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Lifespan, longevity, and ageing

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Maximum longevity: 77 years (wild)
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Joao Pedro de Magalhaes
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de Magalhaes, J. P.
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Behavior

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Little is known about perception and communication in gray whales. Most whales communicate using a variety of high and low frequency "whale songs", including prolonged deep moans. Evidence suggests that gray whales use a simple array of short pulses and moans. Short pulses may be used for basic echolocation.

Communication Channels: acoustic

Other Communication Modes: choruses

Perception Channels: visual ; tactile ; acoustic ; echolocation ; chemical

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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John Berini, Special Projects
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Tanya Dewey, University of Michigan-Ann Arbor
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Conservation Status

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In 2003, the International Whaling Commission (IWC) established an indigenous hunting limit of 620 gray whales over five years, with no more than 140 individuals to be taken in a single year. In 2005, the IWC estimated that 400 individuals could be sustainably taken in any one year. Additionally, the major breeding lagoons of the eastern Pacific population are protected by their inclusion in the El Vizcaino Biosphere Reserve, limiting disturbances from boating, fishing, and coastal development.

The Committee on the Status of Endangered Wildlife in Canada designated the eastern north Pacific gray whale as a species of "Special Concern". After international protection from commercial whaling, gray whale populations experienced a 2.5% annual growth increase until 1998, when the population peaked at around 27,000 individuals. Over the following four years, however, the population declined by more than a third, possibly due to a lack of food in their summer feeding grounds. Since 2002, the eastern north Pacific gray whale population has steadily increased. The United States Fish and Wildlife Service lists the western north Pacific gray whale population as "endangered" and indicates that the eastern north Pacific stock was delisted in 1994. When the western and eastern Pacific populations are considered a single population, the IUCN considers them as a species of "Least Concern". However, the western Pacific population is separately listed as “critically endangered”.

US Federal List: endangered

CITES: appendix i

State of Michigan List: no special status

IUCN Red List of Threatened Species: critically endangered

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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Tanya Dewey, University of Michigan-Ann Arbor
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Benefits

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Gray whales have no known negative impact on humans; however, future conservation efforts may limit costal development.

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Benefits

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Gray whales have been hunted for thousands of years by indigenous populations along the coasts of North America and Russia. Commercial whaling for baleen, blubber, oil, and meat has occurred sporadically since 1900; however, over the past 400 years over-hunting has significantly decreased gray whale abundance. Although commercial whaling is illegal, indigenous subsistence hunting is allowed in North America and Russia. Finally, ecotourism and whale watching are important components of local economies along gray whale migratory routes.

Positive Impacts: food ; body parts are source of valuable material; ecotourism ; research and education

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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Tanya Dewey, University of Michigan-Ann Arbor
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Associations

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Gray whales are hosts to many endo- and ecto-parasites, including barnacles and whale lice. They are major predators of benthic amphipods (Amphipoda) and other marine invertebrates, including ghost shrimp (Palaemonetes). It is not known if gray whales contribute a significant degree of top down control on these prey species. Gray whales are primarily bottom feeders that disrupt muddy ocean bottoms, leaving feeding pits that are then colonized by other organisms. During feeding events, large mud plumes follow whales to the surface, carrying with them many invertebrates that are then eaten by sea birds and fish. Birds commonly associated with gray whales include northern fulmars (Fulmarus glacialis), red phalaropes (Phalaropus fulicarius), black-legged kitti-wakes (Rissa tridactyla), and thick-billed murres (Uria lomvia). Gray whales also eat herring eggs and spawn (Clupea pallasii pallasii) along their coastal migration routes and are considered to be opportunistic feeders that also feed upon schools of small baitfish.

Ecosystem Impact: creates habitat; soil aeration

Commensal/Parasitic Species:

  • barnacles, (Cryptolepas rhachianecti)
  • cyamids, (Cyamus)
  • trematode, (Ogmogaster antarcticus)
  • trematode, (Ogmogaster pentalineatus)
  • trematode, (Lecithodesmus goliath)
  • spiny-headed worms, (Acanthocephala)
  • nematodes, (Anisakis simplex)
  • northern fulmar, (Fulmarus glacialis)
  • red phalarope, (Phalaropus fulicarius)
  • black-legged kitti-wake, (Rissa tridactyla)
  • thick-billed murre, (Uria lomvia)
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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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John Berini, Special Projects
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Tanya Dewey, University of Michigan-Ann Arbor
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Trophic Strategy

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Gray whales are mysticetes (i.e., filter feeders) and are the only large cetacean known primarily as bottom feeders. They feed in shallow water with muddy or sandy bottoms or in kelp beds. To feed, they dive to the ocean floor and fill their mouths with a large volume of sediment. They force the sediment through their baleen plates, which trap a wide variety of crustaceans (Crustacea) including amphipods (Amphipoda) and ghost shrimp (Neotrypaea californiensis), as well as polychaete worms (Polychaeta), herring eggs (Clupea pallasii pallasii) and various forms of larvae. Food items are scraped off baleen plates with their large tongue and ingested.

Gray whales are considered opportunistic feeders and use group feeding strategies on schools of small fish during their southern migration. During feeding episodes, three to four whales corral a school of fish, as a single whale swims up through the school with its mouth agape. The head of the feeding whale emerges out of the water and remains in this position for up to a few minutes. Each whale in the group repeats this process until the school of fish has been significantly depleted.

Animal Foods: fish; eggs; mollusks; aquatic or marine worms; aquatic crustaceans; cnidarians; other marine invertebrates; zooplankton

Foraging Behavior: filter-feeding

Primary Diet: carnivore (Piscivore , Eats eggs, Eats non-insect arthropods, Molluscivore , Vermivore, Eats other marine invertebrates)

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Distribution

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Gray whales occur in the eastern and western north Pacific. Eastern north Pacific gray whales use shallow arctic feeding grounds during the summer, which are located in the Bering and Chukchi Seas. During the fall, they migrate south along the west coast of North America to their winter calving grounds, located in the warm waters off coast of Baja California. Four specific locations have been identified as important calving grounds for eastern gray whales: Laguna Ojo de Liebre, Guerrero Negro, Bahia Magdalena, and Laguna San Ignacio. Eastern gray whales are often seen during migration, off the western shores of the United States and British Colombia. During the return migration in the spring, a small population of about 80 individuals remains in more southerly Canadian waters. Relative to their eastern counterparts, western Pacific gray whales are poorly understood and are often referred to as the Korean, Western Pacific, or Okhotsk Sea stock. Their feeding grounds extend from the Okhotsk Sea, south along the east coast of Russia to the southern tip of south Korea. During the fall, they likely migrate to the South China Sea to give birth to young in sheltered lagoons and bays along the southern Chinese coast. However, this has not been well documented, as fewer studies have focused on this population.

A third north Atlantic gray whale population existed as recently as the 1700's and was described by whalers and colonists in North America, Iceland, Great Britain and Scandinavia. They have since been extirpated from the north Atlantic, likely due to over-hunting by whalers along with other anthropogenic influences (e.g., coastal development in their former calving grounds).

Biogeographic Regions: nearctic (Native ); palearctic (Native ); oriental ; arctic ocean (Native ); pacific ocean (Native )

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Habitat

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Gray whales feed in shallow coastal waters with muddy or sandy bottoms. They are migratory and rely on a variety of coastal habitats. During summer, they stay in waters of up to 60 m in depth and within 0.5 km to 166 km of shore. During fall, eastern gray whales migrate along the west coast of North America and spend winter in waters of less than 4 m in depth. These waters tend to be hyper-saline and are between 15 and 20 degrees C. Winter calving grounds usually have muddy or sandy bottoms and may contain eelgrass beds or be adjacent to mangrove swamps.

Range depth: < 4 to 60 m.

Habitat Regions: temperate ; tropical ; polar ; saltwater or marine

Aquatic Biomes: benthic ; coastal

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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John Berini, Special Projects
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Tanya Dewey, University of Michigan-Ann Arbor
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Life Expectancy

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Information on the lifespan of gray whales is limited, however, estimates range from 25 to 80 years old. Mortality rates are highest for young gray whales with an average annual calf mortality of 5.4%. About 75% of first-year mortalities occur during the first 2 weeks after birth. Mortality records indicate that calves represent about 91% of deaths at winter calving grounds, followed by yearlings (0 to 19.5%) and adults (0 to 5%). Annual adult mortality is estimated to be between 0.1 and 5% per year. Due to their large size and consequent feeding requirements, gray whales cannot be held in captivity.

Range lifespan
Status: wild:
25 to 80 years.

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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John Berini, Special Projects
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Tanya Dewey, University of Michigan-Ann Arbor
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Morphology

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Gray whales have mottled gray backs, a trait shared among several mysticete species. They are often hosts to dense infestations of skin parasites (e.g., barnacles and orange whale lice) that give their skin a rough and patchy appearance. In gray whales, these parasites often cover the entire body, however, in other baleen whales (right whales, Eubalaena australis and humpback whales, Megaptera novaeangliae), infestations are limited to specific areas of the body. Gray whale calves weigh between 500 kg and 600 kg at birth and are about 4.6 m in length. Adult females are slightly larger than males and are between 11.7 m and 15.2 m. Males are between 11.1 m and 14.3 m in length. Gray whales can weigh as much as 36,000 kg.

Unlike humpback whales (Megaptera novaeangliae), with which they are commonly confused, gray whales do not have dorsal fins. Rather, they have a large hump at the anterior end of the tail stock, followed by 7 to 15 knobs or knuckles of decreasing size. Gray whales have small, paddle-shaped flippers, compared to the large white flippers of humpback whales. The caudal fin has 2 wide, gray flukes separated by a deep notch. Their upper jaw extends past the lower jaw, and they have 2 to 5 throat pleats, which allow the mouth and throat to expand while feeding. Adults have 130 to 180 cream-colored baleen plates that are 5 to 25 cm in length.

Range mass: 36000 (high) kg.

Range length: 11.1 to 15.2 m.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: female larger

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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John Berini, Special Projects
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Tanya Dewey, University of Michigan-Ann Arbor
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Associations

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The only non-human predator of gray whales is the killer whale, also known as the orca (Orcinus orca). Nearly 18% of all gray whales show evidence of orca attack, with juveniles being the most vulnerable. Orca’s hunt in pods and can separate a calf from its mother. Once separated from its mother, the orca pod drowns the calf by holding on to its flippers and tail flukes with their teeth. Adult gray whales often place themselves between their calf and potential predators. When under attack, adults may also swim toward shallow water or kelp beds, where orcas typically do not enter.

Known Predators:

  • Killer Whales (Orcinus orca)
  • Humans (Homo sapiens)
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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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John Berini, Special Projects
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Tanya Dewey, University of Michigan-Ann Arbor
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Reproduction

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Although little is known of gray whale mating behavior, group mating events of three or more individual have been documented. Gray whales have a high reproductive rate, relative to other baleen whales.

Mating System: polygynandrous (promiscuous)

Gray whales mate throughout the year, however, most conceptions occur during the fall migration. After 13 to 14 months of gestation, females give birth to a single calf (one occurrence of twin fetuses was reported in 1987), which nurses until it is 6 to 7 months old. Eastern gray whale calves are born in late January in the warm coastal waters of Baja California, Mexico; however, early calving during the fall migration has been documented. Although less information is available for western gray whales, their winter calving grounds are thought to be along the coast of the South China Sea and likely have characteristics that are similar to the calving grounds of their eastern counterparts. Calving grounds are typically in shallow lagoons that are less than 4 m in depth and are hyper-saline. Preference for shallow water during calving may have contributed to the extirpation of the north Atlantic population in the mid 1700's.

Sexual maturation in gray whales occurs around 8 years of age, but has been documented in individuals as young as 5 and as old as 11. Nevertheless, studies suggest that size may be a better indicator of sexual maturity than age. Males average 11.1 m in length at time of sexual maturation and females average 11.7 meters. Sixty percent of the population consists of sexually mature adults. The average generation length (number of years between an individual's birth and the age at which they give birth) for gray whales is 22 years.

Breeding interval: Every other year

Breeding season: Year round mating with most conceptions occuring in late November to early December

Range number of offspring: 1 (high) .

Range gestation period: 13 to 14 months.

Range weaning age: 6 to 7 months.

Average time to independence: unknown years.

Range age at sexual or reproductive maturity (female): 5 to 11 years.

Range age at sexual or reproductive maturity (male): 5 to 11 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous

Gray whales replenish fat reserves during the summer. Pregnant females are especially dependent on these reserves. From the time they leave the summer feeding grounds in the fall, to when they return in early summer, females rely on fat reserves for energy and milk production. During times of limited food availability, interval between individual calving events may be extended.

Gray whale cows often hold newborn calves to the surface to help them breathe and are fiercely defensive of their young, especially against potential predators such as orcas (Orcinus orca) and human whalers. Gray whales inherit their mother's feeding grounds and are often seen, 1 year after they become independent, in their mother's feeding grounds.

Parental Investment: precocial ; female parental care ; pre-hatching/birth (Provisioning: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female); inherits maternal/paternal territory

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Kidd, T. 2011. "Eschrichtius robustus" (On-line), Animal Diversity Web. Accessed April 27, 2013 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Eschrichtius_robustus.html
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Travis Kidd, Northern Michigan University
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Alec Lindsay, Northern Michigan University
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John Berini, Special Projects
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Tanya Dewey, University of Michigan-Ann Arbor
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Biology

provided by Arctic Ocean Biodiversity 2011
Grey Whale: A long-range migrant of the North Pacific and Amerasian Arctic
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Sue Moore
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Lloyd Lowry
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Bodil Bluhm

Comprehensive Description

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Mottled gray; No dorsal fin, but a low hump followed by a series bumps (knuckles) on dorsal ridge of tail stock
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Sue Moore
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Bodil Bluhm

Trophic Strategy

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Only whale capable of benthic feeding; also feeds on epi-benthic and planktonic organisms; Wide range of prey including amphipods, cumaceans and other crustaceans, worms; little feeding occurs in the wintering grounds
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Bodil Bluhm

Life Cycle

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Size at birth 4.5m (15 feet) and 689kg (1500 pounds); Sexual maturity at 8 years; Females have calves every 2-3 years; Longevity over 40 years; Behavior; Short dives, usually flukes raised before prolonged dive; When feeding on benthic prey, often surfaces with mud streaming from mouth; Small groups, no lasting associations; Fiercely defend themselves and calf against predators/whalers
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Bodil Bluhm

Habitat

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Shelf & coastal, North Pacific to Chukchi & Beaufort Seas; Migratory: most animals winter in Baja California where calves are born
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Sue Moore
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Bodil Bluhm

Biology

provided by Arkive
The gray whale makes the longest migration of any mammal known, each autumn and spring they pass between their Arctic summer feeding grounds and the warm lagoons near the equator where females give birth (5). This yearly round-trip may entail individuals travelling up to 20,400 kilometres (2). Sexual activity can occur at any time of the year, but tends to be concentrated on the migration south (5). Little is known about the mating strategies of this species, but various numbers of individuals can be involved (5). The breeding cycle last two years: gestation takes about 13 months and the single calf is then suckled for a further seven months (5). At birth the calf is smooth compared to the encrusted adults and lacks sufficient blubber that would allow it to survive in Arctic waters (2). The mother may have to hold the calf near the surface to help it to breathe during the first few hours after birth (2). This species is the only cetacean to feed by straining the sediment on the sea floor (5). Individuals roll onto their sides after diving to the bottom and take large amounts of sediment into their mouth. As the whale rises to the surface it strains the contents of the mouth through the baleen, leaving a trail of mud and sand behind it. The invertebrate prey consisting of bottom-dwelling crustaceans, worms and molluscs is isolated in this way and swallowed (5). A number of seabirds are attracted to feeding gray whales, and take advantage of invertebrates that escape the filtering process (2). Sufficient fat reserves are stored in the feeding grounds to allow individuals to go without food during the breeding season; on return to the feeding grounds about a third of the body weight may have been lost (5). Killer whales are the only non-human predator of the gray whale. Attacks directed towards calves have been observed; adult gray whales often try to position themselves between the killer whales and the calf in order to protect it, and they may also head for shallow waters and kelp beds to take refuge from the attackers (2).
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Conservation

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In 1946, the International Whaling Commission (IWC) legally protected gray whales from commercial whaling, and the eastern Pacific stock has shown a remarkable recovery, increasing from the brink of extinction to around 21,000 individuals today (6). However, the western Pacific population that migrates along the east coast of Russia remains very small and Critically Endangered (1). Whale watching, particularly in southern California and Mexico, has developed into an extremely popular tourist attraction (4), allowing people to appreciate these awesome creatures in their natural environment and providing additional value to their conservation.
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Description

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A giant of the ocean, the gray whale is mottled dark to light grey in colour and is encrusted with patches of barnacles and whale lice (4). The species lacks a dorsal fin and instead has a series of bumps along a dorsal ridge on the final third of the back (2). There are two deep grooves on the throat, which allow the mouth to expand when feeding, and the baleen, which is used to filter food, is cream-white in colour. When surfacing, the 'blow' produced is distinctly bushy, short and forked, or 'heart-shaped', as it comes from two blowholes (2) (5). Females tend to be larger than males but otherwise the two sexes are similar in appearance (5). Whalers referred to gray whales as 'devilfish', due to the ferocity of mothers when separated from their calves (4) (5).
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Habitat

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This whale typically occurs in coastal waters no deeper than 100 metres (2). The eastern Pacific stock migrates annually from Arctic feeding grounds to breed in Mexican waters, whilst the western Pacific stock migrates along the east coast of Russia (6).
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Range

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There are two main stocks of the gray whale; one occurs along the east Pacific coast from Baja California to the Bering and Chukchi seas, the other occurs in the west Pacific from South Korea to the Okhotsk Sea (2). The gray whale once also occurred in the Atlantic Ocean, but became extinct here in the late 17th to early 18th century (5).
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Status

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Classified as Least Concern (LC) on the IUCN Red List (1), and listed on Appendix I of CITES (3). The northeast Pacific stock is classified as Least Concern (LC), and the northwest Pacific stock is classified as Critically Endangered (CR) (1).
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Threats

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The main threat to this whale has been hunting; humans have exploited the species for its oil, hide, baleen and meat (6). The activities of early whalers were, at the very least, a contributing factor to the extinction of the gray whale in the Atlantic Ocean (5), while massive over-exploitation in the 19th and 20th centuries almost destroyed the whole species (6). Whilst hunting is now banned a small quota is permitted to indigenous hunters (6). Shipping and industrial activities in the coastal migratory routes increase the risk of collisions with ships, entanglement in fishing nets and pollution. Furthermore, habitat degradation resulting from drilling and dredging is also a problem (1) (5).
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Diagnostic Description

provided by FAO species catalogs
Gray whales are easy to identify. They are intermediate in robustness between right whales and rorquals. The upper jaw is moderately arched, and the head is acutely triangular in top view and slopes sharply downward in side view. The flippers are broad and paddle-shaped, with pointed tips. The flukes have smooth S-shaped trailing edges, with a deep median notch. There is a dorsal hump about two thirds of the way back from the snout tip, followed by a series of 6 to 12 smaller "knuckles" on the dorsal ridge of the tail stock. There may be several (generally 2 to 5) short, but deep, creases on the throat that allow compression of the throat during feeding.

