Whales are found throughout the world's oceans; however, many species are concentrated in cold northern
FIGURE 5.2 Baleen plates
Most whales have teeth. A handful of species filter their food through strong flexible plates called baleen. (See Figure 5.2.) Baleen is informally known as "whalebone." It is composed of a substance similar to human fingernails. Baleen whales strain large amounts of water to obtain their food, mostly zooplankton and tiny fish and crustaceans. Nearly all of the "great" whales are baleen whales.
Many marine mammals can vocalize (make sound). Whales, in particular, use sound to communicate with each other and for navigational purposes. Some whale vocalizations are audible to human ears. These sounds are known as "whalesong."
Whales are believed to be highly intelligent. Scientists use a measure called the Encephalization Quotient (EQ) to compare the relative intelligence of different species. EQ is a number based on the ratio of brain mass to body mass. For example, the average human brain is much larger than needed just to operate an organism the size of a human. This extra capacity indicates higher intelligence. Likewise, the brains of cetaceans, such as whales, are larger than expected, indicating that they probably are very intelligent animals.
Imperiled Whale Populations
As of February 2006 seven whale species had been listed for protection under the ESA in U.S. waters: humpback whales, sperm whales, bowhead whales, northern right whales, sei whales, fin whales, and blue whales. In addition, the ESA covers southern right whales in the southern hemisphere and gray whales, a species that inhabits the northwest Pacific Ocean. All of these whales are considered "great" whales. All but the sperm whale have baleen plates.
The National Marine Fisheries Service publishes annual Stock Assessment Reports (http://www.nmfs.noaa.gov/pr/sars/) that provide population estimates for endangered whale species in U.S. waters. Surveys of all species are not conducted every year. As of February 2006 final reports were available for the Pacific Coast (2004), Atlantic and Gulf Coasts (2003), and Alaskan Coast (2003). Summing survey results from each report provides a rough estimate of the minimum population of each species:
- Blue whale—1,692
- Bowhead whale—8,886
- Fin whale—5,004
- Humpback whale—5,655
- Northern right whale—291
- Sei whale—72 (based on incomplete data)
- Sperm whale—10,956
The NMFS notes that sei whale populations are extremely difficult to estimate. The whales prefer the open sea and rarely enter U.S. waters. Also, they tend to travel alone or in small groups, making them difficult to count.
The northern right whale is also known as the North Atlantic right whale because it is primarily found along the eastern coast of the United States. Although a few sightings have been confirmed in the North Pacific Ocean, there is no official estimate of that population. The National Marine Fisheries Service considers both populations to be of the same species. However, this opinion is disputed by some scientists. As of 2006 the World Wildlife Fund estimated that there were only 350 northern right whales in existence worldwide (http://www.worldwildlife.org/cetaceans/pubs/whales_current_status.pdf).
The northern right whale is the most endangered of the great whales. It was once the "right" whale to hunt because it swims slowly, prefers shallow coastal waters, and floats upon death. The species was nearly driven to extinction by whaling, which was banned in 1937 when the population had been reduced to an estimated 100. Despite decades of protection, the northern right whale population has not recovered, and as of 2006 the WWF estimated no population increase at all since the 1980s. Some scientists believe the animal is in grave danger of becoming extinct within only a few decades.
Threats to Whales
Whale populations are imperiled due to a long history of hunting by humans. As early as the eighth century, humans hunted whales for meat and whalebone (baleen). Whales were relatively easy for fishermen to catch because the animals spend a great deal of time at the surface of the water and provide a large target for harpoons. Advances in shipbuilding and the invention of the steam engine allowed fishermen greater access to whale populations, even those in Arctic areas that had previously been out of reach. By the nineteenth century, large numbers of whales were being killed for blubber and baleen. Blubber was rendered to extract whale oil, which was used to light lamps. Baleen was valued for making fans, corsets, and other consumer goods.
On December 2, 1946, the representatives of fourteen nations signed the International Convention for the Regulation of Whaling to form the International Whaling Commission (IWC). The signatory nations were Argentina, Australia, Brazil, Canada, Chile, Denmark, France, the Netherlands, New Zealand, Peru, South Africa, United Kingdom, United States, and the Union of Soviet Socialist Republics. The IWC was formed as a means to regulate the industry and limit the number and type of whales that could be killed. The Marine Mammal Protection Act of 1972 banned commercial whaling in U.S. waters. As of February 2006 there were sixty-six member nations in the IWC.
Centuries of whaling severely depleted whale populations. Low birth rates and high mortality rates due to a variety of factors have prevented many species from recovering. Like other marine animals, whales are endangered by water pollution and loss or degradation of habitat. However, the biggest threats to the northern right whale are believed to be entanglement in fishing gear and ship strikes.
ENTANGLEMENT IN FISHING GEAR
Entanglement of whales in fishing gear is a major problem, as noted by the National Marine Fisheries Service in "What Kinds of Fishing Gear Most Often Entangle Right Whales?" (Right Whale News, November 2005). The article describes recently published research related to whale entanglement. According to studies conducted in 2003 by the New England Aquarium, 71.9% of all known northern right whales have been entangled at least once in fishing gear. In 2005 researchers from Duke University investigated thirty-one cases of right whale entanglements and tried to identify the type of fishing gear involved in each case. They found that nearly a third of the whales had become entangled in lobster pot gear, mostly buoy lines. It was concluded that any type of fishing line that rises vertically in the water column poses a "significant entanglement risk" to northern right whales.
