Sea Otter
A sea otter wraps itself in kelp in Morro Bay, California. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales Morro Bay is a waterfront city in San Luis Obispo County, California, United States.
Conservation status
Endangered (IUCN 2.3)
Scientific classification
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Order: Carnivora Family: Mustelidae Subfamily: Lutrinae Genus: Enhydra Fleming, 1828 Species: E. The conservation status of a Species is an indicator of the likelihood of that species remaining extant either in the present day or the near future An endangered species is a population of an organism which is at risk of becoming Extinct because it is either few in numbers or threatened by changing environmental or predation The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List) created in 1963 is the world's most comprehensive inventory of the global Chordates ( Phylum Chordata) are a group of Animals that includes the Vertebrates together with several closely related Invertebrates Vertebrates are members of the Subphylum Vertebrata, Chordates with backbones or spinal columns The grouping sometimes includes Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands The diverse order Carnivora (kɑrˈnɪvərə or sometimes /ˌkɑrnɪˈvɔərə/ from Latin carō (stem carn-) "flesh" + vorāre Mustelidae or Mustelids (from Latin mustela, Weasel) commonly referred to as the weasel family, is a family of carnivorous Mammals Otters are semi- aquatic (or in one case aquatic) fish-eating Mammals The otter subfamily Lutrinae forms part of the family John Fleming ( January 10, 1785 - November 18, 1857) was a Scottish Zoologist and Geologist. lutris
Binomial name
Enhydra lutris (Linnaeus, 1758)
Modern and historical range

The sea otter (Enhydra lutris) is a marine mammal native to the coasts of the northern and eastern North Pacific Ocean. Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as, May 23 new style (13 May old style 1707 who laid the foundations for Marine mammals are a diverse group of roughly 120 species of Mammal that are primarily Ocean -dwelling or depend on the ocean for food The Pacific Ocean is the largest of the Earth 's Oceanic divisions Adult sea otters typically weigh between 14 and 45 kg (30 to 100 lb), making them the heaviest members of the weasel family, but among the smallest marine mammals. The pound or pound-mass (abbreviation lb, lbm, or sometimes in the United States #) is a unit of Mass Mustelidae or Mustelids (from Latin mustela, Weasel) commonly referred to as the weasel family, is a family of carnivorous Mammals Unlike most marine mammals, the sea otter's primary form of insulation is an exceptionally thick coat of fur, the densest in the animal kingdom. Fur is a body hair of any non-human Mammal, also known as the Pelage. Although it can walk on land, the sea otter is capable of living exclusively in the ocean.

The sea otter inhabits nearshore environments where it can quickly dive to the sea floor to forage. It preys mostly upon marine invertebrates such as sea urchins, various mollusks and crustaceans, and some species of fish. Sea urchins are small globular spiny sea cat animals composing most of class Echinoidea. Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000 Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two Its foraging and eating habits are noteworthy in several respects. First, its use of rocks to dislodge prey and to open shells makes it one of the few mammal species to use tools. In most of its range, it is a keystone species, controlling sea urchin populations which would otherwise inflict extensive damage to kelp forest ecosystems. A keystone species is a Species that has a disproportionate effect on its environment relative to its abundance Kelp forests are underwater areas with a high density of Kelp. Finally, its diet includes prey species that are also valued by humans as food, leading to conflicts between sea otters and fisheries.

Sea otters, whose numbers were once estimated at 150,000–300,000, were hunted extensively for their fur between 1741 and 1911, and the world population fell to 1,000–2,000 individuals in a fraction of their historic range. A subsequent international ban on hunting, conservation efforts, and reintroduction programs into previously populated areas have contributed to numbers rebounding, and the species now occupies about two-thirds of its former range. The recovery of the sea otter is considered an important success in marine conservation, although populations in the Aleutian Islands and California have recently declined or have plateaued at depressed levels. Marine conservation, also known as marine resources conservation, is the protection and preservation of Ecosystems in Oceans and Seas Marine conservation The Aleutian Islands (possibly from Chukchi aliat, " Island " are a chain of more than 300 small volcanic islands forming a Volcanic California ( is a US state on the West Coast of the United States, along the Pacific Ocean. For these reasons (as well as its particular vulnerability to oil spills) the sea otter remains classified as an endangered species. For the fictional character see Oil Slick (Transformers. An oil spill is the release of a Liquid Petroleum Hydrocarbon into An endangered species is a population of an organism which is at risk of becoming Extinct because it is either few in numbers or threatened by changing environmental or predation

Taxonomy

The first scientific description of the sea otter is contained in the field notes of Georg Steller from 1751, and the species was described by Linnaeus in his Systema Naturae of 1758. Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as, May 23 new style (13 May old style 1707 who laid the foundations for The book Systema Naturae was one of the major works of the Swedish doctor of medicine Carolus Linnaeus. ^[1] Originally named Lutra marina, it underwent numerous name changes before being accepted as Enhydra lutris in 1922. ^[2] The generic name Enhydra, derives from the Ancient Greek en/εν "in" and hydra/ύδρα "water",^[3] meaning "in the water", and the Latin word lutris, meaning "otter". The Ancient Greek language is the historical stage in the development of the Hellenic language family spanning the Archaic (c Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. ^[4] It was formerly sometimes referred to as the "sea beaver",^[5] although it is only distantly related to beavers. Beavers are two primarily nocturnal semi-aquatic species of Rodent, one native to North America and one to Europe It is not to be confused with the marine otter, a rare otter species native to the southern west coast of South America. Marine Otters (Lontra felina are rare and poorly-known Marine mammals of the weasel family (Family Mustelidae) South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a A number of other otter species, while predominantly living in fresh water, are commonly found in marine coastal habitats as well.

Evolution

Although it is a relatively new marine mammal lineage, the sea otter can live in the ocean at all stages of life.

The sea otter is the heaviest member of the family Mustelidae,^[6][7] a diverse group that includes the thirteen otter species and terrestrial animals such as weasels, badgers, and minks. Mustelidae or Mustelids (from Latin mustela, Weasel) commonly referred to as the weasel family, is a family of carnivorous Mammals Otters are semi- aquatic (or in one case aquatic) fish-eating Mammals The otter subfamily Lutrinae forms part of the family Weasels are Mammals in the genus Mustela of the Mustelidae family. Badger is the Common name for any animal of three subfamilies which belong to the family Mustelidae: the same Mammal family as the There are two living species of " mink," the American Mink and the European Mink. It is unique among the mustelids in not making dens or burrows, in having no functional anal scent glands,^[8] and in being able to live its entire life without leaving the water. A lair is a underground or other enclosed place that Animals use to hide themselves while at Sleep, Hibernation or when they take part in Reproduction A burrow is a hole or tunnel dug into the ground by an Animal to create a space suitable for habitation temporary refuge or as a byproduct of locomotion The anal glands or anal sacs are small paired sacs located on either side of the anus between the external and internal sphincter muscles. ^[9] The only member of the genus Enhydra, the sea otter is so different from other mustelid species that as recently as 1982, some scientists believed it was more closely related to the earless seals. The true seals or earless seals are one of the three main groups of Mammals within the seal Suborder, Pinnipedia. ^[10] Genetic analysis indicates that the sea otter and its closest extant relatives, which include the African speckle-throated otter, Eurasian otter, African clawless otter and oriental small-clawed otter, shared an ancestor approximately 5 million years ago (mya). Extant is a term commonly used to refer to Taxa (such as Species, genera or families) that are still in existence (living The African Clawless Otter, Aonyx capensis, also known as the Cape Clawless Otter or Groot otter, is the second largest freshwater species of The Oriental Small-clawed Otter, Aonyx cinerea also known as Asian Small-clawed Otter is the smallest Otter in the world ^[11]

