Only about 350 North Atlantic right whales still inhabit the waters off the East Coast of the United States and Canada, according to recent population assessments, and the news only gets worse. This tiny population faces extinction in less than two centuries unless the U.S. government seriously begins to address the causes of right whale mortality.
Until the early 1990s, this critically endangered population showed small signs of recovery from the ravages of commercial whaling. However, recent studies indicate that the survival rate of right whales has declined significantly, owing mostly to interactions with humans.
Doomed to Extinction
A 1999 report from the Proceedings of the National Academy of Science concluded that under current conditions, "the population is doomed to extinction," and that in less than 200 years, the last right whale will die with no descendants. The primary risks are entanglement in commercial fishing gear and collisions with ships. Reducing human-caused mortality is essential to the existence of the North Atlantic right whale.
The annual stock (population) assessment by the National Marine Fisheries Service identifies reduced reproduction as another major factor in the right whale's decline. The mean interval between births has increased from an average of one calf birth every 3.67 years in 1992 to a recent average of five years between calf births.
Birth rates for right whales fluctuate but remain low. Observers saw only one calf in the 2000 calving season. Since that time, the number born has increased, though many scientists worry that in some years the death rate still exceeds the birth rate. What makes this worse is that the death rate is highest for adult females, the segment of the population most vital to the future of the species.
Human-Caused Mortalities
A workshop conducted by the International Whaling Commission Scientific Committee agreed with U.S. scientists that entanglements and ship collisions were significant causes of right whale mortality, and it noted with "grave concern" the decline of this critically endangered population.
The IWC workshop also accorded the "highest priority" to measures that would immediately reduce mortality from entanglements and ship collisions. The workshop report, presenting the considered opinion of several of the foremost researchers on right whales, "strongly emphasizes there is no need to wait for further research before implementing any currently available actions that can reduce [human-caused] mortalities."
Entanglement
The entanglement of right whales in commercial fishing gear has been documented for more than three decades. Right whales may become entangled in nets, in the lines between nets or in buoy lines that go to the surface. Any one of these entanglements may cause a right whale to drown if he is unable to reach the surface to breathe.
Entanglement can also impair movement, making right whales more vulnerable to ship collisions or unable to eat properly, risking starvation. Fishing gear that is swallowed by or wrapped around a whale may also seriously injure the animal. ("Serious injury" is a legislative term that refers to injuries that may lead to death.)
Whales may even become entangled multiple times. One right whale was entangled in commercial fishing gear once in late 1997, and then two more times in 1998, before being freed of most of the gear. However, fishing gear remained in the whale's mouth. This whale, considered "seriously injured," has not been seen since 1998.
In 2001, the nation watched the tragic story of Churchill, a right whale who died slowly of infection despite several well-publicized attempts to disentangle him from the fishing line cutting into him. In 2002, at least seven right whales were observed entangled in fishing gear, one of whom died despite being disentangled. The others remain missing.
In March 2005, an adult female was found dead on a beach in Virginia. She had rope from commercial lobster fishing gear wrapped tightly around one of her flippers. As the rope cut into her bone, she apparently suffered a severe infection that resulted in her death. The loss of yet another reproductively mature female is a devastating blow to the population. NMFS has stated that the loss of a single female poses significant jeopardy to the species. In 2006, a female calf died in the waters off Florida, the only known right whale birthing ground, after becoming entangled in a gillnet.
Collisions with Ships
Collisions with ships have also occurred for many decades. In fact, as we look more closely at the causes of death in right whales, we're discovering that ship collisions play a greater role than previously thought.
Right whales are slow-moving animals who migrate through, and live in, coastal waters near busy ports. This has resulted in often-fatal collisions with large ships.
Between February 2004 and March 2007, 15 right whales were found dead. At least eight of them died as a result of collisions with ships; three were pregnant females with full-term calves. An additional right whale, struck by a sport fishing boat off Georgia in March 2005, was seriously injured and near death when last seen.
Take Reduction Plan and Other Measures
The Marine Mammal Protection Act requires the publication and implementation of a take reduction plan (TRP) for all marine mammal populations suffering human-caused mortality or serious injury rates exceeding the level that would allow the population to reach and maintain healthy numbers. The TRP affecting right whales was published in 2000, but NMFS itself has declared it obsolete, because whales were—and still are—being killed at a rate far higher than the small population can withstand.
The Endangered Species Act requires NMFS to reduce the human-related causes of right whale mortality. This includes not only fishery-related entanglement but also vessel collisions.
The death of a female right whale in 2003 required NMFS to amend the TRP, but the new version has yet to be released.
Recent successful litigation by The HSUS has forced NMFS to commit to releasing a new protection plan by Oct. 1, 2007. NMFS has also been forced to shift shipping lanes to reduce risk in areas where the whales congregate seasonally. Finally, it is preparing to issue requirements that large vessels slow down in areas where right whales are feeding or giving birth.
While NMFS continues to take its time to protect this critically endangered population, the clock is ticking for right whales.
Posted November 2005, updated July 10, 2007.