Although young calves are dark charcoal grey, all other gray whales are brownish grey to light grey. They are nearly covered with light blotches and white to orangish patches of whale lice and barnacles, especially on the head and tail. These patches of ectoparasites are very helpful in distinguishing this species.

The mouth contains 130 to 180 pairs of yellowish baleen plates, with very coarse bristles. The blow is bushy, heart-shaped when viewed from ahead or behind, and rises less than 3 to 4 m.

Can be confused with: Gray whales are unique in body shape and patterning, and there is usually little problem with identification. From a distance, however, they can sometimes be confused with right whale, bowhead whale, sperm whale or humpback whale.

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Marine mammals of the world. Jefferson, T.A., S. Leatherwood & M.A. Webber - 1993. FAO species identification guide. Rome, FAO. 320 p. 587 figs. . 
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Food and Agriculture Organization of the UN
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Size

provided by FAO species catalogs
At birth, gray whales are about 4.5 to 5 m long; adults are 11 to 15 m in length. Maximum body weight is over 35 t.
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Marine mammals of the world. Jefferson, T.A., S. Leatherwood & M.A. Webber - 1993. FAO species identification guide. Rome, FAO. 320 p. 587 figs. . 
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Brief Summary

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Most groups are small, often with no more than 3 individuals, but gray whales do sometimes migrate in pods of up to 16, and larger aggregations are common on the feeding and breeding grounds. Breaching, spy-hopping, and other aerial behaviours are common, especially during migration, and in and near the breeding lagoons of Baja California and mainland Mexico. The migration from winter breeding grounds in Mexico to summer feeding grounds in the Bering, Chukchi, and occasionally Beaufort, seas is witnessed by tens of thousands of people each year along the west coast of North America. Breeding occurs in winter, during migration, and in or near the Baja California breeding lagoons.

Gray whales feed primarily on swarming mysids and tube-dwelling amphipods in the northern parts of their range, but are also known to take red crabs, baitfish, and other food opportunistically.

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Marine mammals of the world. Jefferson, T.A., S. Leatherwood & M.A. Webber - 1993. FAO species identification guide. Rome, FAO. 320 p. 587 figs. . 
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Food and Agriculture Organization of the UN
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Benefits

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Conservation Status : The North Atlantic stock was apparently wiped-out by whalers in the 18th century. A western North Pacific (Korean) stock may also have been extirpated in the mid 20th century; its continued existence as a small remnant is still debated. The eastern North Pacific (California-Chukotka) stock nearly suffered the same fate twice, once in the late 1800s and again in the early 1900s. Both times, a respite in commercial whaling allowed the population to recover. About 170 to 200 from this latter stock are killed annually under special permit by commercial whalers on behalf of Soviet aborigines, and one or a few are taken in some years by Alaskan Eskimos. Since receiving IWC protection in 1946 and the end of research harvests in the late 1960s this population has increased, and now apparently equals or exceeds pre-exploitation numbers. IUCN:

Not listed.

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Marine mammals of the world. Jefferson, T.A., S. Leatherwood & M.A. Webber - 1993. FAO species identification guide. Rome, FAO. 320 p. 587 figs. . 
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Food and Agriculture Organization of the UN
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Gray whale

provided by wikipedia EN

The gray whale (Eschrichtius robustus),[1] also known as the grey whale,[5] gray back whale, Pacific gray whale, Korean gray whale, or California gray whale,[6] is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of 14.9 meters (49 ft), a weight of up to 41 tonnes (90,000 lb) and lives between 55 and 70 years, although one female was estimated to be 75–80 years of age.[7][8] The common name of the whale comes from the gray patches and white mottling on its dark skin.[9] Gray whales were once called devil fish because of their fighting behavior when hunted.[10] The gray whale is the sole living species in the genus Eschrichtius. It was formerly thought to be the sole living genus in the family Eschrichtiidae, but more recent evidence classifies members of that family in the family Balaenopteridae. This mammal is descended from filter-feeding whales that appeared during the Neogene.

The gray whale is distributed in an eastern North Pacific (North American), and an endangered western North Pacific (Asian), population. North Atlantic populations were extirpated (perhaps by whaling) on the European coast before AD 500, and on the American coast around the late 17th to early 18th centuries.[11] However, in the 2010s there have been a number of sightings of gray whales in the Mediterranean Sea and even off Southern hemisphere Atlantic coasts.

Taxonomy

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Skeleton

The gray whale is traditionally placed as the only living species in its genus and family, Eschrichtius and Eschrichtiidae,[12] but an extinct species was discovered and placed in the genus in 2017, the Akishima whale (E. akishimaensis).[13] Some recent studies place gray whales as being outside the rorqual clade, but as the closest relatives to the rorquals.[14] But other recent DNA analyses have suggested that certain rorquals of the family Balaenopteridae, such as the humpback whale, Megaptera novaeangliae, and fin whale, Balaenoptera physalus, are more closely related to the gray whale than they are to some other rorquals, such as the minke whales.[15][16][17][18] The American Society of Mammalogists has followed this classification.[19]

John Edward Gray placed it in its own genus in 1865, naming it in honour of physician and zoologist Daniel Frederik Eschricht.[20] The common name of the whale comes from its coloration. The subfossil remains of now extinct gray whales from the Atlantic coasts of England and Sweden were used by Gray to make the first scientific description of a species then surviving only in Pacific waters.[21] The living Pacific species was described by Cope as Rhachianectes glaucus in 1869.[22] Skeletal comparisons showed the Pacific species to be identical to the Atlantic remains in the 1930s, and Gray's naming has been generally accepted since.[23][24] Although identity between the Atlantic and Pacific populations cannot be proven by anatomical data, its skeleton is distinctive and easy to distinguish from that of all other living whales.[25]

Many other names have been ascribed to the gray whale, including desert whale,[26] devilfish, gray back, mussel digger and rip sack.[27] The name Eschrichtius gibbosus is sometimes seen; this is dependent on the acceptance of a 1777 description by Erxleben.[28]

Taxonomic history

A number of 18th century authors[29] described the gray whale as Balaena gibbosa, the "whale with six bosses", apparently based on a brief note by Dudley 1725:[30]

The Scrag Whale is near a kin to the Fin-back, but instead of a Fin upon his Back, the Ridge of the Afterpart of his Back is cragged with half a Dozen Knobs or Nuckles; he is nearest the right Whale in Figure and for Quantity of Oil; his Bone is white, but won't split.[31]

The gray whale was first described as a distinct species by Lilljeborg 1861 based on a subfossil found in the brackish Baltic Sea, apparently a specimen from the now extinct north Atlantic population. Lilljeborg, however, identified it as "Balaenoptera robusta", a species of rorqual.[32] Gray 1864 realized that the rib and scapula of the specimen was different from those of any known rorquals, and therefore erected a new genus for it, Eschrichtius.[33] Van Beneden & Gervais 1868 were convinced that the bones described by Lilljeborg could not belong to a living species but that they were similar to fossils that Van Beneden had described from the harbour of Antwerp (most of his named species are now considered nomina dubia) and therefore named the gray whale Plesiocetus robustus, reducing Lilljeborg's and Gray's names to synonyms.[34]

Scammon 1869 harvnb error: no target: CITEREFScammon1869 (help) produced one of the earliest descriptions of living Pacific gray whales, and notwithstanding that he was among the whalers who nearly drove them to extinction in the lagoons of the Baja California Peninsula, they were and still are associated with him and his description of the species.[35] At this time, however, the extinct Atlantic population was considered a separate species (Eschrischtius robustus) from the living Pacific population (Rhachianectes glaucus).[36]

Things got increasingly confused as 19th century scientists introduced new species at an alarming rate (e.g. Eschrichtius pusillus, E. expansus, E. priscus, E. mysticetoides), often based on fragmentary specimens, and taxonomists started to use several generic and specific names interchangeably and not always correctly (e.g. Agalephus gobbosus, Balaenoptera robustus, Agalephus gibbosus). Things got even worse in the 1930s when it was finally realised that the extinct Atlantic population was the same species as the extant Pacific population, and the new combination Eschrichtius gibbosus was proposed.[30]

Description

Grauwal.png

The gray whale has a dark slate-gray color and is covered by characteristic gray-white patterns, scars left by parasites which drop off in its cold feeding grounds. Individual whales are typically identified using photographs of their dorsal surface and matching the scars and patches associated with parasites that have fallen off the whale or are still attached. They have two blowholes on top of their head, which can create a distinctive heart-shaped blow[37] at the surface in calm wind conditions.

Gray whales measure from 4.9 m (16 ft) in length for newborns to 13–15 m (43–49 ft) for adults (females tend to be slightly larger than adult males). Newborns are a darker gray to black in color. A mature gray whale can reach 40 t (44 short tons), with a typical range of 15–33 t (17–36 short tons), making them the ninth largest sized species of cetacean.[38]

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A close-up of a gray whale's double blow hole and some of its encrusted barnacles

Notable features that distinguish the gray whale from other mysticetes include its baleen that is variously described as cream, off-white, or blond in color and is unusually short. Small depressions on the upper jaw each contain a lone stiff hair, but are only visible on close inspection. Its head's ventral surface lacks the numerous prominent furrows of the related rorquals, instead bearing two to five shallow furrows on the throat's underside. The gray whale also lacks a dorsal fin, instead bearing 6 to 12 dorsal crenulations ("knuckles"), which are raised bumps on the midline of its rear quarter, leading to the flukes. This is known as the dorsal ridge. The tail itself is 3–3.5 m (10–11 ft) across and deeply notched at the center while its edges taper to a point.

Pacific groups

The two populations of Pacific gray whales (east and west) are morphologically and phylogenically different. Other than DNA structures, differences in proportions of several body parts and body colors including skeletal features, and length ratios of flippers and baleen plates have been confirmed between Eastern and Western populations, and some claims that the original eastern and western groups could have been much more distinct than previously thought, enough to be counted as subspecies.[39][40] Since the original Asian and Atlantic populations have become extinct, it is difficult to determine the unique features among whales in these stocks. However, there have been observations of some whales showing distinctive, blackish body colors in recent years.[41] This corresponds with the DNA analysis of last recorded stranding in China.[42] Differences were also observed between Korean and Chinese specimens.[40]

Populations

North Pacific

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Gray whale breaching
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Gray whale spouting along shores of Yachats

Two Pacific Ocean populations are known to exist: one population that is very low, whose migratory route is presumed to be between the Sea of Okhotsk and southern Korea, and a larger one with a population of about 27,000 individuals in the eastern Pacific traveling between the waters off northernmost Alaska and Baja California Sur.[43] Mothers make this journey accompanied by their calves, usually hugging the shore in shallow kelp beds, and fight viciously to protect their young if they are attacked, earning gray whales the moniker, devil fish.[44]

The western population has had a very slow growth rate despite heavy conservation action over the years, likely due to their very slow reproduction rate.[45] The state of the population hit an all-time low in 2010, when no new reproductive females were recorded, resulting in a minimum of 26 reproductive females being observed since 1995.[46] Even a very small number of additional annual female deaths will cause the subpopulation to decline.[47] However, as of 2018, evidence has indicated that the western population is markedly increasing in number, especially off Sakhalin Island. Following this, the IUCN downlisted the population's conservation status from critically endangered to endangered.[48][45]

North Atlantic

The gray whale became extinct in the North Atlantic in the 18th century.[49] Other than speculations, large portions of historical characteristic of migration and distribution are unclear such as locations of calving grounds and existences of resident groups.

They had been seasonal migrants to coastal waters of both sides of Atlantic, including the Baltic Sea,[50][51] Wadden Sea, the Gulf of St. Lawrence, the Bay of Fundy, Hudson Bay (possibly),[52] and Pamlico Sound.[53] Radiocarbon dating of subfossil or fossil European (Belgium, the Netherlands, Sweden, the United Kingdom) coastal remains confirms this, with whaling the possible cause.[25] Remains dating from the Roman epoch were found in the Mediterranean during excavation of the antique harbor of Lattara near Montpellier, France, in 1997, raising the question of whether Atlantic gray whales migrated up and down the coast of Europe from Wadden Sea to calve in the Mediterranean.[54][55] A 2018 study utilizing ancient DNA barcoding and collagen peptide matrix fingerprinting confirmed that Roman era whale bones east of the Strait of Gibraltar were gray whales (and North Atlantic right whales), confirming that gray whales once ranged into the Mediterranean.[56] Similarly, radiocarbon dating of American east coastal subfossil remains confirm that gray whales existed there at least through the 17th century. This population ranged at least from Southampton, New York, to Jupiter Island, Florida, the latest from 1675.[24] In his 1835 history of Nantucket Island, Obed Macy wrote that in the early pre-1672 colony a whale of the kind called "scragg" entered the harbor and was pursued and killed by the settlers.[57] A. B. Van Deinse points out that the "scrag whale", described by P. Dudley in 1725 as one of the species hunted by the early New England whalers, was almost certainly the gray whale.[58][59]

During the 2010s there have been rare sightings of gray whales in the North Atlantic Ocean or the connecting Mediterranean Sea, including one off the coast of Israel and one off the coast of Namibia.[60][61] These apparently were migrants from the North Pacific population through the Arctic Ocean.[60][61] A 2015 study of DNA from subfossil gray whales indicated that this may not be a historically unique event.[60][61][62] That study suggested that over the past 100,000 years there have been several migrations of gray whales between the Pacific and Atlantic, with the most recent large scale migration of this sort occurring about 5000 years ago.[60][61][62] These migrations corresponded to times of relatively high temperatures in the Arctic Ocean.[60][61][62] In 2021, one individual was seen at Rabat, Morocco,[63] followed by sightings at Algeria[64] and Italy.[65]

Prewhaling abundance

Researchers[66] used a genetic approach to estimate pre-whaling abundance based on samples from 42 California gray whales, and reported DNA variability at 10 genetic loci consistent with a population size of 76,000–118,000 individuals, three to five times larger than the average census size as measured through 2007. NOAA has collected surveys of gray whale population since at least the 1960s.[67] They state that "the most recent population estimate [from 2007] was approximately 19,000 whales, with a high probability (88%) that the population is at 'optimum sustainable population' size, as defined by the Marine Mammal Protection Act. They speculate that the ocean ecosystem has likely changed since the prewhaling era, making a return to prewhaling numbers infeasible.[68] Factors limiting or threatening current population levels include ship strikes, entanglement in fishing gear, and changes in sea-ice coverage associated with climate change.[69]

Integration and recolonization

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Calf with mouth open showing baleen, Alaska

Several whales seen off Sakhalin and on Kamchatka Peninsula are confirmed to migrate towards eastern side of Pacific and join the larger eastern population. In January 2011, a gray whale that had been tagged in the western population was tracked as far east as the eastern population range off the coast of British Columbia.[70] Recent findings from either stranded or entangled specimens indicate that the original western population have become functionally extinct and possibly all the whales appeared on Japanese and Chinese coasts in modern times are vagrants or re-colonizers from the eastern population.[39][42]

In mid-1980, there were three gray whale sightings in the eastern Beaufort Sea, placing them 585 kilometers (364 mi) further east than their known range at the time.[71] Recent increases in sightings are confirmed in Arctic areas of the historic range for Atlantic stocks, most notably on several locations in the Laptev Sea including the New Siberian Islands in the East Siberian Sea,[72] and around the marine mammal sanctuary[73] of the Franz Josef Land,[74] indicating possible earlier pioneers of re-colonizations. These whales were darker in body color than those whales seen in Sea of Okhotsk.[41] In May 2010, a gray whale was sighted off the Mediterranean shore of Israel.[75] It has been speculated that this whale crossed from the Pacific to the Atlantic via the Northwest Passage, since an alternative route around Cape Horn would not be contiguous to the whale's established territory. There has been gradual melting and recession of Arctic sea ice with extreme loss in 2007 rendering the Northwest Passage "fully navigable".[76] The same whale was sighted again on May 30, 2010, off the coast of Barcelona, Spain.[77]

In May 2013, a gray whale was sighted off Walvis Bay, Namibia. Scientists from the Namibian Dolphin Project confirmed the whale's identity and thus provides the only sighting of this species in the Southern Hemisphere. Photographic identification suggests that this is a different individual than the one spotted in the Mediterranean in 2010. As of July 2013, the Namibian whale was still being seen regularly.[78]

In March 2021, a gray whale was sighted near Rabat, the capital of Morocco.[63] In April, additional sightings were made off Algeria[64] and Italy.[65]

Genetic analysis of fossil and prefossil gray whale remains in the Atlantic Ocean suggests several waves of dispersal from the Pacific to the Atlantic related to successive periods of climactic warming – during the Pleistocene before the last glacial period and the early Holocene immediately following the opening of the Bering Strait. This information and the recent sightings of Pacific gray whales in the Atlantic, suggest that another range expansion to the Atlantic may be starting.[79]

Life history

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A whale swims off the coast near the Santa Monica Mountains.

Reproduction

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Embryos of gray whale (1874 illustration) and outline of head showing spouthole

Breeding behavior is complex and often involves three or more animals. Both male and female whales reach puberty between the ages of 6 and 12 with an average of eight to nine years.[80] Females show highly synchronized reproduction, undergoing oestrus in late November to early December.[81] During the breeding season, it is common for females to have several mates.[82] This single ovulation event is believed to coincide with the species' annual migration patterns, when births can occur in warmer waters.[82] Most females show biennial reproduction, although annual births have been reported.[81] Males also show seasonal changes, experiencing an increase in testes mass that correlates with the time females undergo oestrus.[82] Currently there are no accounts of twin births, although an instance of twins in utero has been reported.[81]

The gestation period for gray whales is approximately 13 12 months, with females giving birth every one to three years.[80][83] In the latter half of the pregnancy, the fetus experiences a rapid growth in length and mass. Similar to the narrow breeding season, most calves are born within a six-week time period in mid January.[80] The calf is born tail first, and measures about 14–16 ft in length, and a weight of 2,000 lbs.[8] Females lactate for approximately seven months following birth, at which point calves are weaned and maternal care begins to decrease.[80] The shallow lagoon waters in which gray whales reproduce are believed to protect the newborn from sharks and orcas.[84][44]

On 7 January 2014, a pair of newborn or aborted conjoined twin gray whale calves were found dead in the Laguna Ojo de Liebre (Scammon's Lagoon), off the west coast of Mexico. They were joined by their bellies.[85]

Feeding

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Gray whale breaching off the coast of Santa Barbara, California

The whale feeds mainly on benthic crustaceans, which it eats by turning on its side and scooping up sediments from the sea floor. This unique feeding selection makes gray whales one of the most strongly reliant on coastal waters among baleen whales. It is classified as a baleen whale and has baleen, or whalebone, which acts like a sieve, to capture small sea animals, including amphipods taken in along with sand, water and other material. Off Vancouver Island, gray whales commonly feed on shrimp-like mysids. When mysids are abundant gray whales are present in fairly large numbers. Despite mysids being a prey of choice, gray whales are opportunistic feeders and can easily switch from feeding planktonically to benthically. When gray whales feed planktonically, they roll onto their right side while their fluke remains above the surface, or they apply the skimming method seen in other baleen whales (skimming the surface with their mouth open). This skimming behavior mainly seems to be used when gray whales are feeding on crab larvae. Gray whales feed benthically, by diving to the ocean floor and rolling on to their side, (gray whales, like blue whales seem to favor rolling onto their right side) and suck up prey from the sea floor.[86] Gray whales seem to favor feeding planktonically in their feeding grounds, but benthically along their migration route in shallower water.[87] Mostly, the animal feeds in the northern waters during the summer; and opportunistically feeds during its migration, depending primarily on its extensive fat reserves. Another reason for this opportunistic feeding may be the result of population increases, resulting in the whales taking advantage of whatever prey is available, due to increased competition.[88] Feeding areas during migration seem to include the Gulf of California, Monterey Bay and Baja California Sur.[89] Calf gray whales drink 50–80 lb (23–36 kg) of their mothers' 53% fat milk per day.[90]

The main feeding habitat of the western Pacific subpopulation is the shallow (5–15 m (16–49 ft) depth) shelf off northeastern Sakhalin Island, particularly off the southern portion of Piltun Lagoon, where the main prey species appear to be amphipods and isopods.[91] In some years, the whales have also used an offshore feeding ground in 30–35 m (98–115 ft) depth southeast of Chayvo Bay, where benthic amphipods and cumaceans are the main prey species.[92] Some gray whales have also been seen off western Kamchatka, but to date all whales photographed there are also known from the Piltun area.[47][93]

Feeding mechanism of Eschrichtius robustus.svg

Diagram of the gray whale seafloor feeding strategy

A gray whale feeding near Yaquina Head, Oregon
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A gray whale viewed from above

Migration

Predicted distribution models indicate that overall range in the last glacial period was broader or more southerly distributed, and inhabitations in waters where species presences lack in present situation, such as in southern hemisphere and south Asian waters and northern Indian Ocean were possible due to feasibility of the environment on those days.[79] Range expansions due to recoveries and re-colonization in the future is likely to be happen and the predicted range covers wider than that of today. The gray whale undergoes the longest migration of any mammal.[94]

Eastern Pacific population

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A gray whale breaching in a lagoon on the coast of Mexico

Each October, as the northern ice pushes southward, small groups of eastern gray whales in the eastern Pacific start a two- to three-month, 8,000–11,000 km (5,000–6,800 mi) trip south. Beginning in the Bering and Chukchi seas and ending in the warm-water lagoons of Mexico's Baja California Peninsula and the southern Gulf of California, they travel along the west coast of Canada, the United States and Mexico.[95]

Traveling night and day, the gray whale averages approximately 120 km (75 mi) per day at an average speed of 8 km/h (5 mph). This round trip of 16,000–22,000 km (9,900–13,700 mi) is believed to be the longest annual migration of any mammal.[96] By mid-December to early January, the majority are usually found between Monterey and San Diego such as at Morro bay, often visible from shore.[94] The whale watching industry provides ecotourists and marine mammal enthusiasts the opportunity to see groups of gray whales as they migrate.