Fossil evidence indicates that the Enhydra lineage became isolated in the North Pacific approximately 2 mya, giving rise to the now-extinct Enhydra macrodonta and the modern sea otter, Enhydra lutris. ^[2] The sea otter evolved initially in northern Hokkaidō and Russia, then spread east to the Aleutian Islands, mainland Alaska, and down the North American coast. WikipediaWikiProject Japanese prefectures for guidelines --> formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan 's The Aleutian Islands (possibly from Chukchi aliat, " Island " are a chain of more than 300 small volcanic islands forming a Volcanic Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent ^[12] In comparison to cetaceans, sirenians, and pinnipeds, which entered the water approximately 50 mya, 40 mya, and 20 mya, respectively, the sea otter is a relative newcomer to a marine existence. The Order Cetacea (sɪˈteɪʃiə L cetus, whale includes Whales Dolphins and Porpoises Cetus is Not to be confused with order Sirenidae (aquatic salamanders For the Gothic metal band see Sirenia (band Sirenia Pinnipeds ("fin-feet" lit "winged feet" or fin-footed mammals are a widely distributed and diverse group of semi-aquatic marine Mammals comprising ^[13] In some respects, however, the sea otter is more fully aquatically adapted than pinnipeds, which must haul out on land or ice to give birth. ^[14]

Subspecies

There are three recognized subspecies, which vary in body size and in some skull and dental characteristics:^[6][15]

• The common sea otter, E. l. lutris (Linnaeus, 1758), ranges from the Kuril Islands to the Commander Islands in the western Pacific Ocean. The Kuril Islands (ˈkʊrɪl or /ˈkjuˈriˈl/ Кури́льские острова́ əstrʌˈva ru-Latn ''Kuril'skie ostrova'' or Kurile Islands in Russia Commander Islands or Komandorski Islands (Командо́рские острова́ Komandorskiye ostrova) are a group of treeless Russian Islands ^[6] Also known as the Asian sea otter, it is the largest subspecies with a wide skull and short nasal bones. ^[16]
• The southern sea otter, E. l. nereis (Merriam, 1904), is found off the coast of central California. California ( is a US state on the West Coast of the United States, along the Pacific Ocean. ^[6] Also known as the Californian sea otter, it has a narrower skull with a long rostrum and small teeth. A rostrum ( Latin for "beak" is an anatomical structure resembling a bird's beak, such as the snout of a Crocodile or Dolphin ^[16]
• The northern sea otter, E. l. kenyoni^[17] (Wilson, 1991), also known as the Alaskan sea otter, is native to the Aleutian Islands and mainland Alaska,^[16] but has since been re-introduced to various locations from Alaska to Oregon. Oregon ( is a state in the Pacific Northwest region of the United States. ^[6] While intermediate between the other subspecies in most characteristics, it has longer mandible bones. The mandible (from Latin mandibula, "jawbone" or inferior maxillary bone forms the lower Jaw and holds the lower teeth in place

Physical characteristics

A sea otter's thick fur makes its body appear much plumper on land than in the water.

The sea otter is one of the smallest marine mammal species. Marine mammals are a diverse group of roughly 120 species of Mammal that are primarily Ocean -dwelling or depend on the ocean for food ^[9] Male sea otters weigh 22 to 45 kg (49 to 99 lb) and are 1. 2 to 1. 5 m (4 to 5 ft) in length. M is the thirteenth letter of the modern Latin alphabet. Its name in English is spelled em (ɛm Females are smaller, weighing 14 to 33 kg (30 to 73 lb) and measuring 1. 0 to 1. 4 m (3 ft 3 in to 4 ft 7 in) in length. A foot (plural feet or foot; symbol or abbreviation ft or sometimes &prime – the prime symbol) is a non-SI unit Inches redirects here To see the Les Savy Fav album see Inches. ^[18]

Unlike other marine mammals, the sea otter has no blubber and relies on its exceptionally thick fur to keep warm. Blubber is a thick layer of vascularized Fat found under the skin of all Cetaceans Pinnipeds and Sirenians Description ^[19] With up to 150 thousand strands of hair per square centimeter (nearly one million per sq in), its fur is the most dense of any animal. Fur is a body hair of any non-human Mammal, also known as the Pelage. ^[20] The fur consists of long waterproof guard hairs and short underfur; the guard hairs keep the dense underfur layer dry. Cold water is thus kept completely away from the skin and heat loss is limited. ^[18] The fur is thick year-round, as it is shed and replaced gradually rather than in a distinct molting season. In Biology, moulting (or molting, also known as shedding or for some species Ecdysis) signifies the manner in which an animal routinely ^[21] As the ability of the guard hairs to repel water depends on utmost cleanliness, the sea otter has the ability to reach and groom the fur on any part of its body, taking advantage of its loose skin and an unusually supple skeleton. In Biology, the skeleton is a strong and often a rigid framework that supports the body of an animal holding it upright and giving it shape and strength (Also skeletal ^[22] The coloration of the pelage is usually deep brown with sliver-gray speckles, however it can range from yellowish or grayish brown to almost black. In Mammals pelage is the Hair, Fur, or Wool that covers the Animal. ^[23] In adults, the head, throat, and chest are lighter in color than the rest of the body. ^[23]

The sea otter displays numerous adaptations to its marine environment. The nostrils and small ears can close. ^[24] The hind feet, which provide most of its propulsion in swimming, are long, broadly flattened, and fully webbed. ^[25] The fifth digit on each hind foot is longest, facilitating swimming while on its back, but making walking difficult. ^[26] The tail is fairly short, thick, slightly flattened, and muscular. The front paws are short with retractable claws, with tough pads on the palms that enable gripping slippery prey. ^[27]

Skeleton of a sea otter. The hind flippers are larger than the mitten-like front paws.

The sea otter propels itself underwater by moving the rear end of its body, including its tail and hind feet, up and down,^[25] and is capable of speeds of up to 9 km/h (5. The kilometre ( American spelling: kilometer) symbol km is a unit of Length in the Metric system, equal to one thousand 6 mph). ^[6] When underwater, its body is long and streamlined, with the short forelimbs pressed closely against the chest. ^[28] When at the surface, it usually floats on its back and moves by sculling its feet and tail from side to side. ^[29] At rest, all four limbs can be folded onto the torso to conserve heat, whereas on particularly hot days the hind feet may be held underwater for cooling. ^[30] The sea otter's body is highly buoyant because of its large lung capacity – about 2. In Physics, buoyancy ( BrE IPA: /ˈbɔɪənsi/ is the upward Force on an object produced by the surrounding liquid or gas in which it is Lung volumes refers to physical differences in lung volume while lung capacities represent different combinations of lung volumes usually in relation to inhalation and exhalation 5 times greater than that of similarly-sized land mammals^[31] – and the air trapped in its fur. The sea otter walks with a clumsy rolling gait on land, and can run in a bounding motion. ^[26]

Long, highly sensitive whiskers and front paws help the sea otter find prey by touch when waters are dark or murky. ^[9] Researchers have noted that when they approach in plain view, sea otters react more rapidly when the wind is blowing towards the animals, indicating that the sense of smell is more important than sight as a warning sense. Olfaction (also known as olfactics or smell) refers to the Sense of smell. In Psychology, visual perception is the ability to interpret information from Visible light reaching the Eyes The resulting Perception is also ^[32] Other observations indicate that the sea otter's sense of sight is useful above and below the water, although not as good as that of seals. ^[33] Its hearing is neither particularly acute nor poor. ^[34]

An adult's 32 teeth, particularly the molars, are flattened and rounded, designed to crush rather than cut food. Molars are the rearmost and most complicated kind of Tooth in most Mammals In many mammals they grind food hence the Latin name mola, " Millstone ^[35] Seals and sea otters are the only carnivores with two pairs of lower incisor teeth rather than three;^[36] the adult dental formula is:^[37]

The sea otter has a metabolic rate two or three times that of comparatively sized terrestrial mammals. Basal metabolic rate ( BMR) is the amount of energy expended while at rest in a neutrally temperate environment in the post-absorptive state (meaning that the digestive system Terrestrial animals are Animals that live predominantly or entirely on land as compared with Aquatic animals which live predominantly or entirely in the water (e It must eat an estimated 25 to 38% of its own body weight in food each day in order to burn the calories necessary to counteract the loss of heat due to the cold water environment. ^[38][39] Its digestive efficiency is estimated at 80 to 85%,^[40] and food is digested and passed in as little as three hours. ^[19] Most of its need for water is met through food, although, in contrast to most other marine mammals, it also drinks seawater. Its relatively large kidneys enable it to derive fresh water from sea water and excrete concentrated urine. The kidneys are complicated organs that have numerous biological roles ^[41]

Behavior

Sensitive whiskers and forepaws enable sea otters to find prey using their sense of touch.

