These codes of practice and regulatory tools may assist in mitigation of effects to Steller Sea Lion habitat. The western population numbered approximately 150,000 animals in the 1950s but has since declined precipitously, with current numbers estimated at approximately 39,500. Steller Sea Lions in Canada and neighbouring waters were subjected to predator control programs during most of the 20th century. 1994a), but sea lions were observed in the vicinity of the oil spill and metabolites in the blood showed they had been exposed to hydrocarbons. methyl hydrates) have the potential to disturb animals as they produce both chronic (i.e. Because natural oceanographic changes can neither be predicted nor controlled, management authorities may have no choice but to focus on understanding and minimizing anthropogenic risk factors, despite the political consequences, in order to reduce the probability of eventual extinction. The thin blue lines show the distribution of animals among main breeding areas in B.C. The first and fifth toes are longer than the three middle toes, and the first toe, or hallux, is longer and wider than the fifth toe. Prior to the species being protected in the 1970s, the Canadian government conducted intensive culls of Steller Sea Lions at rookeries, for the mandated purpose of protecting salmon fisheries (Figure 4). There are four main breeding areas in B.C. 1998) provides further evidence of nutritional stress during the steep declines in the Western Population observed during the 1980s (NMFS 2008). Throughout their range they are usually found from the coast to the outer continental shelf and slope. As mentioned above, severity of population level impact is low for haulouts, but moderate for disturbance to rookeries due to site fidelity, potential energetic costs for mothers and pups, and pup survival (Table 1). (b) Trends in sea lion pup counts in southeastern Alaska. In addition to fish, squid and octopus are sometimes consumed, but their importance was likely exaggerated in earlier studies because cephalopod beaks likely accumulate in stomachs over extended periods (Bigg and Fawcett 1985). The centre of distribution of the breeding population on the west coast of North America has shifted northward from the Columbia River (46.0ºN) in the 1920s to central B.C. Commercial harvests of subadult male northern fur seals (Callorhinus ursinus) took place on the Pribilof Islands from the time of their discovery in 1786 until 1984. However, many of the 100 or so salmon farms currently operating in B.C. Longevity is 20 years in males and up to 30 years in females. Andrey Narchuk Asia Kamchatka marine mammals ocean Pacific Pacific ocean Russia sea sea lion Steller sea lion underwater. herring to gadids) may affect sea lion vital life history parameters (Trenberth 1990; Springer 1998; Benson and Trites 2002; Trites et al. Anthropogenic stressors can also increase the incidence of disease, or introduce foreign pathogens into the population. California sea lions appear to have displaced Steller Sea Lions from traditional rookeries in the Channel Islands off California, and have extended their non-breeding range north into B.C. Large bounty kills were also made in Oregon in the 1920s (Pearson and Verts 1970), and harassment and killing by bounty hunters and fisherman also reduced abundance of Steller Sea Lions and apparently eliminated several breeding sites in California (Rowly 1929). Over 50 species of fish and invertebrates have been identified in the diets of Steller Sea Lions (Wilke and Kenyon 1952; Pike 1958; Spalding 1964; Pitcher 1981; Kastelein et al. (modified from Loughlin 1997 and Sease et al. Chronic noise stress in important foraging areas and near rookeries could have a long-term effect on Steller Sea Lion vital rates and body conditions; however, given the remote locations of rookeries at present, concern remains low (Table 1). Preliminary calculations indicate that even if killer whale predation accounted for all natural mortality, the net annual production of Steller Sea Lion populations in B.C. A juvenile that still has a lot of growing-up to do. York (1994) using two age-structure samples with their estimated survival and fecundity rates and counts of Steller sea lions from aerial surveys suggested that the early decline was mostly caused by a decline in juvenile survival. Éva E. Plagányi, Douglas S. Butterworth, in Encyclopedia of Marine Mammals (Second Edition), 2009. L'animal est donc reparti sans blessure. Mate, B.R. Historical counts of Steller Sea Lion rookeries in B.C. 2000; Benson and Trites 2002; Fritz and Hinkley 2005; Trites et al. may have contributed to the rapid expansion of new rookeries established in SE Alaska (Calkins et al. Because PBDEs resemble PCBs, it is likely that PBDEs will be increasingly recognized as a threat to the health of wildlife, including Steller Sea Lions. Several lines of evidence favor the argument that ecosystem change has contributed to the decline in sea lion numbers. A group of western Steller sea lions with many juveniles, subadults, and small adult males. Numbers on rookeries in B.C. Acoustic Disturbance in Aquatic HabitatOperations related to oil and gas exploration, alternative energy development (e.g. Decline of the Steller sea lion in Alaskan waters : untangling food webs and fishing nets. carnívors > pinnípedes > otàrids; Traduccions 1997, 2003; Raum-Suryan et al. 1983; Merrick and Loughlin 1997). However, recent genetic sampling indicates two newly established rookeries near the western edge of the Eastern Population may have been colonized by a mixture of Western and Eastern stock animals (O’Corry-Crowe et al. Genetic data have been used as the basis for dividing the species into two populations, western and eastern, with the boundary at Cape Suckling (144° W longitude), Alaska. Steller Sea Lions are top marine predators. 