By late December to early January, eastern grays begin to arrive in the calving lagoons and bays on the west coast of Baja California Sur. The three most popular are San Ignacio, Magdalena Bay to the south, and, to the north, Laguna Ojo de Liebre (formerly known in English as Scammon's Lagoon after whaleman Charles Melville Scammon, who discovered the lagoons in the 1850s and hunted the grays).[97][98]

Gray whales once ranged into Sea of Cortez and Pacific coasts of continental Mexico south to the Islas Marías, Bahía de Banderas, and Nayarit/Jalisco, and there were two modern calving grounds in Sonora (Tojahui or Yavaros) and Sinaloa (Bahia Santa Maria, Bahia Navachiste, La Reforma, Bahia Altata) until being abandoned in 1980s.[99][100]

These first whales to arrive are usually pregnant mothers looking for the protection of the lagoons to bear their calves, along with single females seeking mates. By mid-February to mid-March, the bulk of the population has arrived in the lagoons, filling them with nursing, calving and mating gray whales.

Throughout February and March, the first to leave the lagoons are males and females without new calves. Pregnant females and nursing mothers with their newborns are the last to depart, leaving only when their calves are ready for the journey, which is usually from late March to mid-April. Often, a few mothers linger with their young calves well into May. Whale watching in Baja's lagoons is particularly popular because the whales often come close enough to boats for tourists to pet them.[101]

By late March or early April, the returning animals can be seen from Puget Sound to Canada.

Resident groups
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A gray whale swims near surf on Nootka Island within residential range.

A population of about 200 gray whales stay along the eastern Pacific coast from Canada to California throughout the summer, not making the farther trip to Alaskan waters. This summer resident group is known as the Pacific Coast feeding group.[102]

Any historical or current presence of similar groups of residents among the western population is currently unknown, however, whalers' logbooks and scientific observations indicate that possible year-round occurrences in Chinese waters and Yellow and Bohai basins were likely to be summering grounds.[103][104] Some of the better documented historical catches show that it was common for whales to stay for months in enclosed waters elsewhere, with known records in the Seto Inland Sea[105] and the Gulf of Tosa. Former feeding areas were once spread over large portions on mid-Honshu to northern Hokkaido, and at least whales were recorded for majority of annual seasons including wintering periods at least along east coasts of Korean Peninsula and Yamaguchi Prefecture.[104] Some recent observations indicate that historic presences of resident whales are possible: a group of two or three were observed feeding in Izu Ōshima in 1994 for almost a month,[106] two single individuals stayed in Ise Bay for almost two months in the 1980s and in 2012, the first confirmed living individuals in Japanese EEZ in the Sea of Japan and the first of living cow-calf pairs since the end of whaling stayed for about three weeks on the coastline of Teradomari in 2014.[107][108] One of the pair returned to the same coasts at the same time of the year in 2015 again.[109] Reviewing on other cases on different locations among Japanese coasts and islands observed during 2015 indicate that spatial or seasonal residencies regardless of being temporal or permanental staying once occurred throughout many parts of Japan or on other coastal Asia.[110]

Western population

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A gray whale in the water off Sakhalin Island.

The current western gray whale population summers in the Sea of Okhotsk, mainly off Piltun Bay region at the northeastern coast of Sakhalin Island (Russian Federation). There are also occasional sightings off the eastern coast of Kamchatka (Russian Federation) and in other coastal waters of the northern Okhotsk Sea.[91][111] Its migration routes and wintering grounds are poorly known, the only recent information being from occasional records on both the eastern and western coasts of Japan[112] and along the Chinese coast.[113] Gray whale had not been observed on Commander Islands until 2016.[114] The northwestern pacific population consists of approximately 300 individuals, based on photo identification collected off of Sakhalin Island and Kamchatka.[8]

The Sea of Japan was once thought not to have been a migration route, until several entanglements were recorded.[115] Any records of the species had not been confirmed since after 1921 on Kyushu.[104] However, there were numerous records of whales along the Genkai Sea off Yamaguchi Prefecture,[116] in Ine Bay in the Gulf of Wakasa, and in Tsushima. Gray whales, along with other species such as right whales and Baird's beaked whales, were common features off the north eastern coast of Hokkaido near Teshio, Ishikari Bay near Otaru, the Shakotan Peninsula, and islands in the La Pérouse Strait such as Rebun Island and Rishiri Island. These areas may also have included feeding grounds.[104] There are shallow, muddy areas favorable for feeding whales off Shiretoko, such as at Shibetsu, the Notsuke Peninsula, Cape Ochiishi on Nemuro Peninsula, Mutsu Bay,[117] along the Tottori Sand Dunes, in the Suou-nada Sea, and Ōmura Bay.

The historical calving grounds were unknown but might have been along southern Chinese coasts from Zhejiang and Fujian Province to Guangdong, especially south of Hailing Island[103] and to near Hong Kong. Possibilities include Daya Bay, Wailou Harbour on Leizhou Peninsula, and possibly as far south as Hainan Province and Guangxi, particularly around Hainan Island. These areas are at the southwestern end of the known range.[47][118] It is unknown whether the whales' normal range once reached further south, to the Gulf of Tonkin. In addition, the existence of historical calving ground on Taiwan and Penghu Islands (with some fossil records[119] and captures[120]), and any presence in other areas outside of the known ranges off Babuyan Islands in Philippines and coastal Vietnamese waters in Gulf of Tonkin are unknown. There is only one confirmed record of accidentally killing of the species in Vietnam, at Ngoc Vung Island off Ha Long Bay in 1994 and the skeleton is on exhibition at the Quang Ninh Provincial Historical Museum.[121][122] Gray whales are known to occur in Taiwan Strait even in recent years.[123]

It is also unknown whether any winter breeding grounds ever existed beyond Chinese coasts. For example, it is not known if the whales visited the southern coasts of the Korean Peninsula, adjacent to the Island of Jeju), Haiyang Island, the Gulf of Shanghai, or the Zhoushan Archipelago.[124] There is no evidence of historical presence in Japan south of Ōsumi Peninsula;[125] only one skeleton has been discovered in Miyazaki Prefecture.[126] Hideo Omura once considered the Seto Inland Sea to be a historical breeding ground, but only a handful of capture records support this idea, although migrations into the sea have been confirmed. Recent studies using genetics and acoustics, suggest that there are several wintering sites for western gray whales such as Mexico and the East China sea. However, their wintering ground habits in the western North Pacific are still poorly understood and additional research is needed.[105]

Recent migration in Asian waters

Even though South Korea put the most effort into conservation of the species among the Asian nations, there are no confirmed sightings along the Korean Peninsula or even in the Sea of Japan in recent years.

The last confirmed record in Korean waters was the sighting of a pair off Bangeojin, Ulsan in 1977.[127] Prior to this, the last was of catches of 5 animals[128] off Ulsan in 1966.[103] There was a possible sighting of a whale within the port of Samcheok in 2015.[129]

There had been 24 records along Chinese coasts including sighting, stranding, intended hunts, and bycatches since 1933.[42] The last report of occurrence of the species in Chinese waters was of a stranded semi adult female in the Bohai Sea in 1996,[103] and the only record in Chinese waters in the 21st century was of a fully-grown female being killed by entanglement in Pingtan, China in November, 2007.[123] DNA studies indicated that this individual might have originated from the eastern population rather than the western.[42]

Most notable observations of living whales after the 1980s were of 17 or 18 whales along Primorsky Krai in late October, 1989 (prior to this, a pair was reported swimming in the area in 1987), followed by the record of 14 whales in La Pérouse Strait on 13th, June in 1982 (in this strait, there was another sighting of a pair in October, 1987).[104] In 2011, presences of gray whales were acoustically detected among pelagic waters in East China Sea between Chinese and Japanese waters.[130]

Since the mid 1990s, almost all the confirmed records of living animals in Asian waters were from Japanese coasts.[131] There have been eight to fifteen sightings and stray records including unconfirmed sightings and re-sightings of the same individual, and one later killed by net-entanglement. The most notable of these observations are listed below:

  • The feeding activities of a group of two or three whales that stayed around Izu Ōshima in 1994 for almost a month were recorded underwater[106] by several researchers and whale photographers.[132]
  • A pair of thin juveniles were sighted off Kuroshio, Kōchi, a renowned town for whale-watching tourism of resident and sub-resident populations of Bryde's whales, in 1997.[133] This sighting was unusual because of the location on mid-latitude in summer time.
  • Another pair of sub-adults were confirmed swimming near the mouth of Otani River in Suruga Bay in May, 2003.[117]
  • A sub-adult whale that stayed in the Ise and Mikawa Bay for nearly two months in 2012[134][135][136] was later confirmed to be the same individual as the small whale observed off Tahara near Cape Irago in 2010,[137] making it the first confirmed constant migration out of Russian waters. The juvenile observed off Owase in Kumanonada Sea in 2009 might or might not be the same individual. The Ise and Mikawa Bay region is the only location along Japanese coasts that has several records since the 1980s (a mortal entanglement in 1968, above mentioned short-stay in 1982, self-freeing entanglement in 2005),[105][133] and is also the location where the first commercial whaling started. Other areas with several sighting or stranding records in recent years are off the Kumanonada Sea in Wakayama, off Oshika Peninsula in Tōhoku, and on coastlines close to Tomakomai, Hokkaido.
  • Possibly the first confirmed record of living animals in Japanese waters in the Sea of Japan since the end of whaling occurred on 3 April 2014 at Nodumi Beach, Teradomari, Niigata.[138][139][140] Two individuals, measuring ten and five metres respectively, stayed near the mouth of Shinano River for three weeks.[39] It is unknown whether this was a cow-calf pair, which would have been a first record in Asia. All of the previous modern records in the Sea of Japan were of by-catches.[115]
  • One of the above pair returned on the same beaches at the same time of a year in 2015.[109][141]
  • A juvenile or possibly or not with another larger individual remained in Japanese waters between January or March and May 2015.[142] It was first confirmed occurrences of the species on remote, oceanic islands in Japan. One or more visited waters firstly on Kōzu-shima and Nii-Jima for weeks then adjacent to Miho no Matsubara and behind the Tokai University campus for several weeks.[143] Possibly the same individual was seen off Futo as well.[144] This later was identified as the same individual previously recorded on Sakhalin in 2014, the first re-recording one individual at different Asian locations.[110]
  • A young whale was observed by land-based fishermen at Cape Irago in March, 2015.[145]
  • One of the above pair appeared in 2015 off southeastern Japan and then reappeared off Tateyama in January, 2016.[146] The identity of this whale was confirmed by Nana Takanawa who photographed the same whale on Niijima in 2015.[147] Likely the same individual was sighted off Futo[144] and half an hour later off Akazawa beach in Itō, Shizuoka on the 14th.[148][149][150] The whale then stayed next to a pier on Miyake-jima and later at Habushi beach on Niijima, the same beach the same individual stayed near on the previous year.
  • One whale of 9 metres (30 ft) was beached nearby Wadaura on March 4, 2016.[151] Investigations on the corpse indicate that this was likely a different individual from the above animal.
  • A 7 metres (23 ft) carcass of young female was firstly reported floating along Atami on 4 April then was washed ashore on Ito on the 6th.[152]
  • As of April 20, 2017, one or more whale(s) have been staying within Tokyo Bay since February although at one point another whale if or if not the same individual sighted off Hayama, Kanagawa.[153][154] It is unclear the exact number of whales included in these sightings; two whales reported by fishermen and Japanese coastal guard reported three whales on 20th or 21st.[155]

Whaling

North Pacific

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Charles Melville Scammon's 1874 illustration of a gray whale

Eastern population

Humans and orcas are the adult gray whale's only predators, although orcas are the more prominent predator.[156] Aboriginal hunters, including those on Vancouver Island and the Makah in Washington, have hunted gray whales.

Commercial whaling by Europeans of the species in the North Pacific began in the winter of 1845–46, when two United States ships, the Hibernia and the United States, under Captains Smith and Stevens, caught 32 in Magdalena Bay. More ships followed in the two following winters, after which gray whaling in the bay was nearly abandoned because "of the inferior quality and low price of the dark-colored gray whale oil, the low quality and quantity of whalebone from the gray, and the dangers of lagoon whaling."[157]

Gray whaling in Magdalena Bay was revived in the winter of 1855–56 by several vessels, mainly from San Francisco, including the ship Leonore, under Captain Charles Melville Scammon. This was the first of 11 winters from 1855 through 1865 known as the "bonanza period", during which gray whaling along the coast of Baja California reached its peak. Not only were the whales taken in Magdalena Bay, but also by ships anchored along the coast from San Diego south to Cabo San Lucas and from whaling stations from Crescent City in northern California south to San Ignacio Lagoon. During the same period, vessels targeting right and bowhead whales in the Gulf of Alaska, Sea of Okhotsk, and the Western Arctic would take the odd gray whale if neither of the more desirable two species were in sight.[157]

In December 1857, Charles Scammon, in the brig Boston, along with his schooner-tender Marin, entered Laguna Ojo de Liebre (Jack-Rabbit Spring Lagoon) or later known as Scammon's Lagoon (by 1860) and found one of the gray's last refuges. He caught 20 whales.[157] He returned the following winter (1858–59) with the bark Ocean Bird and schooner tenders A.M. Simpson and Kate. In three months, he caught 47 cows, yielding 1,700 barrels (270 m3) of oil.[158] In the winter of 1859–60, Scammon, again in the bark Ocean Bird, along with several other vessels, entered San Ignacio Lagoon to the south where he discovered the last breeding lagoon. Within only a couple of seasons, the lagoon was nearly devoid of whales.[157]

Between 1846 and 1874, an estimated 8,000 gray whales were killed by American and European whalemen, with over half having been killed in the Magdalena Bay complex (Estero Santo Domingo, Magdalena Bay itself, and Almejas Bay) and by shore whalemen in California and Baja California.[157]

 src=
Spyhopping off the Alaskan coast

A second, shorter, and less intensive hunt occurred for gray whales in the eastern North Pacific. Only a few were caught from two whaling stations on the coast of California from 1919 to 1926, and a single station in Washington (1911–21) accounted for the capture of another. For the entire west coast of North America for the years 1919 to 1929, 234 gray whales were caught. Only a dozen or so were taken by British Columbian stations, nearly all of them in 1953 at Coal Harbour.[159] A whaling station in Richmond, California, caught 311 gray whales for "scientific purposes" between 1964 and 1969. From 1961 to 1972, the Soviet Union caught 138 gray whales (they originally reported not having taken any). The only other significant catch was made in two seasons by the steam-schooner California off Malibu, California. In the winters of 1934–35 and 1935–36, the California anchored off Point Dume in Paradise Cove, processing gray whales. In 1936, gray whales became protected in the United States.[160]

Western population

The Japanese began to catch gray whales beginning in the 1570s. At Kawajiri, Nagato, 169 gray whales were caught between 1698 and 1889. At Tsuro, Shikoku, 201 were taken between 1849 and 1896.[161] Several hundred more were probably caught by American and European whalemen in the Sea of Okhotsk from the 1840s to the early 20th century.[162] Whalemen caught 44 with nets in Japan during the 1890s. The real damage was done between 1911 and 1933, when Japanese whalemen killed 1,449 after Japanese companies established several whaling stations on Korean Peninsula and on Chinese coast such as near the Daya bay and on Hainan Island. By 1934, the western gray whale was near extinction. From 1891 to 1966, an estimated 1,800–2,000 gray whales were caught, with peak catches of between 100 and 200 annually occurring in the 1910s.[162]

As of 2001, the Californian gray whale population had grown to about 26,000. As of 2016, the population of western Pacific (seas near Korea, Japan, and Kamchatka) gray whales was an estimated 200.[43]

North Atlantic

The North Atlantic population may have been hunted to extinction in the 18th century. Circumstantial evidence indicates whaling could have contributed to this population's decline, as the increase in whaling activity in the 17th and 18th centuries coincided with the population's disappearance.[24] A. B. Van Deinse points out the "scrag whale", described by P. Dudley in 1725, as one target of early New England whalers, was almost certainly the gray whale.[58][59] In his 1835 history of Nantucket Island, Obed Macy wrote that in the early pre-1672 colony, a whale of the kind called "scragg" entered the harbor and was pursued and killed by the settlers.[57] Gray whales (Icelandic sandlægja) were described in Iceland in the early 17th century.[163] Formations of industrial whaling among the Mediterranean basin(s) have been considered to be feasible as well.[55]

Conservation

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Joint American-Russian freeing effort of whales entrapped by ice floe in Beaufort Sea.

Gray whales have been granted protection from commercial hunting by the International Whaling Commission (IWC) since 1949, and are no longer hunted on a large scale.