The sea otter is diurnal. In Animal behavior, diurnality indicates an Animal that is active during the Daytime and rests during the Night. It has a period of foraging and eating in the morning, starting about an hour before sunrise, then rests or sleeps in mid-day. ^[42] Foraging resumes for a few hours in the afternoon and subsides before sunset, and there may be a third foraging period around midnight. ^[42] Females with pups appear to be more inclined to feed at night. ^[42] Observations of the amount of time a sea otter must spend each day foraging range from 24 to 60%, apparently depending on the availability of food in the area. ^[43]

The sea otter spends much of its time grooming, which consists of cleaning the fur, untangling knots, removing loose fur, rubbing the fur to squeeze out water and introduce air, and blowing air into the fur. To an observer it appears as if the animal is scratching, however sea otters are not known to have lice or other parasites in the fur. Lice (singular louse) ( order Phthiraptera) are an order of over 3000 Species of wingless Insects three of which are classified ^[44] When eating, the sea otter rolls in the water frequently, apparently to wash food scraps from its fur. ^[45]

Foraging

The sea otter hunts in short dives, often to the sea floor. "Ocean Floor" redirects here For the 2001 song by Audio Adrenaline, see Lift (Audio Adrenaline album. Although it can hold its breath for up to five minutes,^[24] dives typically last about one minute and no more than four. ^[18] It is the only marine animal capable of lifting and turning over boulders, which it often does with its front paws when searching for prey. ^[45] The sea otter may also pluck snails and other organisms from kelp and dig deep into underwater mud for clams. The word snail is a Common name that can be used for almost all members of the Molluscan class Gastropoda which have coiled shells in the Clam is a word which can be used for all some or only a few Species of Bivalve Mollusks the word is a Common name which has ^[45] It is the only marine mammal that catches fish with its forepaws rather than with its teeth. Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two ^[19]

Under each foreleg, the sea otter has a loose pouch of skin that extends across the chest. In this pouch (preferentially the left one), the animal stores collected food to bring to the surface. ^[46] There, the sea otter eats while floating on its back, using its forepaws to tear food apart and bring it to its mouth. It can chew and swallow small mussels with their shells, whereas large mussel shells may be twisted apart. The common name mussel is used for members of several different families of Clams or Bivalve Molluscs, from both saltwater and freshwater habitats ^[47] It uses its lower incisor teeth to access the meat in shellfish. Incisors (from Latin incidere, "to cut" are the first kind of Tooth in Heterodont Mammals They are located in the Premaxilla ^[48] To eat large sea urchins, which are mostly covered with spines, the sea otter bites through the underside where the spines are shortest, and licks the soft contents out of the urchin's shell. ^[47]

The sea otter's use of rocks when hunting and feeding makes it one of the few mammal species to use tools. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands ^[49] To open hard shells, it may pound its prey with both paws against a rock on its chest. To pry an abalone off its rock, it hammers the abalone shell using a large stone, with observed rates of 45 blows in 15 seconds. Abalone (from Spanish Abulón) are medium-sized to very large edible sea Snails marine Gastropod Mollusks in the ^[18] Releasing an abalone, which can cling to rock with a force equal to 4,000 times its own body weight, requires multiple dives. ^[18]

To keep from drifting apart, sea otters may sleep holding paws. ^[50] Note the high buoyancy of the animals' bodies.

Social structure

Although each adult and independent juvenile forages alone, sea otters tend to rest together in single-sex groups called rafts. A raft typically contains 10 to 100 animals, with male rafts being larger than female ones. ^[51] The largest raft ever seen contained over 2000 sea otters. To keep from drifting out to sea when resting and eating, sea otters may wrap themselves in kelp. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales ^[52]

A male sea otter is most likely to mate if he maintains a breeding territory in an area that is also favored by females. ^[53] As autumn is the peak breeding season in most areas, males typically defend their territory only from spring to autumn. ^[53] During this time, males patrol the boundaries of their territories to exclude other males,^[53] although actual fighting is rare. ^[51] Adult females move freely between male territories, where they outnumber adult males by an average of five to one. ^[53] Males who do not have territories tend to congregate in large male-only groups,^[53] and swim through female areas when searching for a mate. ^[54]

The species exhibits a variety of vocal behaviors. The cry of a pup is often compared to that of a seagull. Gulls (often informally Seagulls) are birds in the family Laridae ^[55] Females coo when they are apparently content; males may grunt instead. ^[56] Distressed or frightened adults may whistle, hiss, or in extreme circumstances, scream. ^[55]

Although sea otters can be playful and sociable, they are not considered to be truly social animals. A social animal is a loosely defined term for an Organism that is highly interactive with other members of its Species to the point of having a recognizable ^[57] They spend much time alone, and each adult can meet its own needs in terms of hunting, grooming, and defense. ^[57]

Reproduction and lifecycle

During mating, the male bites the nose of the female, often bloodying and scarring it.

Sea otters are polygynous: males have multiple female partners. Polygyny (which comes from neo- Greek: πολύ poly "many" + γυνή gyny "woman" is a specific form of Polygamy, However, temporary pair-bonding occurs for a few days between a female in estrus and her mate. Oestrus is also the biological genus name of the gadfly. The estrous cycle (also oestrous cycle; derived from Latin ^[45] Mating takes place in the water and can be rough, the male biting the female on the muzzle – which often leaves scars on the nose – and sometimes holding her head under water. ^[6][58]

Births occur year-round, with peaks between May and June in northern populations and between January and March in southern populations. ^[59] Gestation appears to vary from four to twelve months, as the species is capable of delayed implantation followed by four months of pregnancy. Gestation is the carrying of an Embryo or Fetus inside a Female Viviparous Animal. Embryonic diapause or Delayed implantation is a reproductive strategy used by close to 100 different Mammals in seven different orders. ^[59] In California, sea otters usually breed every year, about twice as often as sea otters in Alaska. ^[60]

Birth usually takes place in the water and typically produces a single pup weighing 1. 4 to 2. 3 kg (3 to 5 lb). ^[61] Twins occur in 2% of births; however, usually only one pup survives. ^[6] At birth, the eyes are open, ten teeth are visible, and the pup has a thick coat of baby fur. ^[62] Mothers have been observed to lick and fluff a newborn for hours; after grooming, the pup's fur retains so much air that the pup floats like a cork and cannot dive. ^[63] The fluffy baby fur is replaced by adult fur after about thirteen weeks. ^[1]

A mother floats with her pup on her chest. Georg Steller wrote, "They embrace their young with an affection that is scarcely credible. "^[64]