1996; Melin and DeLong 2000). Historically, the Western Population (Russia to Gulf of Alaska) was much larger than the Eastern Population (southeast (SE) Alaska to California), and accounted for roughly 90% of total abundance between the 1950s and 1970s (Kenyon and Rice 1961; Loughlin et al. Thus, Steller Sea Lion reproductive biology may not have the plasticity to adapt to disturbances near breeding colonies. The concern for impacts on population viability from regime shift or climate change is moderate. Overall prey availability and regional species composition may be altered by natural or anthropogenic factors, and fisheries management will need to balance the needs of a continually growing Steller Sea Lion population with that of fisheries. British Columbia. Canada uses a management scheme referred to as “Objective Based Fisheries Management.” They have identified upper and lower reference points of 30 and 70% of the historical maximum population. Weaning often takes place before the next breeding season, but it is not unusual to see females nursing yearlings, older juveniles, or multiple offspring. The only portion of the Eastern Population range that escaped large culls was southeast Alaska, where there are no records of the species breeding or being abundant in the early 1900s. Several viability analyses have been applied to Steller's sea lion population data. Because natural oceanographic changes can neither be predicted nor controlled, management authorities have no choice but to focus on understanding and minimizing anthropogenic risk factors, despite the political consequences, in order to reduce the probability of eventual extinction. In addition to being larger, males have a mane of longer guard hairs extending from the back of the head to the shoulders and all around the neck. Recent rulings in US federal courts have restricted fishing activity in some locations and seasons for the purpose of reducing the rate of decline, intensifying the associated political debate. 1996). This is in contrast to the side-to-side head wave of California sea lion males when they produce their characteristic repetitive bark. The eyes are widely-spaced apart, and set well back from the end of the muzzle and, like the ear pinnae, appear small when compared with the size of the head. Adult fur color varies between a light buff to reddish brown with most of the under parts and flippers a dark brown to black; naked skin is black. They posit that, paradoxically, Steller sea lion and northern fur seal (Callorhinus ursinus) populations might realize greater benefits if adult pollock and large flatfish were more heavily fished. 2006). Rates of entrapment in finfish aquaculture installations are currently reported via voluntary means in the Pacific Region, which may limit the information regarding these types of interactions. The Steller Sea Lion is the largest member of the eared seals, or sea lions and fur seals (Order Carnivora, Superfamily Pinnipedia, Family Otariidae; Rice 1998). steller's eider. Steller sea lions sometimes leave their haulouts in large groups of over 1000 individuals; however, sightings at sea are most often of groups of 1 to 12 animals . 2004). 2003, 2007), and dispersal patterns appear to have changed over time. The red dotted line separates the range of the Western Stock from that of the Eastern Stock. and consume the same prey species (Olesiuk and Bigg 1988). 1990; Olesiuk 1999; Bowen et al. Province-wide aerial surveys have been conducted in B.C. Lion de mer de Steller. Steller's sea lions occur in coastal waters of the North Pacific Rim from southern California to northern Japan and in the Bering Sea and Sea of Okhotsk. In B.C., there have been few systematic studies of contaminant levels in Steller Sea Lions, although studies have recently been initiated to evaluate PCBs and PBDEs. The population decline in the Aleutian Is. 2002). California sea lions migrating along the coast of Oregon appear to displace Steller Sea Lions (Mate 1975); the two species often share the same winter haulout sites (P. Olesiuk pers. (DFO 2008), it is unlikely that this threat currently impacts population viability (Table 1). Steller sea lion. The scientific name (Eumetopias jubatus) means having a broad forehead and a mane, a reference to the prominent ruff of coarse hair that mature males develop on their necks and chests, from which is also derived the name ‘lion’. Western Steller sea lion, Aleutian Islands. About 70 percent of the Steller sea lion population resides in Alaska. In addition, because animals concentrate at a limited number of breeding sites, they may be more vulnerable to both catastrophic accidents, or localized threats affecting early survival (e.g. The only licences issued that allow for killing of sea lions have been to protect stocks at fish farms and herring impoundments from predation. The acute impacts that reduced prey availability can have on pinnipeds is evident from the abrupt declines in California sea lion and northern fur seal pup production on San Miguel Island coinciding with El Niño events (DeLong and Antonelis 1991; Melin and DeLong 1994; Melin et al. