The North Atlantic Right Whale
A species on the edge of extinction struggles to recover
The right whale is one of nature’s oddest looking creatures; so much so that ancient mariners often mistook it for a sea monster.
“You’ve got this big narrow skull sticking in the air with all that baleen hanging down,” said Scott Kraus, Director of Research at New England Aquarium. “Then, way in the back, you have this arched tail pushing it along. It almost looks serpentine.”
But researchers who study right whales in the field get a more kind and gentle impression of the animal. Studying whales near Nova Scotia, WHOI biologist Mark Baumgartner once used an inflatable boat to approach a female whale. She suddenly and unaccountably stopped dead in the water, causing the boat’s momentum to carry it right into her wide body. Realizing that a freaked-out whale could easily flip his boat, Baumgartner yelled, “Hang on!”
But not to worry. “Damned if she didn’t just
roll over, take a look at us, then submerge with seemingly no motion
whatsoever, and disappear,” Baumgartner
This most endangered of great whales is distinguished by its large size (up to 59 feet long and 80 tons), dark color, “upside-down smile,” lack of a dorsal fin, and horny protuberances on the head called callosities.
callosities, often highlighted by intensely colored whale lice, were called “bonnets” by
sailors of old. “These guys had clearly been at sea too long,” Kraus
Callosities also turn out to be the “fingerprints” of right whales. Since 1980, Kraus and colleagues have been studying distinctive callosity patterns on some 250,000 “mug shots” to identify, catalog, and track the approximately 342 remaining North Atlantic right whales. About 150 contributors have donated their photos to this catalog, which includes nearly 32,000 whale sightings.
‘Urban whale syndrome’
Kraus also has a colorful phrase to describe the dovetailing histories of humans and right whales: “Our 1,000-year experiment in population biology.” Whalers started harpooning right whales a millennium ago in the Bay of Biscayne off Spain, and the assault was nonstop until commercial whaling was banned in 1935.
But starting from similar remnant populations of a few hundred, right whales in the North Atlantic and in the Southern Hemisphere have journeyed along very different paths in the last 70 years. Southern right whales, a distinct but related species, have recovered to a population of some 10,000 individuals, while their northern counterparts have been following the path of the dodo. Why? Since whaling ceased, southern right whales have lived free of most shipping lanes, pollutants, fishing areas, and other human activities.
By contrast, northern right whales tend to spend their lives within 50 miles of the highly urbanized North American seaboard, from calving areas along the southeastern U.S. coast to feeding grounds between Cape Cod and the Bay of Fundy.
Their proximity to the East Coast is the source of what Rosalind Rolland of the New England Aquarium has called “urban whale syndrome,” which threatens the North Atlantic breed. “Urban” whales contend with some of the heaviest shipping traffic in the world, a maze of fishing gear, agricultural and industrial runoff from everywhere east of the Rockies, contaminants from power plants and millions of cars, military testing, waste-dumping, and effluent containing pharmaceuticals and diseases.
“They’re swimming in an urban soup,” Kraus said. “We seem to be doing everything we possibly can to kill these whales.”
Half of known North Atlantic right whale deaths are caused by ship strikes and fishing-gear entanglements. Researchers are also finding diseases and toxins such as giardia, cryptosporidia, PCBs, organic chlorines, and mercury in whale tissues. Not coincidentally, the species’ reproduction rate is a third of what it should be.
The resulting body count is sobering indeed. Population projections calculated by WHOI biologist Hal Caswell and colleagues show that, at the current rate of decline, the right whale could become extinct within a century or two.
“How far can we push these animals?” Kraus asked. “In 100 years, a more enlightened society will ask, ‘What were these people thinking?’ ”
A multi-pronged research effort
This bleak outlook is why conservation and research on the right whale’s behalf has become more urgent. Regular aerial surveys study the distribution and movement of right whalesmaking photo IDs, counting newborns, and operating an early warning system to help vessels avoid the creatures. In addition, researchers are examining reproduction, acoustic monitoring, whale-safe fishing gear, toxins, and much more.
Baumgartner studies the right whale’s love affair with its favorite food, a rice-sized crustacean known as Calanus finmachicus, whose distribution is subject to ocean currents. Right whales must consume 2,625 pounds of Calanus every day to survive. They do so through 15-minute dives to the deepwater buffet, where clouds of Calanus are catered by swirling currents.
But Calanus itself has become a suspect in the survival saga of the right whale. These diminutive creatures at the bottom of the food chain may absorb and pass along contaminants and germs.
Beyond that, global warming and changes in ocean circulation may be affecting the distribution and availability of Calanus. If so, reproductively active females might not get enough nutrition to become pregnant, give birth, or lactate properly.
Such subtle and not-so-subtle factors cast long shadows on long-term right whale population projections. In the short term, we must find ways to stop killing them.
“If we managed to prevent just two mothers from dying each year,” Caswell said, “we could turn the northern right whale from a declining into a growing population.”