Nursing lasts six to eight months in California populations and four to twelve months in Alaska, with the mother beginning to offer bits of prey at one to two months. Lactation describes the secretion of Milk from the Mammary glands the process of providing that milk to the young and the period of time that a Mother ^[65] The milk from a sea otter's two abdominal nipples is rich in fat and more similar to the milk of other marine mammals than to that of other mustelids. In its most general form a nipple is a Structure from which a fluid emanates Mustelidae or Mustelids (from Latin mustela, Weasel) commonly referred to as the weasel family, is a family of carnivorous Mammals ^[66] A pup, with guidance from its mother, practices swimming and diving for several weeks before it is able to reach the sea floor. Initially the objects it retrieves are of little food value, such as brightly colored starfish and pebbles. Starfish (also called sea stars) are any Echinoderms belonging to the class Asteroidea. ^[46] Juveniles are typically independent at six to eight months, however a mother may be forced to abandon a pup if she cannot find enough food for it^[67] and at the other extreme, a pup may nurse until it is almost adult size. ^[61] Pup mortality is high, particularly during an individual's first winter – by one estimate, only 25% of pups survive their first year. ^[67] Pups born to experienced mothers have the highest survival rates. ^[68]

Females perform all tasks of feeding and raising offspring, and have occasionally been observed caring for orphaned pups. ^[69] Much has been written about the level of devotion of sea otter mothers for their pups – a mother gives her infant almost constant attention, cradling it on her chest away from the cold water and attentively grooming its fur. ^[70] When foraging, she leaves her pup floating on the water, sometimes wrapped in kelp to keep it from floating away;^[71] if the pup is not sleeping, it cries loudly until she returns. ^[72] Mothers have been known to carry their pup for days after the pup's death. ^[64]

Females become sexually mature at around three or four years of age and males at around five; however, males often do not successfully breed until a few years later. ^[73] A captive male sired offspring at age 19. ^[61] In the wild, sea otters live to a maximum age of 23 years,^[18] with average lifespans of 10–15 years for males and 15–20 years for females. ^[74] Several captive individuals have lived past 20 years, and a female at the Seattle Aquarium died at the age of 28 years. The Seattle Aquarium is a public Aquarium located on Pier 59 on Seattle, USA 's Elliot Bay waterfront ^[75] Sea otters in the wild often develop worn teeth, which may account for their apparently shorter lifespans. ^[76]

Population and distribution

See also: Sea otter conservation

A raft of sea otters in Moss Landing, California. Modern efforts in sea otter conservation began in the early 20th century when the Sea otter was nearly extinct due to large-scale commercial hunting Moss Landing is a Census-designated place (CDP in Monterey County, California, United States.

Sea otters live in coastal waters 15 to 23 meters (50 to 75 ft) deep,^[77] and usually stay within a kilometer (⅔ mi) of the shore. ^[78] They are found most often in areas with protection from the most severe ocean winds, such as rocky coastlines, thick kelp forests, and barrier reefs. Kelp forests are underwater areas with a high density of Kelp. Coral reefs are Aragonite structures produced by living organisms found in marine waters with little to no nutrients in the water ^[79] Although they are most strongly associated with rocky substrates, sea otters can also live in areas where the sea floor consists primarily of mud, sand, or silt. Stream substrate ( Sediment) is the material that rests at the bottom of a Stream. ^[80] Their northern range is limited by ice, as sea otters can survive amidst drift ice but not land-fast ice. Drift ice is Sea ice that floats on the surface of the water in cold regions as opposed to Fast ice, which is attached ("fastened" to a shore Fast ice ( land-fast ice, landfast ice) is Sea ice that has frozen along Coasts ("fastened" to them along the Shoals or ^[81] Individuals generally occupy a home range a few kilometers long, and remain there year-round. ^[82]

The sea otter population is thought to have once been 150,000 to 300,000,^[5] stretching in an arc across the North Pacific from northern Japan to the central Baja Peninsula in Mexico. The Baja California peninsula ( English: Lower California peninsula) is a Peninsula in western Mexico. The fur trade that began in the 1740s reduced the sea otter's numbers to an estimated 1,000 to 2,000 members in thirteen colonies. In about two-thirds of its former range, the species is at varying levels of recovery, with high population densities in some areas and threatened populations in others. Threatened species are any species (including Animals Plants fungi, etc Sea otters currently have stable populations in parts of the Russian east coast, Alaska, British Columbia, Washington, and California, and there have been reports of recolonizations in Mexico and Japan. ^[83] Population estimates made between 2004 and 2007 give a worldwide total of approximately 107,000 sea otters. ^{[84][85][86][1][87]}

Russia

Currently, the most stable and secure part of the sea otter's range is Russia. Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending ^[88] Before the 19th century there were around 20,000 to 25,000 sea otters in the Kuril Islands, with more on Kamchatka and the Commander Islands. The Kuril Islands (ˈkʊrɪl or /ˈkjuˈriˈl/ Кури́льские острова́ əstrʌˈva ru-Latn ''Kuril'skie ostrova'' or Kurile Islands in Russia Commander Islands or Komandorski Islands (Командо́рские острова́ Komandorskiye ostrova) are a group of treeless Russian Islands After the years of the Great Hunt, the population in these areas, currently part of Russia, was only 750. ^[84] As of 2004, sea otters have repopulated all of their former habitat in these areas, with an estimated total population of about 27,000. Of these, about 19,000 are in the Kurils, 2000 to 3500 on Kamchatka and another 5000 to 5500 on the Commander Islands. ^[84] Growth has slowed slightly, suggesting that the numbers are reaching carrying capacity. The supportable Population of an Organism, given the food habitat, water and other necessities available within an environment is known as the environment's ^[84]

Alaska

Alaska is the heartland of the sea otter's range. Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent In 1973, the sea otter population in Alaska was estimated at between 100,000 and 125,000 animals. ^[89] By 2006, however, the Alaska population had fallen to an estimated 73,000 animals. ^[85] A massive decline in sea otter populations in the Aleutian Islands accounts for most of the change; the cause of this decline is not known, although orca predation is suspected. The Aleutian Islands (possibly from Chukchi aliat, " Island " are a chain of more than 300 small volcanic islands forming a Volcanic The Orca or Killer Whale ( Orcinus orca) less commonly Blackfish or Seawolf, is the largest species of the Oceanic dolphin family ^[90] The sea otter population in Prince William Sound was also hit hard by the Exxon Valdez oil spill, which killed thousands of sea otters in 1989. Prince William Sound is a sound of the Gulf of Alaska on the south coast of the U The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, on March 24 1989 ^[45]

British Columbia and Washington

Along the North American coast south of Alaska, the sea otter's range is discontinuous. Between 1969 and 1972, 89 sea otters were flown or shipped from Alaska to the west coast of Vancouver Island, British Columbia. Vancouver Island is a large Island in British Columbia, Canada, one of several North American regions named after George Vancouver, the British They established a healthy population, estimated to be over 3,000 as of 2004, and their range is now from Tofino to Cape Scott. Tofino is a Village of about 1650 residents on the west coast of Vancouver Island, in British Columbia Cape Scott Provincial Park is a Provincial park located at the northwestern tip of Vancouver Island, British Columbia, Canada. ^[86] In 1989, a separate colony was discovered in the central British Columbia coast. It is not known if this colony, which had a size of about 300 animals in 2004, was founded by transplanted otters or by survivors of the fur trade. ^[86]

In 1969 and 1970, 59 sea otters were translocated from Amchitka Island to Washington State. Annual surveys between 2000 and 2004 have recorded between 504 and 743 individuals, and their range is in the Olympic Peninsula from just south of Destruction Island to Pillar Point. Geography The Olympic Peninsula is home to some of the only Temperate rain forests in the world including the Hoh, Queets, and Quinault ^[1]

California has over 3,000 sea otters, descendants of approximately 50 individuals discovered in 1938.