SHIP STRIKES
As shown in Figure 5.3 the National Marine Fisheries Service documented nearly 300 ship strikes on large whales off the U.S. East Coast between 1975 and 2002. Strikes on northern right whales are particularly troublesome because so few of the animals remain in existence. According to the NMFS fourteen northern right whales were confirmed killed by ship strikes between 1991 and 2002.
Figure 5.4 shows the locations of ship strikes on northern right whales that occurred between 1990 and 2000 along the North American coastline. Most strikes in U.S. waters occurred along the Massachusetts coast near Cape Cod and along the Georgia and northern Florida coastline. These areas are near or within critical habitats designated by the National Marine Fisheries Service for the whales. The southern critical habitat is the only known calving area of the northern right whale and is used from mid-November to mid-April. During calving season the NMFS performs aerial surveys and alerts ships about whales in their vicinity. In addition, federal law requires that ships remain 500 yards from right whales. Any sightings of dead, injured, or entangled whales must be reported to authorities.
In January 2006 the NMFS announced that a dead right whale calf had been reported by a fishing crew near the Florida shore. The animal was towed to shore and found to have large propeller marks and other wounds on its body, indicating it had been struck by a ship. The whale was male and only one month old.
In 2004 the National Marine Fisheries Service announced plans to propose rules requiring routing changes and speed limits for large vessels traveling in U.S. coastal waters frequented by northern right whales. The agency was still developing the rules in May 2005 when several environmental and animal groups petitioned the NMFS requesting that a temporary emergency regulation be imposed until the permanent rules could be issued. The petitioners asked for a speed limit of 12 knots (13.8 miles per hour) for all ships entering and leaving major East Coast ports during time periods of high use by right whales. In September 2005 the NMFS formally denied the petition. Two months later, three of the petitioners—the Defenders of Wildlife, the Humane Society of the United States, and the Ocean Conservancy—filed a lawsuit against the NMFS accusing the agency of "failing to protect" northern right whales as required by law. The lawsuit had not been resolved as of early 2006, when the petitioners filed papers that added the U.S. Coast Guard as defendants in the suit for their failure to adequately protect the whales in U.S. waters.
Whale Recovery Plans
Table 5.3 is a table published by the National Marine Fisheries Service in 2004 showing the status of recovery
FIGURE 5.3 Confirmed ship strikes on large whales, by species, 1975–2002
Table 5.3 also shows the recovery priority numbers assigned by the NMFS to each endangered whale species. Priority numbers can range from a value of 1 (highest priority) to 12 (lowest priority). The northern right whale has a priority level of 1, indicating strong concern about its abundance and chances for survival as a species.
The recovery plan for the North Atlantic right whale lists five goals for recovering the species. In order of importance, the goals are:
- Significantly reduce sources of human-caused death, injury and disturbance
- Develop recovery criteria based on demographic criteria
- Identify, characterize, protect, and monitor important habitats
TABLE 5.3 Endangered and threatened whale species in the United States, 2004
| TABLE 5.3 | |||||
|---|---|---|---|---|---|
| Endangered and threatened whale species in the United States, 2004 | |||||
| Species/ESU/DPSa | Date listed reclassified | Endangered Species Act status | Population/ESUa trend | Recovery priority numberb | Status of recovery plan |
| aESU=evolutionarily significant unit; DPS=distinct population segment. | |||||
| bRecovery priority numbers are designated according to guidelines published by the National Marine Fisheries Service (NMFS) on June 15, 1990 (55 FR 24296). Priorities are designated from 1 (high) to 12 (low) based on the following factors: degree of threat, recovery potential, and conflict with development projects or other economic activity. | |||||
| cDuring the timeframe for this report (2002–2004), two separate endangered species of right whale in the Northern Hemisphere were listed: the North Atlantic right whale (Eubalaena glacialis) and the North Pacific right whale (Eubalaena japonica). In January 2005, NMFS published a final rule to remove this distinction, thereby reverting to the previously used taxonomy of one endangered species—the northern right whale (Eubalaena glacialis)—for both North Pacific and North Atlantic populations. This report, therefore, uses the taxonomy at time of publication (northern right whale), noting that the taxonomic split may be reinstated in the future pending an upcoming status review and following ESA listing procedures. | |||||
| SOURCE: Adapted from "Table 1. ESA-Listed Species under NMFS' Jurisdiction Including Listing Status, Trends, Priority Numbers, and Recovery Plan Status," in Biennial Report to Congress on the Recovery Program for Threatened and Endangered Species (October 1, 2002–September 30, 2004), U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Office of Protected Resources, 2004, http://www.nmfs.noaa.gov/pr/readingrm/ESABiennial/bien04.pdf (accessed February 14, 2006) | |||||
| Whales | |||||
| Blue whale | 6/2/1970 | Endangered | Increasing | 7 | Completed 07/1998 |
| Bowhead whale | 6/2/1970 | Endangered | Increasing | 9 | None |
| Fin whale | 6/2/1970 | Endangered | Unknown | 7 | Draft completed 07/1998—under revision |
| Humpback whale | 6/2/1970 | Endangered | Increasing | 3 | Completed 11/1991 |
| Northern right whalec | 6/2/1970 | Endangered | Unknown | 1 | Completed 12/1991 (Atlantic), draft revision completed 2004; under development (Pacific) |
| Sei whale | 6/2/1970 | Endangered | Unknown | 3 | Draft completed 07/1998—under revision |
| Sperm whale | 6/2/1970 | Endangered | Unknown | 7 | None |
- Monitor the status and trends of abundance and distribution of the whale population
- Coordinate federal, state, local, international and private efforts to implement the recovery plan
User Comments Add a comment…