Scientists Mount Assault to Save Endangered Right Whales
Bijal P. Trivedi
National Geographic Today
|August 22, 2001|
A species is undoubtedly in trouble when each member is identified by a serial number and listed in a catalog along with an accompanying mug shot. The species in question is the North Atlantic right whale, which number only about 350.
Boat collisions and injuries from fishing lines have contributed greatly to the death of right whales. But scientists are optimistic that better knowledge of the creature's biology and behavior coupled with recent technological innovations could enable them to rescue the species.
In January, researchers plan to test a new type of buoy that will alert ships to the presence of whales nearby. Fishermen, meanwhile, are working to design fishing lines that hug the ocean floor, which would prevent entanglements with whales.
Marine biologists have obtained skin samples of right whales and are examining them to determine the health, gender ratio, and genetic makeup of the population.
Researchers led by Christopher Clark of the Bioacoustic Research Program at Cornell University have designed an underwater microphone to record whale "talk." The device, called a "pop-up buoy," is deployed by a ship and sinks to the ocean floor, hovering like a balloon tied to a brick. It contains a computer and hard disks that can store up to two months of recordings, and eventually pops up to the surface so scientists can collect the data.
"These buoys allow us to build a much richer picture of whale life and activity," said Clark.
Last year, Clark and his colleagues used "pop-up buoys" near Cape Cod, Massachusetts, to track the movements of whales. Sounds from each of the whales enabled the scientists to calculate its position. "Then we just connect all the dots to see where the whale is going," said Clark.
Big Picture, Detailed Samples
The recordings and the information about the whales' wanderings is giving scientists "an extraordinary picture of whale life," said Clark. "We see whales coming together in these big, very socially active groups, where they scream away for a few hours then go away and start up some place else," he said.
Early next year the researchers will hitch a version of their microphone-recorder device to buoys specially designed for the Gulf of Maine Ocean Observing System, which relays weather and ocean data to a Web site 24 hours a day. Clark hopes that by adding information about the whereabouts of the whales, cargo ships and fishing vessels can plan their routes to avoid hazards to the animals.
In another strand of the research, Moira Brown, a marine biologist at the Center for Coastal Studies in Provincetown, Massachusetts, is obtaining genetic information about the right whale population. From a boat, she uses a modified crossbow to collect skin samples when the whales surface. Scientists have skin samples from about 75 percent of the species.
The researchers also hover low above the whales in a Cessna Skymaster 337 to survey and photograph the population. Each whale has a unique set of white patches on its skincallosity patternswhich serve as natural identification tags for each animal.
"We also photograph the backs of these animals, which are decorated with scars, most often from collisions with ships and struggles with fishing lines," said Brown. "Almost two-thirds of the population have scarring," she noted, adding that almost the entire population of right whales has been photographed.
Together, the techniques have given scientists "the best profile of any endangered species yet," said Brown. "We have combined at least 20 years of right whale observations with genetic profiles of at least 75 percent of the species to create one of the most detailed profiles of an entire species."
"We know these guys inside and out," she said.
Drawing a Family Tree
In some cases, Brown said, "we know stuff that even the whales don't know."
When mating, right whales gather in groups of two to fortya single female surrounded by as many as several dozen males. "So it is not surprising that the female probably has no idea which male fathered her calf," said Brown. Using DNA obtained from the skin samples, Brown and her colleagues can determine who the father is.
From DNA samples of 200 of the whales, the researchers found that all of those sampled were descended from only five females. Because the population is small and lacks genetic diversity, scientists are concerned that the species may be more vulnerable to threatening diseases.
Brown expects that over the next few years, the researchers will obtain a complete genealogy of the whalesa family tree that shows how all the 350 right whales are related to each other.
Yet there is still much to learn.
The good news is that there is roughly an equal number of males and females. The bad news, however, is that females produce a calf only every three years, or even longer.
"In 2001 we had a bumper crop of calves. We saw 30 in all," said Brown.
"But this is not a recovery," she added, explaining that the whales' birth rate is unpredictable. In 2000, only one calf was born. "We need the 2001 birth rate to continue for about ten years to feel like the population has some sort of buffer zone," said Brown.
An international consortium of researchers is committed to developing whale-watching technology and modifying fishing equipment that will reduce the number of injuries and deaths. "We'll know if we're successful if we see a reduction in the number of scars," said Brown.
As Brown completed this interview, she received a call from researchers in Canada. They had just sighted a whale without scarring on its back.
To learn more about a fisherman's efforts to create whale-friendly fishing gear, watch National Geographic Today, only on the National Geographic Channel, 7 p.m. ET/PT in the United States. Click here to request it.
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