In British Columbia and Washington, sea otters are found almost exclusively on the outer coasts. Reported sightings of sea otters in the San Juan Islands and Puget Sound almost always turn out to be northern river otters which are commonly seen along the seashore. The San Juan Islands are a part of the San Juan Archipelago in the northwest corner of the continental United States. Puget Sound (ˈpjuːʤᵻt is an arm of the Pacific Ocean, connected to the rest of the Pacific by the Strait of Juan de Fuca, in the Pacific Northwest However, biologists have confirmed isolated sightings of sea otters in these areas since the mid-1990s. ^[1]

California

The spring 2007 sea otter survey counted 3,026 sea otters in the central California coast, down from an estimated pre-fur trade population of 16,000. ^[87][91] California's sea otters are the descendants of a single colony of about 50 southern sea otters discovered near Big Sur in 1938;^[92] their principal range is now from just south of San Francisco to Santa Barbara County. Big Sur is a sparsely populated region of the central California, United States, coast where the Santa Lucia Mountains rise abruptly from the The City and County of San Francisco is the fourth most populous city Santa Barbara County is a County located on the Pacific coast of the southern portion of the U ^[91] In the late 1980s, the U.S. Fish and Wildlife Service relocated about 140 California sea otters to San Nicolas Island in southern California, in the hope of establishing a reserve population should the mainland be struck by an oil spill. San Nicolas Island is the most remote of California 's Channel Islands. To the surprise of biologists, the San Nicholas population initially shrank as the animals migrated back to the mainland,^[93] As of 2005, only 30 sea otters remained at San Nicholas,^[94] thriving on the abundant prey around the island. ^[93] The plan that authorized the translocation program had predicted that carrying capacity would be reached within 5 to 10 years.

When the Fish and Wildlife Service implemented the translocation program, it also attempted to implement "zonal management" of the California population. To manage the competition between sea otters and fisheries, it declared an "otter-free zone" stretching from Point Conception to the Mexican border. Point Conception extends into the Pacific Ocean in southwestern Santa Barbara County California. In this zone, only San Nicolas Island was designated as sea otter habitat, and sea otters found elsewhere in the area were supposed to be captured and relocated. These plans were abandoned after it proved impractical to capture the hundreds of otters which ignored regulations and swam into the zone. ^[95] However, after engaging in a period of public commentary in 2005, the Fish and Wildlife Service has yet to release a formal decision on the issue. ^[94]

Ecology

Diet

Sea otters keep kelp forests healthy by eating animals that graze on kelp. Kelp forests are underwater areas with a high density of Kelp.

Sea otters consume over 100 different prey species. ^[96] In most of its range, the sea otter's diet consists almost exclusively of marine invertebrates, including sea urchins, a variety of bivalves such as clams and mussels, abalone, other mollusks, crustaceans, and snails. Sea urchins are small globular spiny sea cat animals composing most of class Echinoidea. Bivalves are Molluscs belonging to the class Bivalvia. They have two-part shells and typically both valves are symmetrical along the hinge line Clam is a word which can be used for all some or only a few Species of Bivalve Mollusks the word is a Common name which has The common name mussel is used for members of several different families of Clams or Bivalve Molluscs, from both saltwater and freshwater habitats Abalone (from Spanish Abulón) are medium-sized to very large edible sea Snails marine Gastropod Mollusks in the Molluscs are animals belonging to the phylum Mollusca. There are around 250000 extant Species within the phylum with an estimated 70000 Structure of crustaceans As Arthropods crustaceans have a stiff Exoskeleton, which must be shed to allow the animal to grow ( Ecdysis or molting The word snail is a Common name that can be used for almost all members of the Molluscan class Gastropoda which have coiled shells in the ^[96] Its prey ranges in size from tiny limpets crabs and giant octopuses. The name Limpet is used for many kinds of mostly saltwater but also freshwater Snails specifically those that have a simple shell which is more or less broadly conical Crabs are decapod Crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (βραχύ / brachy Enteroctopus is an Octopus Genus, many of whose members are sometimes known as giant octopuses. ^[96] Where prey such as sea urchins, clams, and abalone are present in a range of sizes, sea otters tend to select larger items over smaller ones of similar type. ^[96] In California, it has been noted that sea otters ignore Pismo clams smaller than 3 inches (7 cm) across. ^[97]

In a few northern areas, fish are also eaten. In studies performed at Amchitka Island in the 1960s, where the sea otter population was at carrying capacity, 50% of food found in sea otter stomachs was fish. Amchitka (æmˈtʃɪtkə ( Amchixtax̂ in Aleut) is a volcanic tectonically unstable island in the Rat Islands group of the Aleutian Islands The supportable Population of an Organism, given the food habitat, water and other necessities available within an environment is known as the environment's ^[98] The fish species were usually bottom-dwelling and sedentary or sluggish forms, such as the red Irish lord and globefish. The red Irish lord, Hemilepidotus hemilepidotus, is a species of fish in the family Cottidae. Tetraodontidae is a family of primarily marine and estuarine fish ^[98] However, south of Alaska on the North American coast, fish are a negligible or extremely minor part of the sea otter's diet. ^[99][1] Contrary to popular depictions, sea otters rarely eat starfish, and any kelp that is consumed apparently passes through the sea otter's system undigested. Starfish (also called sea stars) are any Echinoderms belonging to the class Asteroidea. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales ^[100]

The individuals within a particular area often differ in their foraging methods and their prey types, and tend to follow the same patterns as their mothers. ^[101] The diet of local populations also changes over time, as sea otters can significantly deplete populations of highly preferred prey such as large sea urchins, and prey availability is also affected by other factors such as fishing by humans. ^[1] Sea otters can thoroughly remove abalone from an area except for specimens in deep rock crevices,^[102] however, they never completely wipe out a prey species from an area. ^[103] A 2007 California study demonstrated that in areas where food was relatively scarce, a wider variety of prey was consumed. However, surprisingly, the diets of individuals were more specialized in these areas than in areas where food was plentiful. ^[93]

As a keystone species

Sea otters are a classic example of a keystone species; their presence affects the ecosystem more profoundly than their size and numbers would suggest. A keystone species is a Species that has a disproportionate effect on its environment relative to its abundance Sea otters keep the population of certain benthic (sea floor) herbivores, particularly sea urchins, in check. The benthic zone is the ecological region at the lowest level of a Body of water such as an Ocean or a Lake, including the sediment surface and some sub-surface Sea urchins are small globular spiny sea cat animals composing most of class Echinoidea. Sea urchins graze on the lower stems of kelp, causing the kelp to drift away and die. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales Loss of the habitat and nutrients provided by kelp forests leads to profound cascade effects on the marine ecosystem. Kelp forests are underwater areas with a high density of Kelp. An ecological cascade effect is a series of secondary Extinctions that is triggered by the primary extinction of a key Species in an Ecosystem. North Pacific areas that do not have sea otters often turn into urchin barrens, with abundant sea urchins and no kelp forest. An urchin barren is an area of the subtidal where the population growth of Sea urchins has gone unchecked causing destructive grazing of kelp beds or kelp forests ^[6]

Remote areas of coastline, such as this area in California, sheltered the few remaining colonies of sea otters that survived the fur trade.