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. Pups are born from May through July, and females stay continuously ashore with their newborns for the first week to ten days after giving birth. Although parasites and diseases may have little impact on otherwise healthy animals, effects could become significant if combined with other stresses (Haebler and Moeller 1993). 1996). troll vs. seine nets) in terms of risk of entanglements, The spatial and temporal distribution of fisheries with respect to important sea lion haulouts and rookeries, as well as the frequency of fisheries interactions, illegal kills or entanglement incidents. 10). The seasonal abundance and distribution of prey species is also poorly understood, as are potentially important foraging areas. Le lion de mer de Steller, l'otarie à fourrure de l'Alaska, l'éléphant de mer, la loutre [...] d e mer , l'épaulard et le dauphin sont parmi les autres espèces qui bénéficient des soins du centre. In addition to the four breeding sites, there are about twenty-three haulout sites distributed mainly along the exposed outer coast that are used continuously throughout the year, as well as numerous winter sites used on a seasonal or irregular basis. Adult males arrive at the rookeries before females, and those that are nine years or older, fight for and often obtain a territory, which they aggressively and vociferously defend. Diving ability of pups and juveniles increases with age, and they routinely dive to depths of around 140 m for periods of 2 min as yearlings. Essential haulout features seem to include relatively flat terrain, accessibility, protection from swell and waves, and absence of terrestrial predators such as bears and wolves (Edie 1977). Follow. Mitigation potential refers to the likelihood that measures (future or existing) may mitigate or prevent negative effects to the population. The rate of decline has varied over time, with the highest rates (approximately 15% per year) from 1985 until 1990. Resolution of the question of cause has become the focus of intensive political interest because of the potential economic consequences. Figure 4: Total Numbers of Steller Sea Lions Reported to have been Killed in B.C. The maximum size of the subsistence take is set by the PBR approach at about 15,000 animals, well above the mean annual take from 2000 to 2004 of 750 animals. Adult male western Steller sea lion hauled out with northern fur seals. Sea lions use protected areas during storms, and wet areas during extremely hot weather (Edie 1977). By continuing you agree to the use of cookies. For instance, severely depleted populations of California sea lions sustained exponential growth rates of only about 6.1% (Lowry and Maravilla-Chavez 2005) and northern fur seals about 8.6% per year (York, pers. At the Sea Otter Group rookery, in spite of intense annual culls, animals continued to use the rookery for 17 years before the colony was completely eradicated. Numbers of other piscivores in the habitat, including seabirds and harbor seals, have declined over a similar timescale in many parts of the sea lion range. coast, the potential threat of accidental spills is one of local depletion, as opposed to impacting the entire population. With the exception of First Nations peoples, no person can fish for or disturb any marine mammal, unless explicitly authorized by a licence. The offshore distribution of Steller Sea Lions is not well defined. comm.). Approximately half of the sites were noted to exist during the first surveys in 1913 (Newcombe and Newcombe 1914), while about one-quarter appear to have been colonized since aerial surveys were initiated in the early 1970s. Considering that over 70% of pup production in B.C. Limiting factors are the natural processes that limit population size or growth. Both populations are designated “endangered” as per RLTS. Given the low level of current reported kills, the level of concern for this threat is currently assessed as negligible (Table 1). Parler aux habitants de Reflet-de-Lune pour obtenir des indices quant à l’endroit où ces objets se trouvent.Reformer le Pendentif du lion de mer à partir des deux moitiés. The Steller Sea Lion breeding colony at Cape St James is located within the Gwaii Haanas National Park Reserve and Haida Heritage Site, cooperatively administered by the Parks Canada Agency and the Council of the Haida Nation. Adult females tend to dive deeper in winter than summer. In 2004, license conditions were modified to remove Steller Sea Lions from the permits to eliminate the use of lethal control for this species due to the COSEWIC designation of this species as special concern. The species is gregarious while on land, and animals gather at traditional rookeries and haulout sites, some of which have been used for over a century. 2000; NMFS 2001; Gallucci et al. Continued communication with First Nations groups interested in harvesting pinnipeds will assist in assessing future level of concern for population-scale impacts due to harvest.

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