Limited hunting of gray whales has continued since that time, however, primarily in the Chukotka region of northeastern Russia, where large numbers of gray whales spend the summer months. This hunt has been allowed under an "aboriginal/subsistence whaling" exception to the commercial-hunting ban. Anti-whaling groups have protested the hunt, saying the meat from the whales is not for traditional native consumption, but is used instead to feed animals in government-run fur farms; they cite annual catch numbers that rose dramatically during the 1940s, at the time when state-run fur farms were being established in the region. Although the Soviet government denied these charges as recently as 1987, in recent years the Russian government has acknowledged the practice. The Russian IWC delegation has said that the hunt is justified under the aboriginal/subsistence exemption, since the fur farms provide a necessary economic base for the region's native population.[164]

Currently, the annual quota for the gray whale catch in the region is 140 per year. Pursuant to an agreement between the United States and Russia, the Makah tribe of Washington claimed four whales from the IWC quota established at the 1997 meeting. With the exception of a single gray whale killed in 1999, the Makah people have been prevented from hunting by a series of legal challenges, culminating in a United States federal appeals court decision in December 2002 that required the National Marine Fisheries Service to prepare an Environmental Impact Statement. On September 8, 2007, five members of the Makah tribe shot a gray whale using high-powered rifles in spite of the decision. The whale died within 12 hours, sinking while heading out to sea.[165]

As of 2018, the IUCN regards the gray whale as being of least concern from a conservation perspective. However, the specific subpopulation in the northwest Pacific is regarded as being critically endangered.[3] The northwest Pacific population is also listed as endangered by the U.S. government's National Marine Fisheries Service under the U.S. Endangered Species Act. The IWC Bowhead, Right and Gray Whale subcommittee in 2011 reiterated the conservation risk to western gray whales is large because of the small size of the population and the potential anthropogenic impacts.[46]

Gray whale migrations off of the Pacific Coast were observed, initially, by Marineland of the Pacific in Palos Verdes, California. The Gray Whale Census, an official gray whale migration census that has been recording data on the migration of the Pacific gray whale has been keeping track of the population of the Pacific gray whale since 1985. This census is the longest running census of the Pacific gray whale. Census keepers volunteer from December 1 through May, from sun up to sun down, seven days a week, keeping track of the amount of gray whales migrating through the area off of Los Angeles. Information from this census is listed through the American Cetacean Society of Los Angeles (ACSLA).

South Korea and China list gray whales as protected species of high concern. In South Korea, the Gray Whale Migration Site[166] was registered as the 126th national monument in 1962,[167] although illegal hunts have taken place thereafter,[128] and there have been no recent sightings of the species in Korean waters.

Rewilding proposal

In 2005, two conservation biologists proposed a plan to airlift 50 gray whales from the Pacific Ocean to the Atlantic Ocean. They reasoned that, as Californian gray whales had replenished to a suitable population, surplus whales could be transported to repopulate the extinct British population.[168][169] As of 2017 this plan has not been undertaken.[170]

Threats

According to the Government of Canada's Management Plan for gray whales, threats to the eastern North Pacific population of gray whales include:[171] increased human activities in their breeding lagoons in Mexico, climate change, acute noise, toxic spills, aboriginal whaling, entanglement with fishing gear, boat collisions, and possible impacts from fossil fuel exploration and extraction.

Western gray whales are facing, the large-scale offshore oil and gas development programs near their summer feeding ground, as well as fatal net entrapments off Japan during migration, which pose significant threats to the future survival of the population.[46] The substantial nearshore industrialization and shipping congestion throughout the migratory corridors of the western gray whale population represent potential threats by increasing the likelihood of exposure to ship strikes, chemical pollution, and general disturbance.[47][162]

Offshore gas and oil development in the Okhotsk Sea within 20 km (12 mi) of the primary feeding ground off northeast Sakhalin Island is of particular concern. Activities related to oil and gas exploration, including geophysical seismic surveying, pipelaying and drilling operations, increased vessel traffic, and oil spills, all pose potential threats to western gray whales. Disturbance from underwater industrial noise may displace whales from critical feeding habitat. Physical habitat damage from drilling and dredging operations, combined with possible impacts of oil and chemical spills on benthic prey communities also warrants concern. The western gray whale population is considered to be endangered according to IUCN standards.[47][93]

Along Japanese coasts, four females including a cow-calf pair were trapped and killed in nets in the 2000s. There had been a record of dead whale thought to be harpooned by dolphin-hunters found on Hokkaido in the 1990s.[47][172] Meats for sale were also discovered in Japanese markets as well.[173]

2019 has had a record number of gray whale strandings and deaths, with their being 122 strandings in United States waters and 214 in Canadian waters. The cause of death in some specimens appears to be related to poor nutritional condition.[174] It is hypothesized that some of these strandings are related to changes in prey abundance or quality in the Arctic feeding grounds, resulting in poor feeding. Some scientists suggest that the lack of sea ice has been preventing the fertilization of amphipods, a main source of food for gray whales, so that they have been hunting krill instead, which is far less nutritious. More research needs to be conducted to understand this issue.[175]

A recent study provides some evidence that solar activity is correlated to gray whale strandings. When there was a high prevalence of sunspots, gray whales were five times more likely to strand. A possible explanation for this phenomenon is that solar storms release a large amount of electromagnetic radiation, which disrupts earth's magnetic field and/or the whale's ability to analyze it.[176] This may apply to the other species of cetaceans, such as sperm whales.[177] However, there is not enough evidence to suggest that whales navigate through the use of magnetoreception (an organisms' ability to sense a magnetic field).

Orcas are "a prime predator of gray whale calves."[44] Typically three to four orcas ram a calf from beneath in order to separate it from its mother, who defends it. Humpback whales have been observed defending gray whale calves from orcas.[44] Orcas will often arrive in Monterey Bay to intercept gray whales during their northbound migration, targeting females migrating with newborn calves. They will separate the calf from the mother and hold the calf under water to drown it. The tactic of holding whales under water to drown them is certainly used by orcas on adult gray whales as well.[178] It is roughly estimated that 33% of the gray whales born in a given year might be killed by predation.[179]

Captivity

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A gray whale in captivity

Because of their size and need to migrate, gray whales have rarely been held in captivity, and then only for brief periods of time. The first captive gray whale, who was captured in Scammon's Lagoon, Baja California in 1965, was named Gigi and died two months later from an infection.[180] The second gray whale, who was captured in 1972 from the same lagoon, was named Gigi II and was released a year later after becoming too large for the facilities.[181] The third gray whale, J.J., first beached herself in Marina del Rey, California where she was rushed to SeaWorld San Diego. After 14 months, she was released because she also grew too large to be cared for in the existing facilities. At 19,200 pounds (8,700 kg) and 31 feet (9.4 m) when she was released, J.J. was the largest marine mammal ever to be kept in captivity.[182]