Reintroduction of sea otters to British Columbia has led to a dramatic improvement in the health of coastal ecosystems,^[104] and similar changes have been observed as sea otter populations recovered in the Aleutian and Commander Islands and the Big Sur coast of California^[105] However, some kelp forest ecosystems in California have also thrived without sea otters, with sea urchin populations apparently controlled by other factors. Big Sur is a sparsely populated region of the central California, United States, coast where the Santa Lucia Mountains rise abruptly from the An ecosystem is a natural unit consisting of all plants animals and micro-organisms( Biotic factors in an area functioning together with all of the non-living physical ( ^[105] The role of sea otters in maintaining kelp forests has been observed to be more important in areas of open coast than in more protected bays and estuaries. An estuary is a semi-enclosed Coastal body of Water with one or more Rivers or Streams flowing into it and with a free connection to the open ^[105]

In addition to promoting growth of kelp forests, sea otters can also have a profound effect in rocky areas that tend to be dominated by mussel beds. The common name mussel is used for members of several different families of Clams or Bivalve Molluscs, from both saltwater and freshwater habitats They remove mussels from rocks, liberating space for competitive species and thereby increasing the diversity of species in the area. ^[106]

Predators

Predators of sea otters include orcas and sea lions; bald eagles also prey on pups by snatching them from the water surface. The Orca or Killer Whale ( Orcinus orca) less commonly Blackfish or Seawolf, is the largest species of the Oceanic dolphin family For other uses of the term "sea lion" see Sea lion (disambiguation. The Bald Eagle ( Haliaeetus leucocephalus) is a Bird of prey found in North America that is most recognizable as the national bird and ^[49] In California, bites from sharks, particularly great white sharks, have been estimated to cause 10% of sea otter deaths and are one of the reasons the population has not expanded further north. Sharks ( Superorder Selachimorpha) are a type of Fish with a full cartilaginous Skeleton and a highly streamlined body The great white shark, Carcharodon carcharias, also known as white pointer, white shark, or white death, is an exceptionally large lamniform ^[107] Dead sea otters have been found with injuries from shark bites, although there is no evidence that sharks actually eat them. ^[107]

Relationship with humans

Fur trade

Aleut men in Unalaska in 1896. The Aleuts ( self-denomination from Aleut language allíthuh 'community' older or regional self-denomination Unangax̂, Unangan or Unalaska ( Nawan-Alaxsxa in Aleut) is an Island in the Fox Islands group of the Aleutian Islands in the U The waterproof kayak gear and garments were used to hunt sea otters. A kayak is a small human-powered Boat. It typically has a covered deck and a cockpit covered by a Spraydeck.

Archaeological evidence indicates that for thousands of years, indigenous peoples have hunted sea otters in moderation for food and fur. The term Indigenous Peoples or autochthonous peoples can be used to describe any Ethnic group who inhabit a geographic region with which they have the earliest historical ^[5] Large-scale hunting, which would eventually kill approximately one million sea otters, began in the 1700s when hunters and traders began to arrive from all over the world to meet foreign demand for otter pelts, which were one of the world's most valuable types of fur. ^[5]

In the early 1700s, Russians began to hunt sea otters in the Kuril Islands and sold them to China. The Kuril Islands (ˈkʊrɪl or /ˈkjuˈriˈl/ Кури́льские острова́ əstrʌˈva ru-Latn ''Kuril'skie ostrova'' or Kurile Islands in Russia China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National ^[5] Russia was also exploring the far northern Pacific at this time, and sent Vitus Bering to map the Arctic coast and find routes from Siberia to North America. Vitus Jonassen Bering (also less correctly Behring) ( August 1681 &ndash December 19, 1741) was a Danish -born navigator in the ^[108] In 1741, on his second North Pacific voyage, Bering was shipwrecked off Bering Island in the Commander Islands, where Bering and many of his crew died. Bering Island (о́стров Бе́ринга is located off the Kamchatka Peninsula in the Bering Sea. Commander Islands or Komandorski Islands (Командо́рские острова́ Komandorskiye ostrova) are a group of treeless Russian Islands ^[108] The surviving crew members, which included naturalist Georg Steller, discovered sea otters on the beaches of the island and spent the winter hunting sea otters and gambling with otter pelts. ^[108] They returned to Siberia having killed nearly 1000 sea otters, and were able to command high prices for the pelts. ^[108] Thus began what is sometimes called the "Great Hunt", which would continue for another hundred years.

Pelt sales (in thousands) in the London fur market. The drop beginning in the 1880s reflects dwindling sea otter populations. ^[109]

Russian fur-hunting expeditions soon depleted the sea otter populations in the Commander Islands, and by 1745 they began to move on to the Aleutian Islands. The Aleutian Islands (possibly from Chukchi aliat, " Island " are a chain of more than 300 small volcanic islands forming a Volcanic The Russians initially traded with the Aleuts inhabitants of these islands for otter pelts, but later enslaved the Aleuts, taking women and children hostage and torturing and killing Aleut men to force them to hunt. The Aleuts ( self-denomination from Aleut language allíthuh 'community' older or regional self-denomination Unangax̂, Unangan or Many Aleuts were either murdered by the Russians or died from diseases that the hunters had introduced. ^[110] The Aleut population was reduced, by the Russians' own estimate, from 20,000 to 2,000. ^[111] By the 1760s, the Russians had reached Alaska. Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent Other nations joined in the hunt in the south. Along the coasts of what is now Mexico and California, Spanish explorers bought sea otter pelts from Native Americans and sold them in Asia. The United Mexican States ( or commonly Mexico (ˈmɛksɪkoʊ () is a federal constitutional Republic in North America. California ( is a US state on the West Coast of the United States, along the Pacific Ocean. Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. For indigenous peoples in the United States other than Hawaii and Alaska see also Native Americans in the United States. ^[110] In 1778, British explorer Captain James Cook reached Vancouver Island and bought sea otter furs from the First Nations people. Captain James Cook FRS RN ( – 14 February 1779) was an English Explorer, Navigator and Vancouver Island is a large Island in British Columbia, Canada, one of several North American regions named after George Vancouver, the British ^[112] When Cook's ship later stopped at a Chinese port, the pelts rapidly sold at high prices, and were soon known as "soft gold". China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National As word spread, people from all over Europe and North America began to arrive in the Pacific Northwest to trade for sea otter furs. The Pacific Northwest is a region in the northwest of North America (the term refers to the land not the ocean ^[112]

Russian hunting expanded to the south, in what is now Washington, Oregon, and California, and the Russians founded what is now the Fort Ross settlement in northern California as their southern headquarters. ^[112] In the next 29 years, they would kill 50,000 California sea otters. ^[112]

Eventually, sea otter populations became so depleted that commercial hunting was no longer viable. In the Aleutian Islands, commercial hunting had stopped by 1808. ^[113] When Russia sold Alaska to the United States in 1867, the Alaska population had recovered to over 100,000, but Americans resumed hunting and quickly extirpated the sea otter again. The Alaska Purchase (otherwise known as Seward's Folly or Seward's Icebox) by the United States from the Russian Empire occurred in 1867 at the behest ^[113] Prices rose as the species became rare: During the 1880s, a pelt brought $105 to $165 in the London market, however by 1903 a pelt could be worth as much as $1,125. ^[61] In 1911, Russia, Japan, Great Britain (for Canada) and the United States signed the Treaty for the Preservation and Protection of Fur Seals, imposing a moratorium on the harvesting of sea otters. ^[114] So few remained, perhaps only 1,000–2,000 individuals in the wild, that many believed the species would become extinct. In Biology and Ecology, extinction is the cessation of existence of a Species or group of taxa. ^[1]

Recovery and conservation

Main article: Sea otter conservation

In the wake of the Exxon Valdez oil spill, heavy sheens of oil covered large areas of Prince William Sound. Modern efforts in sea otter conservation began in the early 20th century when the Sea otter was nearly extinct due to large-scale commercial hunting The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, on March 24 1989 Prince William Sound is a sound of the Gulf of Alaska on the south coast of the U

