October 16, 2009
The North Atlantic Right Whale: Doomed to Extinction?
Collisions with ships and entanglements will drive right whales toward extinction
Until the early 1990s, this critically endangered population showed small signs of recovery from the ravages of commercial whaling. However, by the 1990s research indicated that they had once again begun to decline, 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. Whereas right whales off South America reproduce every other year, the mean interval between births here is close to five years between the birth of calves.
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 to a record 39 in 2009, though many scientists worry that in most 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 and ship collisions
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 from lobster and crab traps. Any one of these entanglements may cause a right whale to drown if he is unable to reach the surface to breathe or the line may wrap so tightly that infection and a slow death eventually follow.
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 lead to crippling injuries or 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," is probably dead, because it 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. These sorts of sad stories play out year after year.
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.
In 2006, a female calf died in the waters off Florida, the only known right whale birthing ground, after becoming entangled in a gillnet. The National Marine Fisheries Service has stated that the loss of a single female poses significant jeopardy to the survival of the species, yet it is females who are dying in the largest numbers.
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, fast moving ships.
In a single 3-year period, 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.
Take reduction plan and other measures
The Marine Mammal Protection Act requires the publication and implementation of a Take Reduction Plan for all marine mammal populations suffering fishery-related mortality or serious injury rates exceeding the level that would allow the population to recover. Even though a series of deaths mandated additional risk reduction measures, the TRP affecting right whales was not revised until after The HSUS and other groups sued the NMFS and forced the requirement of new risk-reduction measures that took effect in 2009.
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.
Litigation by The HSUS has also resulted in mandatory speed limits for ships in certain high use areas to reduce the risk to right whales from collisions. NMFS has also been forced to shift shipping lanes to reduce risk in areas where the whales congregate seasonally.
Even though the Endangered Species Act and the Marine Mammal Protection Act require protections for right whales, the HSUS has been forced to file suit time and time again to win overdue protection for them. While NMFS continues to take its time to protect this critically endangered population, the clock is ticking for right whales.