See also

References

  1. ^ a b Mead, J.G.; Brownell, R. L. Jr. (2005). "Order Cetacea". In Wilson, D.E.; Reeder, D.M (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. pp. 723–743. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. ^ Boessenecker, Robert (2007). "New records of fossil fur seals and walruses (Carnivora: Pinnipedia) from the late Neogene of Northern California". Journal of Vertebrate Paleontology. 27: 50A.
  3. ^ a b Cooke, J.G. (2018). "Eschrichtius robustus". IUCN Red List of Threatened Species. 2018: e.T8097A50353881. doi:10.2305/IUCN.UK.2018-2.RLTS.T8097A50353881.en. Retrieved 19 November 2021.
  4. ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  5. ^ Britannica Micro.: v. IV, p. 693.
  6. ^ Nowak, Ronald M. (7 April 1999). Walker's Mammals of the World. JHU Press. p. 1132. ISBN 978-0-8018-5789-8.
  7. ^ Recovery Strategy for the Grey Whale (Eschrichtius robustus), Atlantic Population, in Canada. Dsp-psd.pwgsc.gc.ca (2012-07-31). Retrieved on 2012-12-20.
  8. ^ a b c Fisheries, NOAA (2020-06-25). "Gray Whale | NOAA Fisheries". NOAA. Retrieved 2020-06-29.
  9. ^ Gray Whale Eschrichtius robustus. American Cetacean Society
  10. ^ Gray Whale. Worldwildlife.org. Retrieved on 2012-12-20.
  11. ^ Perrin, William F.; Würsig, Bernd G.; Thewissen, J. G. M. (2009). Encyclopedia of marine mammals. Academic Press. p. 404. ISBN 978-0-12-373553-9.
  12. ^ The Paleobiology Database Eschrichtiidae entry accessed on 26 December 2010
  13. ^ Kimura, T.; Hasegawa, Y.; Kohno, N. (2017). "A new species of the genus Eschrichtius (Cetacea: Mysticeti) from the Early Pleistocene of Japan". Paleontological Research. 22 (1): 1–19. doi:10.2517/2017PR007. S2CID 134494152.
  14. ^ Seeman, Mette E.; et al. (December 2009). "Radiation of extant cetaceans driven by restructuring of the ocean". Systematic Biology. 58 (6): 573–585. doi:10.1093/sysbio/syp060. JSTOR 25677547. PMC 2777972. PMID 20525610.
  15. ^ Arnason, U.; Gullberg A. & Widegren, B. (1993). "Cetacean mitochondrial DNA control region: sequences of all extant baleen whales and two sperm whale species". Molecular Biology and Evolution. 10 (5): 960–970. doi:10.1093/oxfordjournals.molbev.a040061. PMID 8412655.
  16. ^ Sasaki, T.; Nikaido, Masato; Hamilton, Healy; Goto, Mutsuo; Kato, Hidehiro; Kanda, Naohisa; Pastene, Luis; Cao, Ying; et al. (2005). "Mitochondrial phylogenetics and evolution of mysticete whales". Systematic Biology. 54 (1): 77–90. doi:10.1080/10635150590905939. PMID 15805012.
  17. ^ McGowen, Michael R; Tsagkogeorga, Georgia; Álvarez-Carretero, Sandra; dos Reis, Mario; Struebig, Monika; Deaville, Robert; Jepson, Paul D; Jarman, Simon; Polanowski, Andrea; Morin, Phillip A; Rossiter, Stephen J (2019-10-21). "Phylogenomic Resolution of the Cetacean Tree of Life Using Target Sequence Capture". Systematic Biology. 69 (3): 479–501. doi:10.1093/sysbio/syz068. ISSN 1063-5157. PMC 7164366. PMID 31633766.
  18. ^ Árnason, Úlfur; Lammers, Fritjof; Kumar, Vikas; Nilsson, Maria A.; Janke, Axel (2018). "Whole-genome sequencing of the blue whale and other rorquals finds signatures for introgressive gene flow". Science Advances. 4 (4): eaap9873. Bibcode:2018SciA....4.9873A. doi:10.1126/sciadv.aap9873. PMC 5884691. PMID 29632892.
  19. ^ "Explore the Database". www.mammaldiversity.org. Retrieved 2021-08-20.
  20. ^ Gray (1864). "Eschrichtius". Annals and Magazine of Natural History. 3 (14): 350.
  21. ^ Pyenson, Nicholas D.; Lindberg, David R. (2011). Goswami, Anjali (ed.). "What happened to gray whales during the Pleistocene? The ecological impact of sea-level change on benthic feeding areas in the North Pacific Ocean". PLOS ONE. 6 (7): e21295. Bibcode:2011PLoSO...621295P. doi:10.1371/journal.pone.0021295. PMC 3130736. PMID 21754984.
  22. ^ Cope (1869). "Rhachianectes". Proceedings of the Academy of Natural Sciences of Philadelphia. 21: 15.
  23. ^ Cederlund, BA (1938). "A subfossil gray whale discovered in Sweden in 1859". Zoologiska Bidrag från Uppsala. 18: 269–286.
  24. ^ a b c Mead JG, Mitchell ED (1984). "Atlantic gray whales". In Jones ML, Swartz SL, Leatherwood S (eds.). The Gray Whale. London: Academic Press. pp. 33–53.
  25. ^ a b Bryant, PJ (1995). "Dating remains of gray whales from the eastern North Atlantic". Journal of Mammalogy. 76 (3): 857–861. doi:10.2307/1382754. JSTOR 1382754.
  26. ^ Waser, Katherine (1998). "Ecotourism and the desert whale: An interview with Dr. Emily Young". Arid Lands Newsletter.
  27. ^ "Eschrichtius robustus". Integrated Taxonomic Information System. Retrieved March 18, 2006.
  28. ^ Erxleben 1777, p. 610 (Balaena gibbosa)
  29. ^ E.g. Erxleben 1777, pp. 610–611; Anderson 1746, p. 201; Brisson 1762, p. 221
  30. ^ a b Barnes & McLeod 1984, pp. 4–5
  31. ^ Dudley 1725, p. 258
  32. ^ Lilljeborg 1861, p. 39
  33. ^ Gray 1864, p. 351
  34. ^ Van Beneden & Gervais 1868, pp. 290–291
  35. ^ Scammon 1874, The marine mammals of the north-western coast of North America
  36. ^ Bryant 1995, pp. 857–859
  37. ^ "How to Spot Whales from Shore | the whale trail". thewhaletrail.org. Retrieved 2017-02-13.
  38. ^ Burnie D. and Wilson D.E. (eds.) (2005) Animal: The Definitive Visual Guide to the World's Wildlife. DK Adult, ISBN 0789477645
  39. ^ a b c Kato H.; Kishiro T.; Nishiwaki S.; Nakamura G.; Bando T.; Yasunaga G.; Sakamoto T.; Miyashita T. (2014). "Status Report of Conservation and Researches on the Western North Pacific Gray Whales in Japan, May 2013 – April 2014 [document SC/65b/BRG12]". Retrieved 2021-08-21. {{cite journal}}: Cite journal requires |journal= (help)
  40. ^ a b Nakamura G.; Kato H. (2014). "日本沿岸域に近年(1990–2005 年)出現したコククジラEschrichtius robustus の骨学的特徴,特に頭骨形状から見た北太平洋西部系群と東部系群交流の可能性" (PDF). 哺乳類科学. The Mammal Society of Japan, Cetacean Research Laboratory in Marine environmental section in the Graduate School of Tokyo University of Marine Science and Technology, J-STAGE. 54 (1): 73–88. Retrieved 2015-01-16.
  41. ^ a b Shpak O. (2011). Observation of the gray whale in the Laptev Sea. Standing expedition of IEE Russian Academy of Sciences.
  42. ^ a b c d Xianyan, Wang; Min, Xu; Fuxing, Wu; Weller, David W.; Xing, Miao; Lang, Aimee R.; Qian, Zhu (2015). "Short Note: Insights from a Gray Whale (Eschrichtius robustus) Bycaught in the Taiwan Strait Off China in 2011". Aquatic Mammals. 41 (3): 327. doi:10.1578/AM.41.3.2015.327.
  43. ^ a b Noaa. (n.d.). Gray Whale. Retrieved February 21, 2020, from https://www.fisheries.noaa.gov/species/gray-whale
  44. ^ a b c d Andrew Lachman (May 8, 2018). "Unusual Number of Killer Whales Sighted". San Jose Mercury-News. Bay Area News Group. p. B1.
  45. ^ a b "Whale Conservation Success Highlighted in IUCN Red List Update". The Maritime Executive. Retrieved 2018-11-25.
  46. ^ a b c "Report of the Scientific Committee, Tromsø, Norway, 30 May to 11 June 2011 Annex F: Sub-Committee on Bowhead, Right and Gray Whale" (PDF). IWC Office. Archived from the original (PDF) on 5 November 2011.
  47. ^ a b c d e f Cooke, J.G.; Taylor, B.L.; Reeves, R. & Brownell Jr., R.L. (2018). "Eschrichtius robustus (western subpopulation)". IUCN Red List of Threatened Species. 2018: e.T8099A50345475. Retrieved 2 June 2021.
  48. ^ "Fin whale, mountain gorilla populations rise amid conservation action". Retrieved 2018-11-25.
  49. ^ Rice DW (1998). Marine Mammals of the World. Systematics and Distribution. Special Publication Number 4. Lawrence, Kansas: The Society for Marine Mammalogy.
  50. ^ Jones L.M..Swartz L.S.. Leatherwood S.. The Gray Whale: Eschrichtius Robustus. "Eastern Atlantic Specimens". pp 41–44. Academic Press. Retrieved on September 5, 2017
  51. ^ Global Biodiversity Information Facility. Occurrence Detail 1322462463. Retrieved on September 21, 2017
  52. ^ Fisheries and Oceans Canada. 2016. Grey Whale (Atlantic population) Eschrichtius robustus. Retrieved on August 15, 2017
  53. ^ "Regional Species Extinctions – Examples of regional species extinctions over the last 1000 years and more" (PDF). Census of Marine Life. Archived from the original (PDF) on 2011-04-25. Retrieved 2014-07-05.
  54. ^ Macé M. (2003). "Did the Gray Whale calve in the Mediterranean?". Lattara. 16: 153–164.
  55. ^ a b The MORSE Project – Ancient whale exploitation in the Mediterranean: species matters Archived 2016-12-20 at the Wayback Machine
  56. ^ Ana S. L. Rodrigues; Anne Charpentier; Darío Bernal-Casasola; Armelle Gardeisen; Carlos Nores; José Antonio Pis Millán; Krista McGrath; Camilla F. Speller (July 11, 2018). "Forgotten Mediterranean calving grounds of grey and North Atlantic right whales: evidence from Roman archaeological records". Proceedings of the Royal Society B. 285 (1882). doi:10.1098/rspb.2018.0961. PMC 6053924. PMID 30051821.
  57. ^ a b Macy O (1835). The History of Nantucket:being a compendious account of the first settlement of the island by the English:together with the rise and progress of the whale fishery, and other historical facts relative to said island and its inhabitants:in two parts. Boston: Hilliard, Gray & Co. ISBN 1-4374-0223-2.
  58. ^ a b Van Deinse, AB (1937). "Recent and older finds of the gray whale in the Atlantic". Temminckia. 2: 161–188.
  59. ^ a b Dudley, P (1725). "An essay upon the natural history of whales". Philosophical Transactions of the Royal Society. 33 (381–391): 256–259. Bibcode:1724RSPT...33..256D. doi:10.1098/rstl.1724.0053. JSTOR 103782. S2CID 186208376.
  60. ^ a b c d e Hamilton, Alex (October 8, 2015). "The Gray Whale Sneaks Back into the Atlantic, Two Centuries Later". WNYC. Retrieved 2019-10-28.
  61. ^ a b c d e Schiffman, Richard (February 25, 2016). "Why Are Gray Whales Moving to the Ocean Next Door?". Discover Magazine. Retrieved 2019-10-28.
  62. ^ a b c Alter, S. Elizabeth; Hofreiter, Michael; et al. (March 9, 2015). "Climate impacts on transocean dispersal and habitat in gray whales from the Pleistocene to 2100". Molecular Ecology. 24 (7): 1510–1522. doi:10.1111/mec.13121. PMID 25753251. S2CID 17313811.
  63. ^ a b SOS Dolfijn, 2021, Grijze walvis gemeld bij Marokko
  64. ^ a b Observation.org, 2021-04-04, Archive – Yasutaka Imai
  65. ^ a b "Ponza, a gray whale sighted for the first time in Italy". Italy24 News English. April 15, 2021.
  66. ^ Alter, SE; Newsome, SD; Palumbi, SR (May 2012). "Pre-Whaling Genetic Diversity and Population Ecology in Eastern Pacific Gray Whales: Insights from Ancient DNA and Stable Isotopes". PLOS ONE. 7 (5): e35039. Bibcode:2012PLoSO...735039A. doi:10.1371/journal.pone.0035039. PMC 3348926. PMID 22590499.
  67. ^ Alter, S. E.; Rynes, E.; Palumbi, S. R. (11 September 2007). "DNA evidence for historic population size and past ecosystem impacts of gray whales". Proceedings of the National Academy of Sciences. 104 (38): 15162–15167. Bibcode:2007PNAS..10415162A. doi:10.1073/pnas.0706056104. PMC 1975855. PMID 17848511.
  68. ^ "Gray Whale Population Studies". NOAA, National Marine Fisheries Service, Southwest Fisheries Science Center, Protected Resource Division. 2010. Retrieved 2011-02-25.
  69. ^ "Automatic Whale Detector". NOAA, National Marine Fisheries Service, Southwest Fisheries Science Center, Protected Resource Division. 2015. Archived from the original on 2016-02-23. Retrieved 2016-01-17.
  70. ^ "Western Pacific Gray Whale, Sakhalin Island 2010". Oregon State University, Marine Mammal Institute. February 2011. Retrieved 2011-02-25.
  71. ^ Rugh, David J.; Fraker, Mark A. (June 1981). "Gray Whale (Eschrichtius robustus) Sightings in Eastern Beaufort Sea" (PDF). Arctic. 34 (2). doi:10.14430/arctic2521. Retrieved 2010-07-15.
  72. ^ Shpak V.O.; Kuznetsova M.D.; Rozhnov V.V. (2013). "Observation of the Gray Whale (Eschrichtius robustus) in the Laptev Sea". Biology Bulletin. 40 (9): 797–800. doi:10.1134/S1062359013090100. S2CID 18169458.
  73. ^ Nefedova T., Gavrilo M., Gorshkov S. (2013). Летом в Арктике стало меньше льда Archived 2014-05-24 at the Wayback Machine. Russian Geographical Society. retrieved on 24-05-2014
  74. ^ Elwen H.S., Gridley T. (2013). Gray whale (Eschrichtius robustus) sighting in Namibia (SE Atlantic) – first record for Southern Hemisphere. Mammal Research Institute, the University of Pretoria and the Namibian Dolphin Project. retrieved on 18-05-2014
  75. ^ צפריר רינת 08.05.2010 16:47 עודכן ב: 16:50. "לווייתן אפור נצפה בפעם הראשונה מול חופי ישראל – מדע וסביבה – הארץ". Haaretz.co.il. Archived from the original on 2010-05-11. Retrieved 2012-06-26.
  76. ^ "Satellites witness lowest Arctic ice coverage in history". European Space Agency. Retrieved 2007-09-14.
  77. ^ Walker, Matt (30 May 2010). "Mystery gray whale sighted again off Spain coast". BBC News. Retrieved 8 June 2010.
  78. ^ Namibian Dolphin Project: A rare and mysterious visitor in Walvis Bay. Namibiandolphinproject.blogspot.ch (2013-05-14). Retrieved on 2013-07-28.
  79. ^ a b Alter, S. Elizabeth; Meyer, Matthias; Post, Klaas; Czechowski, Paul; Gravlund, Peter; Gaines, Cork; Rosenbaum, Howard C.; Kaschner, Kristin; Turvey, Samuel T.; Van Der Plicht, Johannes; Shapiro, Beth; Hofreiter, Michael (2015). "Climate impacts on transocean dispersal and habitat in gray whales from the Pleistocene to 2100". Molecular Ecology. 24 (7): 1510–1522. doi:10.1111/mec.13121. PMID 25753251. S2CID 17313811.
  80. ^ a b c d Rice, D.; Wolman, A. & Braham, H. (1984). "The Gray Whale, Eschrichtius robustus" (PDF). Marine Fisheries Review. 46 (4): 7–14.
  81. ^ a b c Jones, Mary Lou. "The Reproductive Cycle in Gray Whales Based on Photographic Resightings of Females on the Breeding Grounds from 1977–82" (PDF). Rep. Int. Whal. Comm. (t2): 177. Archived from the original (PDF) on 2012-04-26.
  82. ^ a b c Swartz, Steven L.; Taylor, Barbara L.; Rugh, David J. (2006). "Gray whale Eschrichtius robustus population and stock identity" (PDF). Mammal Review. 36 (1): 66–84. doi:10.1111/j.1365-2907.2006.00082.x. Archived from the original (PDF) on 2012-04-26.
  83. ^ The Marine Mammal Center. (n.d.). Retrieved February 21, 2020, from https://www.marinemammalcenter.org/education/marine-mammal-information/cetaceans/gray-whale.html Archived 2020-02-21 at the Wayback Machine
  84. ^ Solutions, Gray Whale Foundation | Rosodigital Creative. "The Gray Whale Foundation". www.graywhalefoundation.org. Archived from the original on 2018-02-03. Retrieved 2018-02-02.
  85. ^ "Conjoined gray whale calves discovered in Mexican lagoon could be". The Independent. January 8, 2014.
  86. ^ Oliver, J. S., Slattery, P. N., Silberstein , M. A., & O'Connor, E. F. (1981). A Comparison of Gray Whale, Eschrichtius robustus, Feeding in the Bering Sea and Baja California . Fishery Bulletin , 81(3), 513–522.
  87. ^ Newell, Carrie L.; Cowles, Timothy J. (30 November 2006). "Unusual gray whale Eschrichtius robustus feeding in the summer of 2005 off the central Oregon Coast". Geophysical Research Letters. 33 (22): L22S11. Bibcode:2006GeoRL..3322S11N. doi:10.1029/2006GL027189.
  88. ^ Dunham, J. S., & Duffus, D. A. (2001). Foraging patterns of gray whales in central Clayoquot Sound, British Columbia, Canada. Marine Ecology Progress Series , 223, 299–310.
  89. ^ Moore, Sue E.; Wynne, Kate M.; Kinney, Jaclyn Clement; Grebmeier, Jacqueline M. (April 2007). "Gray Whale Occurrence and Forage Southeast of Kodiak, Island, Alaska". Marine Mammal Science. 23 (2): 419–428. doi:10.1111/j.1748-7692.2007.00102.x.
  90. ^ "GRAY WHALE: ZoomWhales.com". Enchantedlearning.com. Retrieved 2012-06-26.
  91. ^ a b Weller, D.W.; Wursig, B.; Bradford, A.L.; Burdin, A.M.; Blokhin, S.A.; inakuchi, H. & Brownell, R.L. Jr. (1999). "Gray whales (Eschrichtius robustus) off Sakhalin Island, Russia: seasonal and annual patterns of occurrence". Mar. Mammal Sci. 15 (4): 1208–27. doi:10.1111/j.1748-7692.1999.tb00886.x.
  92. ^ Fadeev V.I. (2003). Benthos and prey studies in feeding grounds of the Okhotsk-Korean population of gray whales Archived 2017-01-06 at the Wayback Machine. Final report on materials from field studies on the research vessel Nevelskoy in 2002. Marine Biology Institute, Vladivostok.
  93. ^ a b Reeves, R.R., Brownell Jr., R.L., Burdin, A., Cooke, J.G., Darling, J.D., Donovan, G.P., Gulland, F.M.D., Moore, S.E., Nowacek, D.P., Ragen, T.J., Steiner, R.G., Van Blaricom, G.R., Vedenev, A. and Yablokov, A.V. (2005). Report of the Independent Scientific review Panel on the Impacts of Sakhalin II Phase 2 on Western Pacific Gray Whales and Related Biodiversity. IUCN, Gland Switzerland, and Cambridge, U.K.
  94. ^ a b Swartz, Steven L. (2018). "Gray Whale". Encyclopedia of Marine Mammals. pp. 422–428. doi:10.1016/B978-0-12-804327-1.00140-0. ISBN 9780128043271.
  95. ^ Pike, Gordon C. (1 May 1962). "Migration and Feeding of the Gray Whale (Eschrichtius gibbosus)". Journal of the Fisheries Research Board of Canada. 19 (5): 815–838. doi:10.1139/f62-051.
  96. ^ Map of the Gray Whale Migration. (n.d.). Retrieved from https://www.bajaecotours.com/gray-whale-migration-map.php
  97. ^ Davis, T.N. (1979-09-06). "Recovery of the Gray Whale". Alaska Science Forum. Archived from the original on 2009-02-12. Retrieved 2009-01-25.
  98. ^ Niemann, G. (2002). Baja Legends. Sunbelt Publications. pp. 171–173. ISBN 0-932653-47-2.
  99. ^ Findley, T.L.; Vidal, O. (2002). "Gray whale (Eschrichtius robustus) at calving sites in the Gulf of California, México". Journal of Cetacean Research and Management. 4 (1): 27–40.
  100. ^ Mark Carwardine, 2019, Bloomsbury Publishing, Handbook of Whales, Dolphins and Porpoises, p.80
  101. ^ Koontz, K. (n.d.). Close Encounters With Bajas Gray Whales. Retrieved February 21, 2020, from https://www.oceanicsociety.org/blog/1569/close-encounters-with-bajas-gray-whales Archived 2020-02-21 at the Wayback Machine
  102. ^ Lang, A. (January 19, 2011). "Demographic distinctness of the Pacific Coast Feeding Group of Gray Whales (Eschrictius robustus)". NOAA Fisheries Service, Protected Resource Division, Southwest Fisheries Science Center. Retrieved 2011-02-25.
  103. ^ a b c d "A Gray Area: On the Matter of Gray Whales in the Western North Pacific". 2015-05-07. Retrieved 2017-01-06.
  104. ^ a b c d e Nambu, Hisao; Ishikawa, Hajime & Yamada, Tadasu K. (2010). "Records of the western gray whale, Eschrichtius robustus: its distribution and migration" (PDF). Japan Cetology. 20 (20): 21–29. doi:10.5181/cetology.0.20_21. Archived from the original (PDF) on 2016-03-04. Retrieved 2015-10-15.
  105. ^ a b c "連鎖の崩壊 第3部 命のふるさと 2−四国新聞社". Retrieved 14 May 2015.
  106. ^ a b Suitube (2012). "中村宏治 コククジラ撮影秘話!". Japan Underwater Films. p. YouTube. Archived from the original on 2021-11-18. Retrieved 2015-01-07.
  107. ^ "コククジラが三河湾を回遊/絶滅恐れ、3月に1頭". 四国新聞社. Retrieved 14 May 2015.
  108. ^ "サービス終了のお知らせ". Archived from the original on 24 April 2014. Retrieved 14 May 2015.
  109. ^ a b "Nearly extinct western gray whale sighted again in coastal waters off Niigata". Asahi. 2015. Archived from the original on 2016-03-04.
  110. ^ a b Weller, D. W.; Takanawa, N.; Ohizumi, H.; Funahashi, N.; Sychenko, O. A.; Burdin, A. M.; Lang, A. R.; Brownell Jr., R. L. (2015). "Photographic match of a western gray whale between Sakhalin Island, Russia, and the Pacific Coast of Japan. Paper SC/66a/BRG/17". International Whaling Commission, Scientific Committee (SC66a meeting). San Diego, USA.
  111. ^ Vladimirov, V.L. (1994). "Recent distribution and abundance level of whales in Russian Far-Eastern seas". Russian J. Mar. Biol. 20: l–9.
  112. ^ Kato, H., Ishikawa, H., Bando, T., Mogoe, T. and Moronuki, H. (2006). Status Report of Conservation and Researches on the Western Gray Whales in Japan, June 2005 – May 2006. Paper SC/58/O14 presented to the IWC Scientific Committee, June 2006
  113. ^ Zhu, Q. (1998). "Strandings and sightings of the western Pacific stock of the gray whale Eschrichtius robustus in Chinese coastal waters. Paper SC/50lAS5 presented to the IWC Scientific Committee, April 1998, Oman
  114. ^ Краснокнижный серый кит приплыл под окна офиса заповедника «Командорский» Archived 2017-03-12 at the Wayback Machine. Retrieved on March 09, 2017
  115. ^ a b Nambu, Hisao; Minowa, Kazuhiro; Tokutake, Kouji & Yamada, Tadasu K. (2014). "New observations on Gray whales, Eschrichtius robustus, from Central Japan, Sea of Japan". Japan Cetology. 24 (24): 11–14. doi:10.5181/cetology.0.24_11.
  116. ^ Uni Y. (2004) 西部系群コククジラ Eschrictius robustus の記録集成と通過海峡 Archived 2015-09-24 at the Wayback Machine. dion.ne.jp
  117. ^ a b "珍客コククジラ 静岡沖で潮吹き". geocities.jp. Archived from the original on 2014-05-12. Retrieved 2014-05-09.
  118. ^ Brownell, R.L. Jr.; Chun, C. (1977). "Probable existence of the Korean stock of the gray whale (Eschrichtius robustus)". J. Mammal. 58 (2): 237–9. doi:10.2307/1379584. JSTOR 1379584.
  119. ^ Tsai, Cheng-Hsiu; Fordyce, R. Ewan; Chang, Chun-Hsiang; Lin, Liang-Kong (2014). "Quaternary Fossil Gray Whales from Taiwan". Paleontological Research. 18 (2): 82. doi:10.2517/2014PR009. S2CID 131250469.
  120. ^ Brownell, R.L., Donovan, G.P., Kato, H., Larsen, F., Mattila, D., Reeves, R.R., Rock, Y., Vladimirov, V., Weller, D. & Zhu, Q. (2010) Conservation Plan for Western North Pacific Gray Whales (Eschrichtius robustus). IUCN
  121. ^ 2014. Chuẩn hóa lại tên cá voi xám trong bộ sưu tập mẫu vật của bảo tàng lịch sử tỉnh Quảng Ninh Archived 2017-03-12 at the Wayback Machine. Retrieved on March 09, 2017
  122. ^ 2012. Bí ẩn những con cá khổng lồ dạt vào biển Việt Nam Archived 2017-03-12 at the Wayback Machine. Retrieved on March 09, 2017
  123. ^ a b What's on Xiamen.Tags> Pingtan gray whale Archived 2017-06-25 at the Wayback Machine. Retrieved on November 24. 2014
  124. ^ "濒危物种数据库 – 灰鲸 Eschrichtius robustus (Lilljeborg, 1861)". 中华人民共和国濒危物种科学委员会. p. the CITES. Archived from the original on 2014-12-25. Retrieved 2014-11-24.
  125. ^ Uni Y., 2010, 『コククジラは大隅海峡を通るのか?』, Japan Cetology Research Group News Letter 25, retrieved on 11-05-2014
  126. ^ "海棲哺乳類情報データベース". Archived from the original on 3 September 2015. Retrieved 14 May 2015.
  127. ^ Kim W.H., Sohn H.; An Y-R.; Park J.K.; Kim N.D.; Doo Hae An H.D. (2013). "Report of Gray Whale Sighting Survey off Korean waters from 2003 to 2011". Cetacean Research Institute, National Fisheries Research & Development Institute. Retrieved 2014-05-18. {{cite journal}}: Cite journal requires |journal= (help)
  128. ^ a b Disappearing Whales: Korea's Inconvenient Truth. Greenpeace (2012)
  129. ^ Hyun Woo Kim, Hawsun Sohn, Yasutaka Imai, 2018, Possible occurrence of a Gray Whale off Korea in 2015, International Whaling Commission, SC/67B/CMP/11 Rev1
  130. ^ Gagnon, Chuck (November 2016) Western gray whale activity in the East China Sea from acoustic data: Memorandum for Dr. Brandon Southall. iucn.org
  131. ^ Kato H.; Kishiro T.; Bando T.; Ohizumi H.; Nakamura G.; Okazoe N.; Yoshida H.; Mogoe T.; Miyashita T. (2015), "Status Report of Conservation and Researches on the Western North Pacific Gray Whales in Japan, May 2014 – April 2015", SC/66a/BRG, retrieved 2016-02-23
  132. ^ "Japan Underwater Films". Retrieved 14 May 2015.
  133. ^ a b Marine Mammals Stranding DataBase. kahaku.go.jp
  134. ^ "footage". Beachland.jp. Retrieved 2017-01-06.
  135. ^ 2012 年に漂着した海棲哺乳類につい. .beachland.jp
  136. ^ "伊勢湾でクジラ発見!!". Beachland.jp. Retrieved 2017-01-06.
  137. ^ ""プリン展"から"コククジラ展"へ". www.beachland.jp. Retrieved 2017-01-06.
  138. ^ Birdnetmaster (2015). "2014年 日本海に出現したコククジラ / Grey whale 2014 Sea of Japan". YouTube. Archived from the original on 2021-11-18. Retrieved 2015-10-14.
  139. ^ Aoyagi A.; Okuda J.; Nambu H.; Honma Y.; Yamada K. T.; Satou T.; Ohta M.; Ohara J.; Imamura M. (2014). "2014年春に新潟県信濃川大河津分水路河口付近に出現したコククジラの観察". Japan Cetology. 24: 15–22. doi:10.5181/cetology.0.24_15.
  140. ^ "寺泊沖にクジラ現る・長岡 「生きたまま初めて見た」地元驚き". The 47NEWS. Retrieved 14 May 2015.
  141. ^ Itou K. (2015). "絶滅危惧のコククジラ、2年連続で現れた 新潟・長岡". The Asahi Shimbun. Retrieved 2015-10-13.
  142. ^ Takanawa N. (2015). "【フォトギャラリー】伊豆諸島で見つかった希少なコククジラ". Japanese office of the National Geographic. Retrieved 2015-10-14.
  143. ^ "コククジラ in 日本(超貴重)Western Gray Whale sightings (Extremely Rare!)". YouTube. 2015. Retrieved 2015-10-14.
  144. ^ a b "ダイビング中にコククジラと遭遇のミラクル! ~房総半島・西川名と伊豆半島・赤沢で相次ぐ~ | オーシャナ". Oceana.ne.jp. 2016-01-19. Retrieved 2017-01-06.
  145. ^ "Ryo Okamoto – 伊良湖岬で釣りしてたら、クジラ出現。..." Facebook. 2015-03-23. Retrieved 2017-01-06.
  146. ^ "今日のコククジラ 館山 西川名 201601f". YouTube. 2016-01-09. Archived from the original on 2021-11-18. Retrieved 2017-01-06.
  147. ^ Braulik, Gill (2015-04-16) Young Gray Whale Sighted near Tokyo Islands. IUCN SSC – Cetacean Specialist Group
  148. ^ "赤沢 コククジラ 2016.1.14". YouTube. Archived from the original on 2021-11-18. Retrieved 2017-01-06.
  149. ^ "伊豆のダイビングサービス | ダイビングサービス mieux -みう- | クジラが~!!". Ds-mieux.com. Retrieved 2017-01-06.
  150. ^ "動画っす(`_´)ゞ – ダイビングサービス mieux – みう". Facebook. 2016-01-13. Retrieved 2017-01-06.
  151. ^ 絶滅心配 コククジラの死骸 千葉・南房総で見つかる. nhk.or.jp (2015-05-03)
  152. ^ "伊豆新聞デジタル – IZU SHIMBUN DIGITAL --". 伊豆新聞デジタル. Archived from the original on April 20, 2016.
  153. ^ 東京湾でクジラの目撃相次ぐ. Retrieved on April 21, 2017
  154. ^ 鎌倉ゴムボートコング山田肇. 2017.「https://www.youtube.com/watch?v=9v7b02cCsP0 ゴムボート東京湾ホエールウォッチング❗ 」. YouTube. Retrieved on April 21, 2017
  155. ^ みんなのニュース. 2017. 撮影成功! 姿現した「東京湾クジラ」 Archived 2017-04-22 at the Wayback Machine. The Fuji News Network Retrieved on April 22, 2017
  156. ^ "Gray Whales, Eschrichtius robustus". MarineBio.org. Archived from the original on 2018-12-15. Retrieved 2018-12-13.
  157. ^ a b c d e Henderson, David A. (1972). Men & Whales at Scammon's Lagoon. Los Angeles: Dawson's Book Shop.
  158. ^ Scammon, Charles Melville; David A. Henderson (1972). Journal aboard the bark Ocean Bird on a whaling voyage to Scammon's Lagoon, winter of 1858–59. Los Angeles: Dawson's Book Shop.
  159. ^ Tønnessen, Johan; Arne Odd Johnsen (1982). The History of Modern Whaling. University of California Press, Berkeley. ISBN 0-520-03973-4.
  160. ^ Brownell Jr., R. L. and Swartz, S. L. 2006. The floating factory ship California operations in Californian waters, 1932–1937. International Whaling Commission, Scientific Committee.
  161. ^ Kasuya, T. (2002). "Japanese whaling", in Encyclopedia of Marine Mammals. W. F. Perrin, B. Wursig, and J.G.M. Thewissen, eds. San Diego: Academic Press, pp. 655–662, ISBN 978-0-12-373553-9.
  162. ^ a b c David W. Weller; Alexander M. Burdin; Bernd Würsig; Barbara L. Taylor; Robert L. Brownell Jr; et al. (2002). "The western gray whale: a review of past exploitation, current status and potential threats". Journal of Cetacean Research and Management. 4 (1): 7–12 – via University of Nebraska - Lincoln.
  163. ^ Jón Guðmundsson lærði (1966). Ein stutt udirrietting um Íslands adskiljanlegu náttúrur. ed. Halldór Hermannsson, Cornell University Library, Ithaca, New York.
  164. ^ Russian Federation. (n.d.). Retrieved February 11, 2020, from https://iwc.int/russian-federation
  165. ^ Mapes, Lynda V.; Ervin, Keith (2007-09-09). "Gray whale shot, killed in rogue tribal hunt". The Seattle Times. Archived from the original on 2011-11-25.
  166. ^ "- 문화재검색결과 상세보기 – 문화재검색". Retrieved 14 May 2015.
  167. ^ "Gray Whale Migration Site (울산 귀신고래 회유해면)". Official Korea Tourism Organization.
  168. ^ Hooper, Rowan (23 July 2005). "Moving Whales Across the World". New Scientist. Retrieved 22 August 2013.
  169. ^ Hooper, Rowan (18 July 2005). "US whales may be brought to UK". BBC News. Retrieved 22 August 2013.
  170. ^ Monbiot, George (2013). Feral: Searching for Enchantment on the Frontiers of Rewilding. Allen Lane. ISBN 978-1-846-14748-7.
  171. ^ The Grey Whale (Eastern North Pacific Population) Archived January 14, 2016, at the Wayback Machine. Species at Risk. dfo-mpo.gc.ca
  172. ^ Yamada T.; Watanabe Y. "Marine Mammals Stranding DataBase – Gray Whale". The National Museum of Nature and Science. Archived from the original on 2014-05-12. Retrieved 2015-01-13.
  173. ^ Baker, C. S.; Dalebout, M. L.; Lento, G. M.; Funahashi, Naoko (2002). "Gray Whale Products Sold in Commercial Markets Along the Pacific Coast of Japan". Marine Mammal Science. 18: 295. doi:10.1111/j.1748-7692.2002.tb01036.x.
  174. ^ Noaa. (2020, January 17). 2019 Gray Whale Unusual Mortality Event along the West Coast. Retrieved February 11, 2020, from https://www.fisheries.noaa.gov/national/marine-life-distress/2019-gray-whale-unusual-mortality-event-along-west-coast
  175. ^ Daley, J. (2019, June 3). NOAA Is Investigating 70 Gray Whale Deaths Along the West Coast. Retrieved from https://www.smithsonianmag.com/smart-news/noaa-investigating-dozens-gray-whale-deaths-along-west-coast-180972333/
  176. ^ Solar Storms Might Be Causing Gray Whales to Get Lost. (n.d.). Retrieved February 11, 2020, from https://www.livescience.com/solar-storms-and-gray-whale-strandings.html
  177. ^ Vanselow, Klaus Heinrich; Jacobsen, Sven; Hall, Chris; Garthe, Stefan (15 August 2017). "Solar storms may trigger sperm whale strandings: explanation approaches for multiple strandings in the North Sea in 2016". International Journal of Astrobiology. 17 (4): 336–344. doi:10.1017/s147355041700026x.
  178. ^ "Deadly Killer Whale Moments (BBC Earth)".
  179. ^ Morell, V. (20 January 2011). "Killer Whales Earn Their Name". Science. 331 (6015): 274–276. Bibcode:2011Sci...331..274M. doi:10.1126/science.331.6015.274. PMID 21252323.
  180. ^ Hubbs, Carl L.; Evans, William E. (1974). "The California gray whale: papers presented at the California Gray Whale Workshop, Scripps Institution of Oceanography". Marine Fisheries Review. 36 (4).
  181. ^ Sumich, J. L.; Goff, T.; L. Perryman, W. (2001). "Growth of two captive gray whale calves" (PDF). Aquatic Mammals. 27 (3): 231–233.
  182. ^ Perry, Tony (1998). "Rescued Whale J.J. Begins Long Journey Home". LA Times. Retrieved 29 January 2016.
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Gray whale: Brief Summary

