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New Jersey Endangered and Threatened Species Field Guide
North Atlantic right whale
Species Group: Mammal
The North Atlantic right whale is a large baleen whale. It may reach a length of up to 55 feet and weigh up to 70 tons. Females are larger than males. The right whale is large and rotund, with mottled brown to nearly black coloring. Both the chin and belly show some white. The highly arched jaw curves upward. The head and sometimes the lips are characterized by a series of bumps called callosities. The callosities are naturally gray but appear yellow or white because of massive infestation by whale-lice. The pattern of callosities can be used to identify individuals. The bonnet, the biggest of these bumps, is located just in front of two large blowholes. The right whale’s blow is V-shaped when seen from ahead or behind.
Instead of teeth, its mouth has great plates of horny baleen which extend from the upper jaw. These are used to strain food from large mouthfuls of water. The baleen plates are dark brownish to dark gray or black and up to 8 feet long.
The right whale has no dorsal ridge or fin. Their broad tail or flukes, which are dark underneath, have pointed tips that are very concave toward a deep notch.
Distribution and Habitat
As its name implies, North Atlantic right whales live within the North Atlantic Ocean. Other species of right whales inhabit different oceans: the North Pacific right whale (Eubalaena japonica) in the North Pacific Ocean and the southern right whale (Eubalaena australis) in the southern oceans. Right whales inhabit both the eastern and western portion of the North Atlantic Ocean, but there are very few remaining in the eastern portion. The western portion of the ocean, along the coast of North America, is home to the majority of the population. This is primarily a coastal species and is not typically encountered far offshore or in very deep water. They may also be found within large bays and estuaries.
Within the western North Atlantic Ocean, right whales feed during spring, summer, and fall in temperate and subpolar latitudes near eastern Canada and the northeastern U.S. During the winter, many individuals from this population can be found off the northeast coast of Florida and Georgia, their breeding and calving grounds. Some right whales, however, may remain at their northern feeding grounds during the winter.
Summer feeding habitat is within cold waters where prey is abundant. This is typically within relatively shallow waters. Winter breeding and calving habitat is within warm shallow waters. Prey is largely absent from these waters and right whales will typically go without any food during the months spent at the breeding grounds. Calving areas are near continental shores.
Right whales primarily feed on zooplankton, including small crustaceans called copepods and krill. They feed by filter feeding with their mouthful of baleen. They do so by taking a large mouthful of both prey and water, closing their mouth, and then pushing the water out of their mouth using their enormous tongue. The prey items are then left within the mouth, trapped by the strips of baleen, and ready to be swallowed.
Right whales use a feeding technique known as “skimming”. They feed by moving through patches of zooplankton in the water with their mouth open and catching the prey with their baleen.
During the summer, right whales will spend most of their time feeding and building-up fat in the cold waters of the North Atlantic. These fat stores will be necessary for the long migration to their winter breeding and calving grounds, located in warmer subtropical waters, where no feeding will take place for the entire winter. At their winter breeding and calving grounds, right whales may form small loose groups. These groups usually consist of a single adult female and several adult males.
Adult females give birth to their first calf at an average age of 9-10 years old while at the calving grounds during the winter, after a pregnancy which lasts for one year. Females will only become pregnant every three to five years. A mother and calf will form a very close attachment to each other and the calf will feed on the mother’s milk for up to one year after birth. Males play no role in raising their young.
Right whales may live for at least 50 years, but there is little data regarding longevity. Closely related species are thought to live for over 100 years. Their only known predator, besides humans, is the killer whale (Orchinus orca).
Current Threats, Status, and Conservation
All of the large whale species have been at risk of extinction due to a long history of whaling. The principal attraction of whaling was the whale's blubber, which yielded oil ideal for lamp oil and, much later, in the production of margarine. Baleen was also of value. Whalebones were also used in the manufacture of glue, gelatin and manure. Besides being eaten by humans, the meat has also been used in dog food and, when dried and crushed, cattle feed.
As early as the 1600s, the number of North Atlantic right whales may have already been substantially reduced during the previous century by Basques who hunted them in the waters between Labrador and Newfoundland. The right whale is so-named because it was considered the "right" whale for whaling ships: it swam slowly, was easy to approach and kill and it didn't sink after death. It was sought for both its oil and baleen, which was used for corset stays and other objects.
The North Atlantic right whale is among the most critically endangered large whales in the world. It is thought to have numbered at least 1,000 individuals during the early to mid-1600s. Its greatest declines were suffered during the 1700s. By the time international protection for right whales was initiated in 1935, they may have numbered fewer than 100. In 1998, the total population was estimated to be just 291 individuals. Between 1986 and 1992, there were suggestions that the stock was showing signs of slow recovery. However, a 1999 study concluded that between the early 1980s and late 1990s the northern right whale had suffered a decline in survival rates, a decline that was particularly marked in adult females.
