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North Atlantic Right Whales

The western North Atlantic population of the northern right whale (Eubalaena glacialis) ranges, depending on the time of year, from the southeast coast of Canada through to Florida's east coast. It is a medium-sized baleen whale which, when full-grown, can reach a length of 55 feet and weigh up to 70 tons. Northern right whales can live up to 70 years though the average life span is not known. The species feeds on zooplankton, primarily copepods.

Northern right whales were originally found throughout the western and eastern North Pacific and on both sides of the North Atlantic but centuries of whaling have brought the species to the verge of extinction. In fact, it was so-named by whalers because it was considered the Ôright' whale to hunt: it swam slowly at the surface; was generally found close to shore; and contained large amounts of oil and blubber, making it commercially valuable and causing it to float when killed. It is considered the most threatened of the great whales and is one of the planet's most endangered species--with estimates suggesting that less than 600 to 700 individuals exist worldwide. The likely largest remaining population, numbering some 300 animals, resides off the U.S. and Canadian east coast. An unknown number, but probably in the low hundreds, live in the Okhotsk Sea (western North Pacific) while individuals or small groups continue to be sighted in the eastern Bering Sea. The northern right whale is considered to be virtually extinct in European waters; there have only been a few observations of single animals over the past decades.

A similar species, the southern right whale (Eubalaena australis), inhabits the ocean waters of the lower Southern Hemisphere.

The Problems

Whaling reduced the U.S./Canada east coast population of right whales so severely that, by 1900, per-haps a few dozen--or even less--remained. An international treaty in 1935 banned the hunting of all right whales which eliminated this threat to those remaining in the Atlantic Ocean (though right whales continued to be hunted in the Pacific and Southern Oceans, often illegally, until the late 1960s). With this protection, numbers along the U.S./Canada east coast began to gradually increase.
However, all evidence suggests that this population is now once again in decline. Indeed, a recently pub-lished study (1999) concluded that the U.S./Canada east coast population of northern right whales is "doomed to extinction" if current trends remain unchanged.
There appears to have been a recent drop in northern right whale fertility; females are now giving birth approximately every five to six years, much reduced from the three- to four-year calving interval exhibited during the 1980s. The average rate of reproduction for this population is now less than half of that of the southern right whale. Additionally, an increased incidence of skin lesions has been noted suggesting that the overall health of the population may be decreasing.

The Causes

At least 40% of all confirmed east coast right whale deaths over the last three decades can be attributed to two human-related factors:
- Ship strikes and collisions: The majority--approximately 90%--of human-related deaths are caused by ship strikes. Right whales appear to be particularly susceptible to this mortality factor given their preference for coastal environments, where shipping traffic is greatest, and because they typically spend much of their time at or just beneath the sea surface.
- Entanglement in commercial fishing gear (notably lobster trap lines and fixed gill nets): Though few northern right whale deaths due to fishery gear entanglement have been recorded, it is believed that this is an under-representation of the actual threat. Some 60% of photo-identified right whales exhibit scars assumed to be caused by fishing ropes and nets, and numbers of whales have been documented in potentially fatal entanglements or with entanglement injuries that were considered serious.
While much basic information is lacking, a variety of other factors may be playing a role. A reduction in genetic diversity (a result of reduced numbers of animals) may have lowered the population's overall fitness. Chemical pollutants, changes in food supply, or stresses associated with the increase in human activity and human-generated noise (e.g., boat traffic) may also be suppressing reproduction and/or reducing survival.

The Context

It is widely agreed that the most effective way to increase the survival chances of the east coast northern right whale is to reduce the number of deaths arising from ship strikes and fishery gear entanglement. In fact, it may now be essential if this population is to survive into the future. In this regard, a number of federal and state agencies and nongovernmental organizations have committed substantial expertise, funding, equipment and logistical support for a variety of monitoring and early warning system surveys and research and educational programs in efforts to better protect the species.
Whether these efforts to reduce ship strikes and fishery gear entanglements will be sufficient is unknown. Funding for critical programs is often lacking, and the development along coastal waters, with its associat-ed acoustic disturbance and habitat degradation, continues unabated. High volumes of shipping traffic and increasingly faster container vessels and ferries present a formidable management challenge.
The situation facing the northern right whale is not unique. The confluence of a variety of human-induced disturbances continue to push ever-increasing numbers of U.S. wildlife species--marine, terres-trial and freshwater--to the edge of extinction. Numerous others, though not endangered per se, exist as mere remnants of once profuse populations, and now play little or no role in environments in which they have existed for millenia.