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The gray whale (Eschrichtius robustus), also known as the grey whale, gray back whale, Pacific gray whale, Korean gray whale, or California gray whale, is a baleen whale that migrates between feeding and breeding grounds yearly. It reaches a length of 14.9 meters (49 ft), a weight of up to 41 tonnes (90,000 lb) and lives between 55 and 70 years, although one female was estimated to be 75–80 years of age. The common name of the whale comes from the gray patches and white mottling on its dark skin. Gray whales were once called devil fish because of their fighting behavior when hunted. The gray whale is the sole living species in the genus Eschrichtius. It was formerly thought to be the sole living genus in the family Eschrichtiidae, but more recent evidence classifies members of that family in the family Balaenopteridae. This mammal is descended from filter-feeding whales that appeared during the Neogene.

The gray whale is distributed in an eastern North Pacific (North American), and an endangered western North Pacific (Asian), population. North Atlantic populations were extirpated (perhaps by whaling) on the European coast before AD 500, and on the American coast around the late 17th to early 18th centuries. However, in the 2010s there have been a number of sightings of gray whales in the Mediterranean Sea and even off Southern hemisphere Atlantic coasts.

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Baleine grise

provided by wikipedia FR

La Baleine grise (Eschrichtius robustus) est une espèce de cétacé, seule espèce du genre Eschrichtius et de la famille Eschrichtiidae. Elle a disparu de tout l'Océan Atlantique à la suite de la chasse baleinière mais une population existe encore dans le Pacifique[1].

Description

 src=
les évents forment un V.

La peau est souvent argentée, parsemée de taches blanchâtres et d'éraflures. Elle est souvent recouverte de balanes, bernacles et poux de baleines, notamment au niveau de la tête et de la queue[4].

La tête de la baleine grise est relativement petite comparée à celles des autres espèces. Elle ne fait qu'un sixième à un cinquième de la longueur totale de son corps. La largeur de sa tête est situé entre celle des baleines franches (Right whales en anglais) et des rorquals. Ses évents sont en V sur la partie reculée de sa tête. Très visibles sur le dessus de la tête, les deux narines qui forment l'évent se ferment hermétiquement lors des plongées[5].

Comme tous les mysticètes, la baleine grise est dépourvue de dents. Les fanons sont faits de kératine. Rangés en 160 paires de petits balais[6] (130 à 180), longs d'une soixantaine de centimètres, ils lui servent à filtrer les coquillages et les crustacés qu'elle trouve en aspirant la vase au fond de la mer. Les fanons auraient évolué à partir des plis transversaux qui rident la voûte du palais de la plupart des mammifères.

Sa nageoire caudale est son principal organe de natation : actionnée par une puissante musculature abdominale, elle la propulse à la manière d'une godille dont le va-et-vient ne serait pas latéral, mais horizontal. Ses nageoires latérales, assez réduites, ne servent qu'aux manœuvres d'équilibrage et d'orientation.

Reproduction

À l'époque des amours, plusieurs prétendants peuvent courtiser la même femelle en se roulant et se frottant sur elle. Après ces fiévreux ballets, l'accouplement proprement dit se pratique souvent à trois partenaires : les deux mâles qui s'efforcent de posséder la même femelle l'aident, en fait, alternativement, à maintenir son équilibre dans l'eau.

À sa naissance, un bébé baleine mesure de quatre mètre cinquante à cinq mètres et pèse cinq cents kilogrammes. En quelques mois, le baleineau double son poids.

Taxonomie

Le premier qui fit part d'une observation d'une baleine grise fut Paul Dudley en 1725. Dans le document retrouvé, il la nommait « scrag whale ». L'endroit où il l'avait observée se situait au large de la Nouvelle Angleterre (de la côte Est des États-Unis). En 1777, Erxlenben désigne cette baleine par le binôme « Balaena gibbosa », mais c'est le suédois Vilhelm Lilljeborg qui donne à l'espèce sa première description scientifique valide, sous le nom de Balaenoptera robusta en 1861. John Edward Gray déplace le taxon dans un genre à part entière, Eschrichtius, en 1864.

Répartition et habitat

 src=
Répartition contemporaine de la baleine grise.
  • Habitat : eaux côtières et eaux océaniques profondes.
  • Aire de répartition : région côtière du Pacifique nord.

Autrefois, cette espèce était commune dans l'Atlantique, mais elle en a été éradiquée par la pêche.

Population

La population est actuellement limitée au Pacifique. Les baleines se déplacent annuellement entre l'océan Arctique où elles se nourrissent de crustacés benthiques, situé entre la mer de Barents et la mer d'Okhotsk — entre l'Alaska et la Sibérie orientale — et des lieux de reproduction, situés autour du golfe de Californie et la mer de Chine orientale (mer de Corée).

 src=
Vertèbres

Une population aujourd'hui éteinte existait dans l'Atlantique. Elle a persisté jusqu'au XIXe siècle sur les côtes américaines et, peut-être, jusqu'au XVIIe dans les eaux européennes. Sa première description sur la côte Est des États-Unis est due à Paul Dudley, ancien gouverneur de la Nouvelle-Angleterre (1725) : « The Scrag Whale is near a-kin to the Fin-back, buts inftead of a Fin upon his Back, the Ridge of the Afterpart of his Back is scragged with half a Dozen Knobs or Nuckles ; he is nearest the right Whale in Figure and for Quantity of Oil ; his Bone is white but won't split ». Comme on le voit, cette « baleine rugueuse » n'est pas très clairement décrite. Elle fut ensuite ignorée par les grands zoologistes (Carl von Linné (1707-1778), Georges Cuvier (1769-1832), etc.) dont certains ne virent dans cette description qu'une baleine franche malade. Son existence scientifique a d'ailleurs d'abord été attestée à partir de restes de l'âge du fer trouvés sur une plage de l'île de Gräso, dans la mer Baltique[7]. Depuis, beaucoup de restes ont été trouvés, principalement aux Pays-Bas — lors des travaux de poldérisation entre 1879 et 1935, le plus récent étant daté du Ve siècle —, sur une plage en Grande-Bretagne en 1861 (Babbicombe Bay : ces restes, conservés au Natural History Museum de Londres, étaient vraisemblablement ceux des tout derniers individus ayant roulé depuis les fonds marins pendant deux siècles : ils ont été datés comme étant anciens de 340 ans[8]), ainsi que dans une carrière de Cornwall. Enfin, une série de restes ont été découverts en 1997 dans la cité antique de Lattara (Languedoc oriental, France) près de Montpellier[9]. Cette cité était le principal port de la zone et il est possible que les lagunes des côtes méditerranéennes (au moins occidentales en Espagne et France mais peut-être aussi au Maghreb et en Italie) aient hébergé des baleines grises lors de leurs séjours hivernaux comme lieu de reproduction.

Une étude génétique est en cours sur ces restes afin de caractériser cette population. Un projet de réintroduction dirigé par le Dr Owen Nevin de l'University of Central Lancashire à partir de la population est-pacifique est à l'étude depuis juillet 2005 (BBC News).

Par ailleurs, un spécimen a été observé en mai 2010 dans les eaux d'Israël [1]. L'individu selon toute vraisemblance a dû profiter de l'ouverture récurrente ces dernières années du passage du Nord-Ouest. Il a dû parcourir pour cela près de 20 000 km et la probabilité qu'il retrouve son chemin est assez mince en raison de la topographie en cul-de-sac latitudinal de la Méditerranée. Le même phénomène s'est répété au printemps 2021[10], un jeune animal étant observé en Méditerranée occidentale lors d'un passage très remarqué par les réseaux sociaux italiens et français[11].

Entre 2019 et 2020, plus de 300 baleines grises ont été retrouvées mortes sur la côté Pacifique. Si certains décès sont liés à des collisions, les scientifiques cherchent les causes associées à cette vague de mortalité (maladies, changements climatiques, migrations)[12].

Annexes

Références externes

Notes et références
  1. Bryant P.J (1995) Dating remains of gray whales from the eastern North Atlantic. Journal of Mammalogy, 76(3), 857-861. (résumé)
  2. Alain Diringer (préf. Marc Taquet), Mammifères marins et reptiles marins de l'océan Indien et du Pacifique, Éditions Orphie, 2020, 272 p. (ISBN 979-10-298-0254-6), Baleine grise pages 23-24
  3. (en) William Henry Burt, Richard Philip Grossenheider, A Field Guide to the Mammals, Houghton Mifflin, 1964, p. 242.
  4. Jean-Pierre Sylvestre, Cétacés du monde. Systématique, éthologie, biologie, écologie, statut, Quae, 2014, p. 38.
  5. Jean-Pierre Sylvestre, Cétacés du monde. Systématique, éthologie, biologie, écologie, statut, Quae, 2014, p. 37.
  6. (en) Robert Busch, Gray Whales : Wandering Giants, Heritage House Publishing Co, 1998, p. 44.
  7. (en) W. Lilljeborg, « On two subfossil whales discovered in Sweden », Nova Acta regiæ Societeit Scient. Upsaliensis, ser. III, vol. IV, no 3,‎ 1867, p. 1-48 (lire en ligne)
  8. (en) P. J. Bryant, « Dating Remains of Gray Whales from the Eastern North Atlantic », Journal of Mammalogy, vol. 76, no 3,‎ 1995, p. 857-861 (lire en ligne)
  9. (en) M. Macé, « Did the Gray Whale calve in the Mediterranean ? », Lattara, vol. 16,‎ 2003, p. 153-164 (lire en ligne)
  10. « Une baleine grise égarée observée pour la première fois en Méditerranée française », Le Point,‎ 2 mai 2021 (lire en ligne).
  11. « Du Maroc à Naples, Antibes et Bormes-les-Mimosas l'incroyable périple d'une jeune baleine grise perdue en Méditerranée », France TV Info,‎ 2 mai 2021 (lire en ligne).
  12. « Du Mexique à l’Alaska, une mystérieuse hécatombe chez les baleines grises », Le Monde,‎ 15 septembre 2020 (lire en ligne, consulté le 17 septembre 2020).

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Baleine grise: Brief Summary

provided by wikipedia FR

La Baleine grise (Eschrichtius robustus) est une espèce de cétacé, seule espèce du genre Eschrichtius et de la famille Eschrichtiidae. Elle a disparu de tout l'Océan Atlantique à la suite de la chasse baleinière mais une population existe encore dans le Pacifique.

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귀신고래

provided by wikipedia 한국어 위키백과

귀신고래(영어: gray whale / gray back whale, Pacific gray whale / California gray whale, 학명: Eschrichtius robustus)는 고래목 귀신고랫과에 속한 유일한 고래이다.[2] 쇠고래, 회색고래라고 부르기도 한다. 이 고래는 몸길이 15미터, 몸무게 36톤까지 자라며, 평균 수명은 50 ~ 60년이다. 현재는 북태평양에만 분포하며, 북아메리카 태평양 해안을 따라 이동하는 군(‘북동태평양 개체군’)과 동북아시아 연안을 따라 이동하는 군(‘북서태평양 개체군’)이 있지만, 이 두 개체군이 서로 아종으로 구분되지는 않는다. 즉, 이 두 개체군은 하나의 단일한 종으로 분류된다. 이동 거리는 혹등고래와 함께 고래 중에서 매우 긴 편에 속한다.[3]

한때는 두 군의 개체 수 모두 적었으나, 19세기부터 남획이 시작되어 개체수가 많이 줄어들었다. 북아메리카 연안을 따라 회유하는 북동태평양 개체군은 20세기에 들어 보호되기 시작해 현재는 2만 마리 이상으로 늘어났지만 동북아시아 연안을 회유하는 북서태평양 개체군의 경우, 과거에는 거의 한국과, 일본의 남획으로 인해, 한국이 포경산업을 공식적으로 포기한 현재는 일본의 남획으로 인해 개체수가 훨씬 적으며, 상태도 위태롭다. 대서양에도 귀신고래군이 있었으나, 17세기에 멸종되고 말았다.[4]

한편, 연오랑과 세오녀 설화에 나오는 움직이는 바위가 귀신고래의 등이라는 주장이 있다.[5]

분류

 src=
귀신고래와 다른 동물과의 관계를 나타내는 그림- 유전자 분석으로 나타난 결과

귀신고래는 현재 1과, 1속, 1종으로 분류되고 있지만, 최근 DNA 염기체 분석에 따르면 혹등고래대왕고래와 같은 수염고랫과의 종과 가깝게 나타난다.[3] 현재 북동태평양과 북서태평양에 두 가지의 개체군이 있지만, 유전적으로나 외관상으로 큰 차이가 없기 때문에 현재 아종으로 분류되지 않는다. 이들이 유전적으로 유사한 것에 대해서는 아직도 연구가 진행 중이다.

