," George said. "It makes you wonder if they don't get something out of it."

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