During the 20th century, sea otter numbers rebounded in about two-thirds of their historic range, a recovery that is considered one of the greatest successes in marine conservation. ^[115] However, the IUCN lists the sea otter as an endangered species, and describes the significant threats to sea otters as oil pollution, predation by orcas, poaching, and conflicts with fisheries – sea otters can drown if entangled in fishing gear. An endangered species is a population of an organism which is at risk of becoming Extinct because it is either few in numbers or threatened by changing environmental or predation For the fictional character see Oil Slick (Transformers. An oil spill is the release of a Liquid Petroleum Hydrocarbon into The Orca or Killer Whale ( Orcinus orca) less commonly Blackfish or Seawolf, is the largest species of the Oceanic dolphin family Poaching is the illegal Hunting, Fishing or Harvesting of wild plants or animals ^[116] The hunting of sea otters is no longer legal except for limited harvests by indigenous peoples in the United States. The term Indigenous Peoples or autochthonous peoples can be used to describe any Ethnic group who inhabit a geographic region with which they have the earliest historical ^[117] Poaching was a serious concern in the Russian Far East immediately after the collapse of the Soviet Union in 1991, however it has declined significantly with stricter law enforcement and better economic conditions. The Soviet Union 's collapse into independent nations began early in 1985 ^[88]

The most significant threat to sea otters is oil spills. For the fictional character see Oil Slick (Transformers. An oil spill is the release of a Liquid Petroleum Hydrocarbon into ^[49] Sea otters are particularly vulnerable, as they rely on their fur to keep warm. When their fur is soaked with oil, it loses its ability to retain air, and the animal quickly dies from hypothermia. Hypothermia is a condition in which an organism's temperature drops below that required for normal Metabolism and bodily functions ^[49] The liver, kidneys, and lungs of sea otters also become damaged after they inhale oil or ingest it when grooming. The liver is a vital organ in the human body and is present in Vertebrates and some other animals The kidneys are complicated organs that have numerous biological roles lung is the essential Respiration organ in air-breathing Animals including most Tetrapods a few Fish and a few Snails The most primitive ^[49] The Exxon Valdez oil spill of 24 March 1989 killed thousands of sea otters in Prince William Sound, and as of 2006 the lingering oil in the area continues to affect the population. The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, on March 24 1989 Prince William Sound is a sound of the Gulf of Alaska on the south coast of the U ^[118] Describing the public sympathy for sea otters that developed from media coverage of the event, a U. S. Fish and Wildlife Service spokesperson wrote:

As a playful, photogenic, innocent bystander, the sea otter epitomized the role of victim . . . cute and frolicsome sea otters suddenly in distress, oiled, frightened, and dying, in a losing battle with the oil. ^[1]

The small geographic ranges of the sea otter populations in California, Washington, and British Columbia mean that a single major spill could be catastrophic for that state or province. ^[45][39][1] Prevention of oil spills and preparation for the rescue of otters in the event of one are major areas of focus for conservation efforts. Increasing the size and the range of sea otter populations would also reduce the risk of an oil spill wiping out a population. ^[1] However, because of the species' reputation for depleting shellfish resources, advocates for commercial, recreational, and subsistence shellfish harvesting have often opposed allowing the sea otter's range to increase, and there have even been instances of fishermen and others illegally killing them. ^[119]

Sea otters in the Olympic Coast National Marine Sanctuary. The Olympic Coast National Marine Sanctuary is one of 14 marine sanctuaries in the U Note the unusual shape of the hind feet, in which the outer toes are longest.

In the Aleutian Islands, a massive and unexpected disappearance of sea otters has occurred in recent decades. In the 1980s, the area was home to an estimated 55,000 to 100,000 sea otters, but the population fell to around 6,000 animals by 2000. ^[95] The most widely-accepted, but still controversial, hypothesis is that orcas have been eating the otters. The Orca or Killer Whale ( Orcinus orca) less commonly Blackfish or Seawolf, is the largest species of the Oceanic dolphin family The pattern of sea otter disappearances is consistent with a rise in orca predation, however there has been no direct evidence that orcas prey on sea otters to any significant extent. ^[90]

Another area of concern is California, where recovery began to fluctuate or decline in the late 1990s. ^[120] Unusually high mortality rates amongst adult and sub-adult otters, particularly females, have been reported. ^[87] Necropsies of dead sea otters indicate that diseases, particularly Toxoplasma gondii infection and acanthocephalan parasite infection, are a major cause of sea otter mortality in California. An autopsy, also known as a post-mortem examination, necropsy, or obduction, is a Medical procedure that consists of a thorough Examination Toxoplasma gondii is a species of parasitic Protozoa in the Genus Toxoplasma. The Acanthocephala ( Greek ακανθος akanthos, thorn + κεφαλη kephale, head is a phylum of Parasitic worms known as ^[121] The Toxoplasma gondii parasite, which is often fatal to sea otters, is carried by wild and domestic cats and by opossums, and may be transmitted by domestic cat droppings flushed into the ocean via the sewage system. Didelphimorphia is the order of common opossums of the Western Hemisphere. ^[121][122] Although it is clear that disease has contributed to the deaths of many of California's sea otters, it is not known why the California population is apparently more affected by disease than populations in other areas. ^[121]

Sea otter habitat is preserved through several protected areas in the United States, Russia and Canada. Marine Protected Area (MPA is often used as an umbrella term covering a wide range of marine areas with some level of restriction to protect living non-living cultural and/or historic The Protected areas of the United States are managed by an array of different federal state tribal and local level authorities and receive widely varying levels The status of the protected areas in Russia (the official Russian term Особо охраняемые природные территории literally "Specially Protected Natural Protected areas of Canada have been created to protect Ecological integrity, as well as to provide areas for Recreation and Education. In marine protected areas, polluting activities such as dumping of waste and oil drilling are typically prohibited. ^[123] There are estimated to be more than 1,200 sea otters within the Monterey Bay National Marine Sanctuary, and more than 500 within the Olympic Coast National Marine Sanctuary. The Monterey Bay National Marine Sanctuary (MBNMS is a Federally protected marine area offshore of California 's central coast. The Olympic Coast National Marine Sanctuary is one of 14 marine sanctuaries in the U ^{[124] [125]}

Economic impact

A sea otter using a rock to break open a shell

Some of the sea otter's preferred prey species, particularly abalone, clams, and crabs, are also food sources for humans. Abalone (from Spanish Abulón) are medium-sized to very large edible sea Snails marine Gastropod Mollusks in the Clam is a word which can be used for all some or only a few Species of Bivalve Mollusks the word is a Common name which has Crabs are decapod Crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (βραχύ / brachy In some areas, massive declines in shellfish harvests have been blamed on the sea otter, and intense public debate has taken place over how to manage the competition between sea otters and humans for seafood. Shellfish is a Culinary and Fisheries term for those aquatic Invertebrate animals that are used as Food: various species of molluscs ^[126]

The debate is complicated by the fact that sea otters have sometimes been held responsible for declines of shellfish stocks that were more likely caused by overfishing by humans, disease, pollution, and seismic activity. Overfishing occurs when Fishing activities reduce fish stocks below an acceptable level Seismology (from Greek grc σεισμός seismos, "earthquake" and grc -λογία -logia) is the scientific study of Earthquakes ^[127][45] Shellfish declines have also occurred in many parts of the North American Pacific coast that do not have sea otters, and conservationists sometimes note that the existence of large concentrations of shellfish on the coast is a recent development resulting from the fur trade's near-extirpation of the sea otter. Local extinction is where a Species (or other Taxon) ceases to exist in the chosen area of study but still exists elsewhere ^[127] Although many factors affect shellfish stocks, sea otter predation can deplete a fishery to the point that it is no longer commercially viable. ^[126] There is a consensus among scientists that sea otters and abalone fisheries cannot co-exist in the same area,^[126] and the same is likely true for certain other types of shellfish as well. ^[95]