서방에서의 이 종에 대한 설명은 스웨덴잉글랜드에서 발견된 이들의 유골을 통해 진행되었다. 빌헬름 릴리에보리는 이들의 학명을 Balaenoptera robusta라고 지었으며,[6] 존 그레이가 1속 1종으로 분류하며 덴마크의 동물학자 다니엘 프레데리크 에스크리크트(Daniel Frederik Eschricht)를 기념하는 의미로 이명법 중 첫 부분을 Eschricht라고 바꾸었다.[7] 이명법(二名法)의 뒷부분인 robusta라틴어로 강함을 뜻한다.[3][8] 1869년에 코프(Cope)가 태평양에 분포하는 개체군을 Ranchianectes glaucus라고 설명하였다.[9] 대서양 개체군의 유골과 태평양 개체군과 비교한 결과 이 두 개체군은 같은 종으로 나타나 현재는 존 그레이가 붙인 이명법이 더 잘 쓰인다.[10][11] Eschrichtius gibbosus라는 이명법도 쓰이기도 한다.[12]

다음은 거테시 등(Gatesy et al..)의 계통 분류이다.[13]

고래하목 수염고래

Janjucetus

     

참고래과Megaptera novaeangliae NOAA.jpg

     

꼬마긴수염고래과

     

귀신고래과Eschrichtius robustus NOAA.jpg

   

수염고래과Megaptera novaeangliae NOAA.jpg

          이빨고래    

꼬마향고래과

   

향고래과Physeter macrocephalus NOAA.jpg

       

인도강돌고래과Lipotes vexillifer.png

     

부리고래과Ziphius cavirostris NOAA.jpg

       

아마존강돌고래과

   

라플라타돌고래과Pontoporia blainvillei.jpg

    참돌고래상과

참돌고래과Orcinus orca NOAA 2.jpg

     

쇠돌고래과

   

외뿔고래과Delphinapterus leucas NOAA.jpg

               

일반명

한국어로는 쇠고래라고도 한다. 얼럭덜럭한 몸을 지니며, 전체적으로는 회색빛을 띠기 때문에 영어권에서는 주로 회색고래(Gray Whale)라고 불리지만, 악마의 물고기(Devil Fish)라고 불리기도 하는데,[3] 예전에 포경업자에게 보였던 사나운 반응 때문이다.[3][14] 이는 19세기 중반에 미국의 포경업자들이 캘리포니아 이남에서 새끼를 기르는 개체를 자극함으로써 일어난 일로 여겨진다.[15] 일본의 포경업자가 그 뜻을 일본어로 그대로 옮겨,[15] 현재까지도 고쿠쿠지라(일본어: 極鯨(コククジラ) 코쿠쿠지라[*])라는 명칭이 일본에서는 쓰이고 있다. 일본 한자를 그대로 옮겨 ‘극경’(極鯨)이라고 불리기도 하며,[16] 귀신고래라는 이름은 해안에서 머리를 세우고 있다가 감쪽같이 사라진다고 해서 붙은 이름이다.[17]

외관과 행동 방식

 src=
해수면에서 엿보기를 하는 귀신고래

귀신고래는 겉으로 보기에 수염고래참고래의 중간 정도의 모습을 취하고 있다.[18] 위에서 보면 머리는 가늘며 삼각꼴이다.[3] 입의 모양은 약간 아치 모양으로 생겼으며, 양쪽에는 130에서 180개의 누런 빛의 고래수염판이 나 있다.[3]

귀신고래의 피부에는 긁힌 자국, 흩어져 붙어 있는 흰 따개비, 바다벼룩 등이 있으며, 기생체는 특히 머리 부분에 많이 나 있다. 하지만 우측에는 기생체가 거의 없는데,[19] 해저면에서 먹이를 뒤질 때 우측으로 기울기 때문이다. 갓 태어난 새끼는 회색에서 검은색이지만, 어떠한 개체는 구별되는 하얀 점 등을 지닐 수 있다.[19]

다른 수염고래와는 달리 귀신고래는 등지느러미가 없다. 하지만 몸의 뒷 부분에는 두드러지는 6에서 12개의 쐐기와 같은 것이 이어져 꼬리까지 나 있다. 가슴지느러미는 노처럼 생겼으며 끝은 뾰족하다. 꼬리의 길이는 가로로 3.7미터 정도이며, 중앙은 깊게 들어가 있다.[19]

다 자란 수컷의 몸길이는 13.7에서 14미터이며, 다 자란 암컷의 길이는 15m로 수컷보다 약간 크다. 성체의 몸무게는 27.2톤에서 36.3톤이다.[19]

귀신고래는 종종 머리를 드러내 수면 위를 엿보기를 한다. 머리의 윗부분에 있는 2개의 숨구멍을 이용해 공기를 들어 마신다. 쉴 때는 분당 2~3번씩 호흡을 하며, 깊게 잠수할 때는 3에서 5분 동안 숨을 마시기도 한다.[19] 이들이 뿜는 고래 분수의 높이는 3에서 4미터 정도이며, 소리는 1킬로미터 정도의 반경에서 들을 수 있다.[19] 분수에는 종종 냄새가 배어 있기도 하는데, 귀신고래가 질병에 걸렸을 때, 다쳤을 때, 먹고난 후 등에 냄새가 난다.[20]

생애

귀신고래는 5~11살이면 성적으로 성숙하며 이 때 몸길이는 11~12미터 정도이다.[21] 암컷은 2년 또는 3년에 한 번씩 출산한다.[3] 임신 기간은 12~13개월이고[3][21], 갓 태어난 새끼의 몸길이는 4.5미터이며, 몸무게는 500~680킬로그램 정도이다.[21] 보통 암컷은 한 마리씩만 출산하지만 드물게 2마리 이상 낳을 때도 있다.[19] 새끼는 다른 고래와는 달리 머리부터 태어나며 태어나자마자 본능적으로 수면 위로 올라가는데, 어미가 이것을 도와준다.[22] 젖은 지방질의 비중이 상당히 높아 농도가 인간은 2퍼센트에 불과한데 비해 귀신고래는 53퍼센트에 달한다.[19][21] 새끼는 보통 7~8개월이면 어미로부터 떨어진다.[3][21] 짝짓기 과정은 상당히 복잡하여 3마리 이상의 개체가 연루된다.[21] 암컷 한 마리를 두고 수컷 여러 마리가 경쟁하는 모습이 자주 보이는데, 이는 짝짓기에서 중요한 과정으로 여겨진다.[3] 짝짓기와 출산은 주로 회유지의 남한계에서 이루어지지만, 회유 도중에 일어난 경우도 있다.[21] 이들의 최고 수명은 75년으로 추정한다.[23]

먹이

다른 수염고래와는 아주 다르게, 이들은 주로 바닥에서 먹이를 먹는 데 특화되어 있으며,[18] 주식은 주로 해저면에 서식하는 무척추동물이다. 귀신고래의 고래수염은 30센티미터로 수염고래 중 가장 짧고, 목주름이 적어 팽창이 많이 되지 않기 때문에 이런 독특한 식습관에 의존할 수밖에 없다. 다른 수염고래같이 목을 팽창시킬 수 있으며, 많은 양의 먹이를 담아 걸러낼 수 있다. 양쪽 상반부 턱에 130에서 180개의 판이 있으며, 이 판은 손톱과 같은 케라틴질로 이루어져 있으며, 점차 고운 고래수염으로 자라난다.[21] 각 판의 길이는 5에서 25센티미터 정도이다.[21] 바다벼룩이나 잎새우같은 이각류를 주로 먹으며,[24] 얕은 해저면의 침전물을 뒤지면서 먹이를 걸러낸다.[3] 침전물을 뒤질 때는 몸을 옆으로 기울으며,[8] 주로 오른쪽으로 기우는 경향이 있다.[18] 귀신고래는 수면에 떠오른 뒤 수염을 통해 바닷물, 침전물 등을 걸러내며, 입에 남은 먹이를 통째로 삼킨다.[21] 미각이 있지만, 미신경이 작아 거의 못 느낀다고 여겨진다.[25]

이들이 해저면의 먹이 외에도 물에 떠다니는 작은 물고기 등을 먹는 것 또한 목격되었다.[3]

먹이가 이들의 주요 서식처를 결정하는 주요 요소이다. 5미터에서 24미터의 수심에서 먹이를 찾으며, 최소 3미터의 수심에서 발견된 적도 있다.[24] 이들이 먹이를 섭취하기 적합한 장소는 북쪽 지방이며, 두 가지 군 사이에 식성 차이는 없는 것으로 보인다.[24] 북쪽 지역에서 하루 동안 섭취량은 1,360에서 2,000킬로그램에 달한다.[26]

행동

 src=
고래뛰기 하는 귀신고래

고래 중에서는 이동 속도가 느린 편에 속한다. 헤엄치는 속도는 시속 6.4에서 8킬로미터 정도이며, 회유시 하루 최대 이동 거리는 100킬로미터 가까이 된다.[8] 개체 간의 유대감은 깊지 않으며, 보통 혼자 또는 작고 불완전한 무리를 이루어 이동한다.[3] 하지만 번식지와 거주지인 북방 한계에서 모두 수많은 개체가 군집하는 경우는 있다.[3] 다른 고래처럼 귀신고래도 고래뛰기를 하며, 외부 기생충이나 따개비를 떼어내려고 하거나 의사소통을 위해 사용되는 것으로 생각된다.

이들이 주로 해안가나 얕은 바다에 사는 이유는 이들이 오랫동안 잠수할 수가 없고,[27] 암초 사이에서 범고래와 같은 포식자들을 피하기 위해서라고 여겨진다.[28]

다 자란 귀신고래의 천적은 범고래인간뿐이다. 하지만 이들에게도 순순히 지지는 않는다. 포경업자들에게 보인 사나운 반응은 이들을 악마의 고기라 불리게 하였으며, 범고래에게도 반격을 가한다. 1966년 1월에 3마리의 귀신고래가 공격해오는 범고래에 저항하는 모습이 관찰된 바가 있는데, 귀신고래는 혼란에 빠지지 않고 꼬리로 쳐서 반격을 하였으며, 결국에 범고래들은 물러날 수밖에 없었다.[29] 물러난 원인으로는 귀신고래가 반격한 탓도 있지만, 현장을 관찰하던 배의 소음이 범고래의 의사소통을 방해하여 효과적인 사냥이 이루어질 수가 없었다.[29] 따라서 몸 군데군데에 범고래에게 물린 자국이 남아 있기도 한다.[30] 동태평양에서 관찰된 바로는 수심이 얕은 곳으로 도망가는 것으로 범고래의 협동공격을 피할 수도 있다.

노래

다른 많은 고래와 마찬가지로, 귀신고래 또한 노래를 이용한다. 노래라기보다는 꿀꿀거리는 소리에 가깝다.[31] 주로 번식지인 남한계에서 많이 이용되는 것으로 나타났으며, 북한계 지점에서는 그만큼 일어나지는 않는 것으로 나타났다.[32] 주파수는 1,500Hz 이하이며,[31] 아직까지 이들의 노래에 대해 자세히 조사된 적은 없다. 남한계에서는 번식에, 평상시에는 서로 간의 의사소통 중에 사용되며, 공기주머니를 쥐어짜서 소리를 내는 것으로 여겨진다.[33] 노래뿐만 아니라 고래뛰기를 함으로써 의사소통을 할 수도 있다.[19]

기생체

귀신고래에 기생하는 수많은 생물은 이들을 구분할 수 있는 척도가 된다. 이들의 피부에 기생하는 생물로는 따개비나 바닷니 등이며, 이들에만 사는 고유종 또한 있을 정도이다.[23][34] 따개비는 주로 귀신고래의 머리에 있으며, 반지름은 3.8센티미터 정도이다.[23] 바닷니는 주로 죽은 피부를 먹고 살지만, 생살을 먹기도 하며, 기생 부위는 숨구멍, 목주름, 눈, 귀, 생식기 등으로 다양하다.[23] 기생체의 무게를 합하면 무려 100킬로그램이나 된다.[23]

귀신고래는 기생체를 제거하기 위해 여러 가지 방법을 동원한다. 보통은 해저면이나 해안 가까이의 바위를 문질러 기생체를 떼어냄과 동시에 죽은 때를 밀어내기도 한다.[23] 심지어 어떤 경우는 민물에 접근하는 방법을 쓰기도 한다.[23]

분포와 이동

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북미의 귀신고래 무리를 그린 그림. 유빙에 고립된 무리를 표현하고 있다.

현재 귀신고래는 다른 대다수 고래류와는 달리 북태평양에서 2곳의 회유 경로를 따라 분포하며, 적도 이남에서 이들이 목격된 적은 없다.[3] 주로 먹이 등을 위해 얕은 바다의 해안가를 따라 서식하지만, 짝짓기와 번식을 위해서는 회유 경로의 최남단 지역으로 이동하며, 연간 회유거리는 2만 킬로미터를 넘는다. 회유 경로의 남한계는 두 개체군 모두 북회귀선에서 약간 낮은 지방이다. 이들이 회유 경로를 따라가는 방법을 설명하는 데는 여러 가설이 있는데, 지구자기장을 이용한다는 설, 태양을 이용한다는 설, 단순히 해안선을 따라 이동한다는 설, 해양 지형을 보고 이동한다는 설 등이 있다.[28] 임신한 암컷이 가을에 가장 먼저 이동하며, 그 뒤를 어른 수컷, 그리고 어린 무리가 따른다.[8] 이동 중에는 잠을 취하지 않는다고 여겨지며, 회유에 걸리는 기간은 2.5에서 3개월에 이른다.[8] 회유 중에는 먹이를 거의 먹지 않고,[35] 축적한 지방에 의존한다.

오호츠크 해동해를 오가는 작은 개체군은 북서태평양 개체군이라고 불리며 한국에서는 한국계 귀신고래라고도 불린다. 1912년 미국인 탐험가 로이 앤드류스가 ‘Korean stock of gray whales’ 라는 명칭을 붙였으나 현재는 학계에서 쓰지 않는 비공식 명칭이다. 앤드류스는 일본에서 한국의 동남해안에서 많이 잡히는 고래의 묘사가 그당시 멸종 위기에 놓여 잘 발견되지 않았던 동태평양 귀신고래와 비슷하다는 데에 착안해서 울산의 고래잡이 어장에서 2개월을 보내면서 귀신고래에 대해 연구하였다.[36] 여름에는 오호츠크 해 부근에서 보낸 후, 겨울에는 짝짓기와 출산을 위해 한국, 일본, 동중국해를 통해 남하하는 것으로 보인다. 추적과 현지 조사에 따르면 하이난의 얕은 바다에서 새끼를 낳는다.[37] 이 지역의 환경은 태평양 건너와 비슷하다.[37]

태평양 북동부에 있는 다른 개체군은 북동태평양 개체군 이라고 명칭되며 알래스카주, 캐나다 서안, 캘리포니아, 멕시코를 오간다. 이들은 작은 그룹으로 이동하며, 목적지는 멕시코바하칼리포르니아주캘리포니아만이다. 서태평양군처럼 회유 최남단 지역에서 짝짓기 및 번식을 한다. 바하칼리포르니아석호에서 새끼를 기르는데, 잔잔하고 얕은 물이 대형 상어나 범고래로부터 보호해 주기 때문으로 여겨진다.[35]

대서양에도 두 가지 개체군이 있었다고 추정되며, 한 가지의 군은 유럽 해안을 따라, 다른 개체군은 북미 연안을 따라 분포했으리라 여겨진다.[38] 하지만 이들의 회유 경로는 정확히 알려져 있지 않다.[38]

유전적으로 차이가 없다는 점과 북서태평양 개체군이 겨울에 어디로 가는지를 알 수 없다는 점을 들어 태평양의 두 개체군이 서로 섞일 수도 있다는 가능성도 제기되었다. 심지어 어떤 학자들은 현재 사할린에 있는 귀신고래들이 동태평양 개체에서 일시적으로 빠져나온 개체군이라고 설명한다.[39] 로이 앤드류스 또한 포경업자들을 조사한 결과 두 개체가 서로 북방 지역에서 만날 수도 있다고 추정했지만, 두 개체군 사이에서 번식은 일어나지 않을 것이라고도 하였다.[40] 하지만 이 가능성을 부정하는 의견은 귀신고래가 쉽게 길을 잃을 정도로 우매한 동물이 아니라는 점을 지적한다.[39] 또한 오호츠크 해쿠릴 제도캄차카 반도에 둘러싸이는 등 접근성이 떨어진다는 것 또한 언급한다.[39]

보존 상태와 전망

북태평양에 존재하는 개체군은 19세기에서 20세기까지는 포경업에 의해 개체 수가 직접적으로 영향을 받았다. 현재는 두 개체군 모두 포경 외의 요소에도 영향을 받고 있다. 북대서양의 개체군은 멸종되었으며, 이에 대해 잘 알려진 바는 없다. 20세기에 들어서 남획으로 개체 수가 줄어들었다가 효과적인 포경법이 개발된 후에는 다시 수난이 시작되었다.[35]

북서태평양

북서태평양에는 한때 많은 개체 수가 있었으나 오랜 기간 무분별하게 포획하여 그 수가 급감하였다. 한국의 귀신고래는 일제강점기 일본에 의해 남획되어 사라지게 되었다. 대한민국 정부는 1962년 울산 장생포 앞바다인 귀신고래 회유해면(廻遊海面)[42]을 천연기념물 126호로 지정하고 보호에 나섰으나, 1977년 이후로 대한민국에서는 발견되지 않고 있다.[43] 한때 북서태평양 귀신고래 개체군은 절멸했다고 여겨졌으나, 소련의 영향으로 인해 불가능했던[44] 북서태평양 개체군 귀신고래에 대한 조사가 시작되었고, 그 결과 사할린섬 연안에 생존해 있는 북서태평양 개체군 귀신고래 무리를 발견하였다. 현재 북서태평양 개체군 귀신고래는 약 130마리 정도가 남은 것으로 추정되며,[45] 연간 3퍼센트 수준으로 개체 수가 증가하고 있는 것으로 나타났다.[46]

이들이 북동태평양 개체군보다 훨씬 큰 수준의 위협에 놓인 이유로는 계속된 포획 때문이다. 한국에서는 천연기념물로 지정된 2년 뒤인 1964년까지도 포경이 이루어졌다는 기록이 있으며(1911년과 1964년 사이에 1338마리가 잡힌 기록이 있다.[46]), 일제 강점기에는 감소세에도 불구하고 남획이 계속되었다(북동태평양 개체군은 1940년대에 보호 조치가 내려졌다.). 현재는 이들이 서식하는 나라들이 이 종을 보호하기로 결의했지만, 현재는 포경 외의 요인에 위협을 받고 있다. 선박과 충돌하는 경우도 있으며, 현재 이들의 주요 서식지인 사할린 지역의 유전 개발은 그들의 서식지인 해저면을 변화시켜 생존에 영향을 끼칠 수가 있다. 유전은 이들의 먹이를 고갈시켜 생존에 영향을 미치고, 유전 발견을 위한 지질 조사는 이들을 자극함으로써 행동에 악영향을 끼칠 수 있다.[47] 북서태평양 개체군 귀신고래의 생존을 위해서는 사할린 지역의 무분별한 개발을 제한하고, 특히 암컷이 어망에 걸려 죽는 것을 막는 것이 중요한 것이다는 의견이 있다.[48][49]

북동태평양

북동태평양 개체군은 한때 남획으로 멸종 위기에 놓여 있어서 2천 마리 이하로 극감해 멸종했다고 여겨졌을 정도였다. 1937년에 미국에서 준보호 조치가 내려졌으며, 1947년부터 완전히 보호되기 시작한 이후 개체 수가 증가했다.[21] 이는 종족의 성공적인 회복의 전례로 종종 보고된다. 현재 개체 수는 26,635마리로 추산되며,[35] 남획 전 수치에 근접하는 것으로 보인다. 1994년 미국의 멸종 위기 종에서 해제되었으며,[50] 북방 회유지에서 원주민들이 이들을 정해진 만큼 포획이 허용되고 있다. 2003년에서 2007년까지 연당 최대 140마리를 잡도록 정해졌다.[51]

1999년에서 2000년 사이에 귀신고래가 좌초되어 죽는 개체 수가 해마다 수백 마리에 달한다고 조사되었다. 사망 요인으로 먹이 부족, 해양 오염, 전염병, 엘니뇨 등이 제기되고 있지만, 확실시 되는 것은 없다.[35] 개체 수가 증가해 이미 포화 상태에 도달했다는 의견도 있다.