In 1949, the International Whaling Commission prohibited commercial whaling of right whales due to the decline of the species. It was listed by the federal government as endangered in 1970 and, as a result of that federal status, was automatically added to the New Jersey endangered species list following enactment of the New Jersey Endangered and Nongame Species Conservation Act in 1973. Right whales are provided with additional protection with the Marine Mammal Protection Act of 1972.
Despite the ban on hunting, right whales face a number of threats, all of which are caused by humans. These threats include entanglement in fishing gear, collisions with ships, harassment by whale watchers, and habitat impacts including noise pollution.
One of the greatest threats to right whales is entanglement in fishing gear. Right whales often become wrapped-up in nets and/or fishing line around their tail, mouth, or other body part. Discarded nets and lines may float at sea for decades or become snagged on rocks or debris at the ocean bottom. Once entangled in fishing gear, the whale may face an agonizing death, pulling the gear along while it swims for many days, months, or even years, as the gear slowly cuts through their body and causes swimming to become more difficult. Scars on whale bodies are often an indication of a previous entanglement from which they escaped.
Collisions with ships are an increasing threat to right whales. The increasing number of large and fast ships, especially near busy ports such as the port of New York/New Jersey, results in whales and ships being in close proximity more often. Unfortunately, whales do not always know or have time to react to the approach of large ships and they get hit, usually resulting in their death. Right whales are especially slow-moving, compared to other large whales, and therefore more susceptible to being struck by ships.
Whale watching vessels may stress or accidently strike whales. There are whale watching guidelines in place which restrict ships’ approach distance and direction to whales and it is against the law to violate these. Federal law currently prohibits approaching any closer than 500 yards to a North Atlantic right whale unless permitted by the National Marine Fisheries Service.
Negative impacts to whale habitat may take the form of development, pollution, noise, overfishing, and climate change. Shipping channels, aquaculture, offshore energy development, and recreational use of marine areas may destroy whale habitat or displace whales which would normally use the area. Oil spills and other chemical pollutants are also a threat to whales and the prey which they feed on.
Another form of pollution is noise pollution. Whales’ primary means of communication, navigation, locating food, locating mates, and avoiding predators and other threats is through their sense of hearing, which is much more highly developed than that of humans. Noise pollution created by ship traffic or offshore construction may negatively impact whales by disrupting otherwise normal behaviors associated with migration, feeding, alluding predators, rest, breeding, etc. Any changes to these behaviors may decrease survival, simply by increasing efforts directed at avoidance of the noise and the perceived threat. Active sonar, such as that used by the Navy, also threatens marine mammals by disrupting navigation, foraging and communication abilities. There have been instances of whale stranding and death caused by acoustic trauma. This may be due to a fatal injury within the structure of the ear, or may result from the distressed animal surfacing too rapidly and developing nitrogen bubbles within their blood (decompression sickness). In addition to the direct threat posed by active sonar, it may indirectly harm marine species by causing changes in behavior.
Another potential cause for concern is the potential impact of global climate change. This issue may be the greatest long-term threat to the marine habitat and its species. Climate change may significantly alter the chemical balance of the seas, off-shore currents, and plankton distribution and abundance, thereby affecting migration routes of marine species and impacting the entire food web.
Right whales are the rarest of the large whale species and among the rarest of all marine mammals in the world. The North Atlantic right whale is critically endangered with only about 450 individuals remaining in the entire world. In fact, this may be the most globally rare animal species which occurs within the state of New Jersey. It is not currently known whether the species’ numbers are stable, declining, or increasing. Ship strikes and entanglements may be slowing their recovery. There is still no commercial hunt for right whales and there are not currently any proposals to begin hunting them, due to their incredibly low numbers. However, current models predict that the North Atlantic right whale may become extinct less than 200 years from now.
Although right whales are large animals, we don’t currently know a great deal about their habitat use off the coast of New Jersey. It has long been thought that right whales may only be using New Jersey waters as a migratory pathway between their summer feeding grounds in the north and their winter breeding grounds in the south. Possible feeding behavior has been documented in New Jersey waters and individuals have been observed very close to the shoreline. Surveys are currently being conducted off the New Jersey coastline in order to determine where whales are located, how many individuals are there, and during what time of year. Based on these findings, further knowledge regarding their habitat use in New Jersey waters may be gained and attention may then focus on protecting important habitats.
Text derived from the book, Endangered and Threatened Wildlife of New Jersey. 2003. Originally edited by Bruce E. Beans and Larry Niles. Edited and updated Michael J. Davenport in 2010.
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