There are many facets to the interaction between sea otters and the human economy that are not as immediately felt. Sea otters have been credited with contributing to the kelp harvesting industry via their well-known role in controlling sea urchin populations; kelp is used in the production of diverse food and pharmaceutical products. Kelp are large Seaweeds ( Algae) belonging to the Brown algae and classified in the order Laminariales ^[128] Although human divers harvest red sea urchins both for food and to protect the kelp, sea otters hunt more sea urchin species and are more consistently effective in controlling these populations. The Red Sea Urchin is a Sea Urchin found in the Pacific ocean from Alaska to Baja California. ^[129] The health of the kelp forest ecosystem is significant in nurturing populations of fish, including commercially important fish species. ^[128] In some areas, sea otters are a popular tourist attraction, bringing visitors to local hotels, restaurants, and sea otter-watching expeditions. Tourism is Travel for Recreational or Leisure purposes The World Tourism Organization defines tourists as people who "travel ^[128]

Role in human cultures

Left: Aleut sea otter amulet in the form of a mother with pup. The Aleuts ( self-denomination from Aleut language allíthuh 'community' older or regional self-denomination Unangax̂, Unangan or An amulet ( the Elder|Pliny]] meaning "an object that protects a person from trouble" a close cousin of the talisman (from Arabic Above: Aleut carving of a sea otter hunt on a whalebone spear. Both items are on display at the St. Petersburg Museum of Anthropology and Ethnography. Saint Petersburg ( tr: Sankt-Peterburg,) is a city and a federal subject of Russia located on the Neva River The Peter the Great Museum of Anthropology and Ethnography is the major museum of Anthropology and Ethnography in St Petersburg, Russia. Articles depicting sea otters were considered to have magical properties. [130]

For many maritime indigenous cultures throughout the North Pacific, especially the Ainu in the Kuril Islands, the Koryaks and Itelmen of Kamchatka, the Aleut in the Aleutian Islands and a host of tribes on the Pacific coast of North America, the sea otter has played an important role as a cultural as well as material resource. ʔáinu (also called Ezo in historical texts are an ethnic group indigenous to Hokkaidō, the Kuril Islands, and much of Sakhalin. Koryaks (or Koriak are an indigenous people of Kamchatka Krai in the Russian Far East, who inhabit the coastlands of the Bering Sea to the south of the The Itelmen, sometimes known as Kamchadal, are an Ethnic group who are the original inhabitants living on the Kamchatka peninsula in Russia. The Aleuts ( self-denomination from Aleut language allíthuh 'community' older or regional self-denomination Unangax̂, Unangan or The Indigenous peoples of the Pacific Northwest Coast are the Pre-Columbian inhabitants of the Pacific Northwest Coast, their descendants and many Ethnic groups In these cultures, many of which have strongly animist traditions full of legends and stories in which many aspects of the natural world are associated with spirits, the sea otter was considered particularly kin to humans. Animism (from Latin anima ( Soul, Life) commonly refers to a religious belief that Souls or Spirits exist in Animals The Nuu-chah-nulth, Haida, and other First Nations of coastal British Columbia used the warm and luxurious pelts as chiefs' regalia. The Nuu-chah-nulth (pronounced) (also formerly referred to as the Nootka, Nutka, Aht, Nuuchahnulth) are one of the Indigenous peoples The Haida (19th C-early 20th C Indigenous nation of the west coast of North America. First Nations is a term of Ethnicity that refers to the Aboriginal peoples in Canada who are neither Inuit nor Métis people Sea otter pelts were given in potlatches to mark coming-of-age ceremonies, weddings, and funerals. A potlatch is a festival ceremony practiced by Indigenous peoples of the Pacific Northwest Coast in North America along Pacific Northwest coast of the United ^[50] The Aleuts carved sea otter bones for use as ornaments and in games, and used powdered sea otter baculum as a medicine for fever. The baculum (also penis bone, penile bone or os penis) is a Bone found in the Penis of most Mammals It is absent ^[131]

Sea otters at the Lisbon Oceanarium show their flexibility when grooming. The Oceanarium in Lisbon, Portugal ( Portuguese: Oceanário de Lisboa, pron.

Among the Ainu, the otter is portrayed as an occasional messenger between humans and the creator. ^[132] Versions of a widespread Aleut legend tell of lovers or despairing women who plunge into the sea and become otters. ^[133] These links have been associated with the many human-like behavioral features of the sea otter, including apparent playfulness, strong mother-pup bonds and tool use, yielding to ready anthropomorphism. Anthropomorphism is the attribution of uniquely Human characteristics to non-human creatures and beings natural and supernatural phenomena material states and objects ^[134] The beginning of commercial exploitation had a great impact on the human as well as animal populations – the Ainu and Aleuts have been displaced or their numbers are dwindling, while the coastal tribes of North America, where the otter is in any case greatly depleted, no longer rely as intimately on sea mammals for survival. ^[135]

Since the mid-1970s, the beauty and charisma of the species have gained wide appreciation, and the sea otter has become an icon of environmental conservation. ^[120] The round, expressive face and soft furry body of the sea otter are depicted in a wide variety of souvenirs, postcards, clothing, and stuffed toys. ^[136]

Aquariums and zoos

Sea otters can do well in captivity, and are featured in over 40 public aquariums and zoos. Animals that live under human care are in captivity. Captivity can be used as a generalizing term to describe the keeping of either Domesticated Animals ( Livestock An aquarium (plural aquariums or aquaria) is a Vivarium consisting of at least one transparent side in which Water -dwelling Plants A zoological garden, shortened to zoo, is an institution in which living animals are exhibited in captivity ^[137] The Seattle Aquarium became the first institution to raise sea otters from conception to adulthood with the birth of Tichuk in 1979, followed by three more pups in the early 1980s. The Seattle Aquarium is a public Aquarium located on Pier 59 on Seattle, USA 's Elliot Bay waterfront ^[138] In 2007, a YouTube video of two sea otters holding paws drew 1. YouTube is a video sharing website where users can upload view and share Video clips YouTube was created in February 2005 by three former PayPal employees 5 million viewers in two weeks, and currently has over 10. 5 million views. ^[139] Filmed five years previously at the Vancouver Aquarium, it was YouTube's most popular animal video at the time, although it has since been surpassed. The Vancouver Aquarium Marine Science Centre is a public Aquarium located in Stanley Park in Vancouver British Columbia, Canada. The lighter-colored otter in the video is Nyac, a survivor of the 1989 Exxon Valdez oil spill. The Exxon Valdez oil spill occurred in Prince William Sound, Alaska, on March 24 1989 ^[140]

Notes

References

• Kenyon, Karl W. (1969). The Sea Otter in the Eastern Pacific Ocean. Washington, D. C. : U. S. Bureau of Sport Fisheries and Wildlife.  
• Love, John A. (1992). Sea Otters. Golden, Colorado: Fulcrum Publishing. ISBN 1-55591-123-4.  
• Nickerson, Roy (1989). Sea Otters, a Natural History and Guide. San Francisco, CA: Chronicle Books. ISBN 0-87701-567-8.  
• Silverstein, Alvin; Silverstein, Virginia and Robert (1995). The Sea Otter. Brookfield, Connecticut: The Millbrook Press, Inc. . ISBN 1-56294-418-5.  
• VanBlaricom, Glenn R. (2001). Sea Otters. Stillwater, MN: Voyageur Press Inc. . ISBN 0-89658-562-X.  

External links

• Field notes by Georg Wilhelm Steller, 1742 (PDF)
• Live sea otter webcam – Monterey Bay Aquarium
• Live sea otter webcam – Vancouver Aquarium
• Otters holding hands – The popular YouTube video
• Precipice of Survival: The Southern Sea Otter (video)
• The Otter Project – Organization for protecting the California sea otter
• Friends of the Sea Otter