이들도 한때 포경 이외의 활동에 위협을 받았다. 1994년 일본의 재벌인 미츠비시가 번식지인 바하칼리포르니아 근처에 소금 공장을 세우려는 계획을 내놓았으며, 멕시코 통상부가 이에 동조함에 따라 이 지역 및 전 세계적으로 이를 반대하는 움직임이 일어났다.[52] 결국에는 이 계획은 백지화되었지만,[52] 멕시코 정부는 이 지역에 관광업을 확대하려고 계획하고 있으며, 이는 귀신고래의 생존에 영향을 끼칠 수 있다.

대서양

대서양과 유럽에 있는 귀신고래군은 이미 14세기에 절멸되었으며,[23] 북미 연안에 있던 개체군은 18세기에 완전히 절멸당했다.[4] 멸종 원인으로는 남획이 제1순위로 꼽히는데, 반화석의 방사성 탄소 연대 측정법이 이 지역에 귀신고래군이 있었음을 증명한다.[53] 바스크인이 이르면 1372년부터 북미에서 귀신고래를 잡기 시작했다.[23] 17세기에서 18세기 동안에 이 지역에서 고래잡이가 증가했으며, 멸종 시기와도 맞아떨어진다.[53] 2005년 7월에는 센트럴랭크셔 대학의 과학자들이 동태평양의 개체들을 옮겨 아일랜드 해에 방사해 복원하려는 계획을 제안했지만, 그 계획이 실현될 수 있을지는 아직까지는 의문이다.[54]

인간과의 관계

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울산 대곡리 반구대 암각화 (복제품)

귀신고래는 오랜 옛날부터 서식지 인근의 문화의 표현 대상이 되어 왔다. 상업적 포경업이 금지된 현재에도 인간과 여러 면으로 떼어낼 수 없는 관계를 맺고 있다.

문화

귀신고래는 회유 인근 지역의 사람들에게 빠짐없이 묘사되었다.

축치인의 전설에는 다음과 같은 이야기가 전해온다.

먼 옛날에 바닷가에는 젊고 아름다운 처녀가 살았다. 처녀에 반한 고래가 바닷가에 접근하더니 잘생긴 청년으로 변했다. 결국에 그들은 바닷가에서 터전을 마련하며 함께 살았다. 처음 낳은 자식들은 고래였으며, 작을 때는 키워줬으나, 성장한 뒤에는 바다에 돌아갔다. 그 뒤에 낳은 자식은 모두 인간이었다. 아버지가 일을 못하게 되자, 자식들이 바다로 가서 식량을 구할 수밖에 없었다. 자식들이 바다로 가기 전에 아버지는 “바다는 너희 형제인 고래들의 고향이다. 잘 보호하도록 하여라.”라고 하였다. 자식들은 세월이 지나서 그 자신만의 가족을 형성하게 되었고, 아버지는 죽었다. 식량이 부족해지면서, 형제들은 왜 그렇게 많은 고래를 잡지 않았느냐고 불평을 하였다. 그래서 그들을 잡으러 나섰고, 고래는 아주 쉽게 잡혔다. 형제들은 잡은 고래를 어머니에게 보여주었지만, 어머니는 “너희는 단지 자신들과 닮지 않았다는 이유로 형제를 죽였다. 당장 내일은 무엇을 할 것이냐?”라는 말을 남기고는 죽었다. — Eyes of the Whale(고래의 눈)의 478~479쪽

밴쿠버섬 인근에 살던 원주민은 귀신고래를 토템, 상, 조각 등에서 수많이 표현했으며, 이는 현재까지도 지속되고 있다.[55]

한국에서는 울산 대곡리 반구대 암각화에서 귀신고래를 비롯한 여러 고래 등이 상세히 묘사되어 있으며, 이는 7천여 년 정도 된 것이다.[56] 한국의 유일한 태양신 신화인 연오랑과 세오녀에서 주인공 부부가 바위를 타서 일본에 건너 갔다고 하는데, 그 바위가 귀신고래였다는 설이 있을 정도로 예부터 동해안에 귀신고래가 많았다는 것을 말해준다.[17]

고래 관광

상당 부분 복구된 동태평양 개체군을 중심으로 이들의 회유지 경로인 브리티시 컬럼비아, 워싱턴주, 캘리포니아에 범고래 등을 묶어 함께 관찰하는 관광 사업이 많이 발달되어 있다. 회유 기간에는 고래 관광에 가장 적합한 고래 중의 하나로 꼽힌다. 과거에 포경업자에게 보인 사나운 태도와는 달리 관찰자에게는 호기심 깊게 접근하며, 심지어 머리를 쓰다듬게 놔두기도 한다. 이러한 귀신고래가 인간에게 보이는 친근감은 1970년대부터 높아지고 있으며, 관찰선에 몸을 비비는 것 또한 관찰되었다.[57] 이들을 관찰하기에 좋은 달은 1월에서 3월 사이에 남하할 때이며, 북상할 때는 해안에 거리를 두고 이동하기 때문에 최적기로 여겨지지 않는다.[58]

귀신고래를 비롯한 고래의 관찰은 관광객에게 즐거움을 줄 뿐만 아니라 지역 경제에 이바지하고 생물 교육의 좋은 현장으로 평가받고 있다.[57] 하지만 과도한 고래 관광업에 대한 우려도 제기되었는데, 이에 따라 선박은 고래와 인접시 엔진을 꺼야 하며, 최근에는 관찰 지역도 제한되고 있다.[57]

사육되는 귀신고래

귀신고래를 키우는 일은 쉽지 않으며, 지금까지 시도된 3건은 모두 씨월드가 주도한 것이다. 1965년에 부상당한 새끼를 잡아 기르려고 했지만, 2개월 만에 죽었다.[59] 이후에도 씨월드는 포기하지 않았고, 어미가 거세게 저항했지만 새끼를 어미로부터 떼어내는 데 성공했다.[59] 2개월 동안 먹지 않아 68킬로그램이나 체중이 줄었지만, 강제로 먹이는 것을 시작으로 먹이를 먹기 시작한 이후로 빠르게 성장하였다. 이름은 ‘Gigi’라고 명명되었으며, 체중을 재는 등 과학적으로 조사가 이루어졌다.[59] 조련사와 반려를 위한 돌고래에게 친근한 태도를 보여주었으며, 지나치게 성장하자 1972년 바다에 방사하기로 결정이 내려졌으며, 이때 몸길이는 8미터였으며 몸무게는 60톤이었다.[59] 세 번째 시도는 버려진 새끼를 1997년에 허락을 받아 잡아온 것이며, 1998년에 방사되었다. 이 개체의 성장률은 0.5킬로그램/시 로 상당히 빠른 편이었다.[59]

같이 보기

각주

  1. Reilly SB, Bannister JL, Best PB, Brown M, Brownell Jr. RL, Butterworth DS, Clapham PJ, Cooke J, Donovan GP, Urbán J & Zerbini AN (2008). “Eschrichtius robustus”. 《멸종 위기 종의 IUCN 적색 목록. 2012.2판》 (영어). 국제 자연 보전 연맹. 2013년 1월 18일에 확인함. CS1 관리 - 여러 이름 (링크)
  2. “귀신고래”. 울산 MBC. 2014년 5월 8일에 원본 문서에서 보존된 문서. 2008년 9월 12일에 확인함.
  3. Randall R.Reeves; Brent S.Stewart, Phillip J.Clapham, James A.Powell (2002). 《귀신고래》. 뉴욕시. 204-207쪽. 더 이상 지원되지 않는 변수를 사용함 (도움말); |확인날짜=|url=을 필요로 함 (도움말)
  4. Rice DW. 《Marine Mammals of the World. Systematics and Distribution. Special Publication Number 4.》 (영어). Lawrence, Kansas: The Society for Marine Mamalogy. 지원되지 않는 변수 무시됨: |출판= (도움말)
  5. 김장근 (2004년 11월 4일). “귀신고래는 돌아와야 한다”. 울산대학교 신문. 2014년 3월 27일에 원본 문서에서 보존된 문서. 2012년 1월 23일에 확인함.
  6. Lilljeborg (1861). “Balaenoptera robusta”. 《Forh. Skand. Naturf. Ottende Mode, Kopenhagen》 8: p.602. CS1 관리 - 추가 문구 (링크)
  7. 그레이(Gray) (1864). “Eschrichtius”. 《Ann. Mag. Nat. Hist.》 3 (14): p.350. CS1 관리 - 추가 문구 (링크)
  8. Adrian Forsyth (1999). 《Gray Whale(귀신고래)》. 버팔로, 뉴욕주. pp.260-263쪽. CS1 관리 - 추가 문구 (링크)
  9. Cope (1869). “Rhachianectes”. 《Proc. Acad. Nat. Sci. Philadelphia》 21: p.15. CS1 관리 - 추가 문구 (링크)
  10. Cederlund, BA (1938). “A subfossil gray whale discovered in Sweden in 1859”. 《Zoologiska Bidrag Fran Uppsala》 18: pp.269-286. CS1 관리 - 추가 문구 (링크)
  11. Mead JG, Mitchell ED (1984). 〈Atlantic gray whales〉. Jones ML, Swartz SL, Leatherwood S. 《귀신고래(The Gray Whale)》 (영어). 런던: Academic Press. pp.33-53쪽. CS1 관리 - 여러 이름 (링크) CS1 관리 - 추가 문구 (링크)
  12. Erxleben (1777). “Balaena gibbosa”. 《Systema regni animalis》: p.610. CS1 관리 - 추가 문구 (링크)
  13. John Gatesy, Jonathan H. Geisler, Joseph Chang, Carl Buell, Annalisa Berta, Robert W. Meredith, Mark S. Springer, Michael R. McGowen: A phylogenetic blueprint for a modern whale. In: Molecular Phylogenetics and Evolution. Volume 66, Issue 2, Februar 2013, S. 479–506. doi:10.1016/j.ympev.2012.10.012
  14. “ITIS (Eschrichtius robustus)”. 2008년 6월 26일에 확인함.
  15. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.20쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  16. 천연기념물 126호로 지정될 당시에 ‘귀신고래 회유해면’이 아닌 ‘극경 회유해면’이라는 이름이 붙었다. 문화재청은 울산시의 요청을 받아들여 ‘귀신고래 회유해면’으로 명칭 개정을 공고하였다. [1]
  17. 정성희 (2008년 1월 10일). “[횡설수설/정성희]귀신고래”. 동아일보. 2008년 7월 21일에 확인함.
  18. Mark Simmon (2004). Sue Viccars, 편집. 《Whales and Dolphins of the world》. 케임브리지, 매사추세츠: MIT 출판. pp.55-57쪽. 0-262-19519-4. |확인날짜=|url=을 필요로 함 (도움말) CS1 관리 - 추가 문구 (링크)
  19. “GRAY WHALE Eschrichtius robustus”. EnchantedLearning.com. 2008년 7월 22일에 확인함.
  20. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. pp.36-38쪽. 1-55143-114-9. CS1 관리 - 추가 문구 (링크)
  21. “귀신고래 (Eschrichtius robustus)”. American Cetacean Society. 2010년 6월 13일에 원본 문서에서 보존된 문서. 2008년 7월 23일에 확인함.
  22. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. pp.17-22쪽. 1-55143-114-9. CS1 관리 - 추가 문구 (링크)
  23. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. pp.56-65쪽. 1-55143-114-9. CS1 관리 - 추가 문구 (링크)
  24. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.442쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  25. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. pp.34-35쪽. 1-55143-114-9. CS1 관리 - 추가 문구 (링크)
  26. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. pp.44-49쪽. 1-55143-114-9. CS1 관리 - 추가 문구 (링크)
  27. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.464쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  28. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.239쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  29. “Three gray whales fight off killers in ocean battle (3마리의 귀신고래가 바다의 싸움에서 범고래를 물리치다”. San Diego Union. 1996. |확인날짜=|url=을 필요로 함 (도움말)
  30. Kathy Frost (1994). “Gray Whale”. Alaska Department of Fish and Game. 2008년 7월 23일에 확인함.
  31. “Gray whale vocalization”. 2008년 7월 23일에 확인함.
  32. Ollervides, Francisco (2002). “Past and present research on gray whale vocalizations”. 《Acoustical Society of America Journal》 (American Institute of Physics). 2008년 6월 23일에 확인함.
  33. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.456쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  34. 학명 Cryptolepas rhachignecti인 따개비가 있다.
  35. Doreen Moser; Frances Gulland. “Gray Whales-Current Status and Strandings (귀신고래 - 현황)” (PDF). San Francisco Bay National Refuge Complex. 2006년 10월 12일에 원본 문서 (PDF)에서 보존된 문서. 2008년 7월 27일에 확인함. 더 이상 지원되지 않는 변수를 사용함 (도움말)
  36. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.437쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  37. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.450쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  38. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. p.82쪽. 1-55143-114-9. CS1 관리 - 추가 문구 (링크)
  39. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. pp.447-449쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  40. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. pp.438-439쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  41. “울산 귀신고래 회유해면으로 불러주세요”. SBS. 2008년 9월 25일. 2008년 10월 4일에 확인함.
  42. 지정당시에는 울산 극경 회유해면이었다
  43. 김한태 (2005년 1월 4일). “돌아오지않는 귀신고래”. 경향신문. 2008년 7월 21일에 확인함.
  44. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.430쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  45. “북서태평양에 한국계 귀신고래 130마리 생존”. 연합뉴스. 2008년 10월 2일.
  46. “한국계 귀신고래 연 3% 증가”. 대한민국 해양수산부. 2006년 10월 9일. 2008년 7월 23일에 확인함.
  47. Dick Russel (2001). 《Eye of the Whale (고래의 눈)》. 뉴욕: Simon & Schuster. p.453쪽. 0-684-86608-0. CS1 관리 - 추가 문구 (링크)
  48. 비슷한 예로 암컷이 상대적으로 적은 북대서양참고래의 생존에도 매년 암컷 2마리가 죽는 것을 방지하는 것이 중요한 것이라는 의견이 있다. 자세한 내용은 참고래속#보전상태의 마지막 문장의 주를 참고
  49. 김태훈 (2008년 10월 6일). “귀신고래 몸엔 따개비와 이가 산다”. 세계일보. 2008년 10월 29일에 확인함.
  50. “ETWP; Final Rule to Remove the Eastern North Pacific Population of the Gray Whale From the List of Endangered Wildlife” (PDF). Department of the Interior- Fish and Wildlife Service. 1994년 6월 16일. 2008년 7월 27일에 확인함.
  51. “CATCH LIMITS FOR ABORIGINAL SUBSISTENCE WHALING”. 국제포경위원회. 2004. 2008년 7월 5일에 원본 문서에서 보존된 문서. 2008년 7월 27일에 확인함.
  52. Doug Thompson (2006). 《Whales-Touching the Mystery》. Oregon: NewSage Press. 0-939165-55-4.
  53. Bryant, PJ (1995년 8월). “Dating Remains of Gray Whales from the Eastern North Atlantic”. 《Journal of Mammalogy》 76 (3): pp.857~861. doi:10.2307/1382754. 더 이상 지원되지 않는 변수를 사용함 (도움말) CS1 관리 - 추가 문구 (링크)
  54. (BBC News)
  55. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. 1-55143-114-9.
  56. 이성원 (2008년 5월 24일). “길에서 띄우는 편지 7,000년을 고래와 함께한 울산”. 한국일보. 2014년 3월 27일에 원본 문서에서 보존된 문서. 2008년 7월 28일에 확인함.
  57. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. pp.104-108쪽. 1-55143-114-9. CS1 관리 - 추가 문구 (링크)
  58. “Gray Whale Migration: witness the annual winter journey...”. 2008년 7월 23일에 확인함.
  59. Robert H Bosch (1998). 《Gray whales- Wandering Giants》. Orca Book Publishers. pp.109-111쪽. 1-55143-114-9. CS1 관리 - 추가 문구 (링크)
license
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귀신고래: Brief Summary

provided by wikipedia 한국어 위키백과

귀신고래(영어: gray whale / gray back whale, Pacific gray whale / California gray whale, 학명: Eschrichtius robustus)는 고래목 귀신고랫과에 속한 유일한 고래이다. 쇠고래, 회색고래라고 부르기도 한다. 이 고래는 몸길이 15미터, 몸무게 36톤까지 자라며, 평균 수명은 50 ~ 60년이다. 현재는 북태평양에만 분포하며, 북아메리카 태평양 해안을 따라 이동하는 군(‘북동태평양 개체군’)과 동북아시아 연안을 따라 이동하는 군(‘북서태평양 개체군’)이 있지만, 이 두 개체군이 서로 아종으로 구분되지는 않는다. 즉, 이 두 개체군은 하나의 단일한 종으로 분류된다. 이동 거리는 혹등고래와 함께 고래 중에서 매우 긴 편에 속한다.

한때는 두 군의 개체 수 모두 적었으나, 19세기부터 남획이 시작되어 개체수가 많이 줄어들었다. 북아메리카 연안을 따라 회유하는 북동태평양 개체군은 20세기에 들어 보호되기 시작해 현재는 2만 마리 이상으로 늘어났지만 동북아시아 연안을 회유하는 북서태평양 개체군의 경우, 과거에는 거의 한국과, 일본의 남획으로 인해, 한국이 포경산업을 공식적으로 포기한 현재는 일본의 남획으로 인해 개체수가 훨씬 적으며, 상태도 위태롭다. 대서양에도 귀신고래군이 있었으나, 17세기에 멸종되고 말았다.

한편, 연오랑과 세오녀 설화에 나오는 움직이는 바위가 귀신고래의 등이라는 주장이 있다.

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Diet

provided by World Register of Marine Species
Bottom-dwelling amphipods, isopods, polychaete worms, mollusks, and other invertebrates and in some places at some times, various invertebrates at the surface or in the water column.The gammarid amphipod, Ampelisca macrocephala, is most likely the most commonly eaten prey in its main summer feeding grounds in the Bering Sea.
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copyright
WoRMS Editorial Board
bibliographic citation
van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO). IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS)
contributor
Kennedy, Mary [email]
contributor
Kennedy, Mary [email]

Distribution

provided by World Register of Marine Species
East Pacific, Indo-West Pacific
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copyright
WoRMS Editorial Board
bibliographic citation
van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO). IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS)
contributor
Kennedy, Mary [email]
contributor
Kennedy, Mary [email]

Habitat

provided by World Register of Marine Species
strongly coastal
license
cc-by-4.0
copyright
WoRMS Editorial Board
bibliographic citation
van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO). IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS)
contributor
Jacob van der Land [email]
contributor
Jacob van der Land [email]

Habitat

provided by World Register of Marine Species
often found within a kilometre of the coastal shore
license
cc-by-4.0
copyright
WoRMS Editorial Board
bibliographic citation
van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO). IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS)
contributor
Kennedy, Mary [email]
contributor
Kennedy, Mary [email]

IUCN Red List Category

provided by World Register of Marine Species
Least Concern (LC)
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copyright
WoRMS Editorial Board
bibliographic citation
van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO). IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS)
contributor
Perrin, William [email]
contributor
Perrin, William [email]

IUCN Red List Category

provided by World Register of Marine Species
subpopulation Northwest Pacific gray whale : Critically Endangered (CR)
license
cc-by-4.0
copyright
WoRMS Editorial Board
bibliographic citation
van der Land, J. (ed). (2008). UNESCO-IOC Register of Marine Organisms (URMO). IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. IUCN (2008) Cetacean update of the 2008 IUCN Red List of Threatened Species. North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS) North-West Atlantic Ocean species (NWARMS)
contributor
Perrin, William [email]
contributor
Perrin, William [email]