The Collision Course of Whales and Humans
Ships and right whales are meeting too often at sea
If the sight of a swimming right whale is one of nature’s most majestic images, the sight of a dead one is among the saddest.
In 1999, a 60-ton, female right whale named Staccato was turned quite tragically from a heaving arc of sinew, energy, instinct, and grandeur into one of the world’s largest vehicular accident victims. She was found dead in the water off Wellfleet, Mass., the victim of a ship collision.
Staccato had been a prolific breeder, giving birth to six calves since 1977. Hence, her death by blunt trauma also put a huge dent in the growth potential of the dwindling North Atlantic population of right whales.
“We’ve known Staccato and her calves for a long time,” said Scott Kraus of the New England Aquarium (NEAq). “It’s like losing a friend and colleague.”
A recovery team from various institutions made certain Staccato’s death would not be in vain. There was much to be learned from what WHOI researcher Michael Moore called “the freshest right whale recovered in 10 years.” After the outsized carcass was towed to a nearby beach, scientists performed a three-day necropsy, which required such less-than-delicate surgical instruments as tractors and excavators.
The examination confirmed that Staccato died of wounds sustained during a collision with a ship: a fractured lower mandible, fractured vertebrae, and complications such as infection, blood clotting, and circulatory failure. Moore and other researchers added Staccato’s case study to the mounting body of evidence about what happens when right whales lose close encounters with ships.
Each year since 1991, one to three right whales have died or have been seriously injured by ships, according to the U.S. National Marine Fisheries Service (NMFS). This may represent only a fraction of whales killed by ships, as deaths may go unnoticed if the carcasses drift out to sea.
In February 2004, the carcass of one of the largest right whales in the Atlantic, a 53-foot female named Stumpy (for her damaged tail) was towed ashore in North Carolina. Like Staccato, Stumpy was a prodigious procreator who had given birth to at least five calves in her 40-year life. She was within a week or so of having her sixth when she was killed.
“When we lose Stumpy, we don’t lose just that whale,” said Charles “Stormy” Mayo of the Center for Coastal Studies. “We lose all of her reproductive future.”
On Nov. 24, 2004, yet another carcass of a pregnant right whale came ashore, this time in Ocean Sands, N.C. A preliminary examination indicated that the animal likely died from blood loss from a massive wound to the left tail fluke, probably caused by a ship propeller.
North-south migrating right whales are, quite literally, on a collision course with ships trekking east-west to major commercial and naval ports along the East Coast. Conservation efforts currently focus on two methods for curbing ship strikes: speed limits or rerouting the vessels.
When vessels cut their speed below 13 knots per hour in whale-populated waters, “ship strikes are reduced to almost none,” said Bruce Russell, a retired U.S. Coast Guard commander. Russell and Amy Knowlton of NEAq co-chaired an NMFS-sponsored committee to work with the shipping industry on recommendations to enforce mandatory speed limits and to reroute ships in critical habitats.
Moira Brown of NEAq, Knowlton, and collaborators from industry, science, and government in Canada recently persuaded officials to make a modest relocation of a major shipping lane that had gone directly through prime right whale habitat in the Bay of Fundya change that lessens the chance of ship strikes by 80 percent.
Efforts have also begun to educate international mariners to the risk of whale-ship collisions. Since 1998, large commercial ships traveling in U.S. waters have been required to report when they transit right whale habitats. Vessels also receive regular notices about the locations of right whales through an early warning system that dispatches information from aerial surveys.
Knowlton almost lost her life pioneering these surveys. In January 1987, she and four other whale surveyors had to ditch their failing twin-engine Cessna in 50-degree waters off the Georgia coast and wait for Coast Guard rescuers. Last winter, four employees of the Wildlife Trust weren’t so lucky. They all died in a crash while surveying right whales.
These efforts, however, are crucial for learning where right whales are. To this end, Christopher Clark of Cornell University is mobilizing a task force of “citizen scientists,” who will work like birdwatchers, spotting right whales along the East Coast and reporting to a central Web site.
Meanwhile, researchers want to learn more about the hydrodynamic forces exerted by ships traveling through water. Other scientists are doing pioneering forensic studies on whale bones to determine the threshold at which they break. Such information would provide a rational basis for ship speed limits that balance shipping interests with whale conservation.
Still other scientists are studying the physiology of whale hearing and whale behavior in response to shipsto understand why the whales do not evade collisions, and to test possible alarm systems that could warn whales to get out of the way. WHOI biologist Peter Tyack, for example, has found that right whales can definitely hear approaching ships and are sometimes observed avoiding them. But most disregard vessels, especially near busy shipping lanes.
“We tried looking at this issue from a whale’s point of view,” Tyack said. “There are a lot of vessels around. Whales are there to feed. If they stopped to avoid every vessel they heard, they would lose a lot of feeding time.”
Observations by WHOI biologist Mark Baumgartner indicate that mothers with calves spend a significantly longer time “walking” along the surface than other right whales and are at an even greater risk for ship strikes.
Scientists are the first to admit they need more studies and much more coordination. The urgency of this effort is symbolized by the team of determined researchers who gathered around Staccato’s corpse in 1999.