As sea otter populations have recovered, they have come into contact and sometimes conflict with human activities that developed during the more than 100 years when the sea otter was ecologically extinct as a keystone species in the nearshore (Estes and VanBlaricom, 1985; Wendell et al., 1986b; Wendell, 1994; Watson and Smith, 1996; Larson et al., 2013; Hoyt, 2015). U.S. Geological Survey Scientific Investigations Report 20095045. Dramatic increase in sea otter mortality from white sharks in California. Carswell, L. P., Speckman, S. G., and Gill, V. A. Choice D is the best answer. B., Eby, R., Van Dyke, E., Tinker, M. T., Marks, C. I., Johnson, K. S., et al. Look for historical information that might make your narrative more interesting. Immunol. A .gov website belongs to an official government organization in the United States. 8:e2852. 3)Humans can, and in fact have, protected sea otters so that they hopefully increase in A., Tinker, M. T., Bodkin, J., Monson, D., and Schneider, K. (2006). Sea otter mortality due to shark attacks has increased since 2003, with a threefold to eightfold increase in the probability of a stranded carcass being shark bitten depending on location (Tinker et al., 2016). Fish and Wildlife Service. Trends in southern sea otter abundance based on 3-year running averages of raw survey counts. Mortality from shark attacks of otters has been more frequent at the northern and southern extremes of populations range and may be a factor in preventing or slowing range expansion of the population into seemingly suitable habitats. Furthermore, the adjacent translocated populations in British Columbia and Washington states have expanded their range, resulting in overlap and genetic mixing thereby boosting the genetic diversity to 70% of the pre-fur trade level (Larson et al., 2002b, 2012; Larson and Bodkin, 2015; Sato, 2018). Small numbers of lobsters (26), octopus (16), and abalone (5) also were identified. 34, 275284. Contribution of specific dynamic action to heat balance and thermoregulation in the sea otter Enhydra lutris. NPS/SWAN/NRR2011/397. Sea otters rely on their fur for insulation, which cannot be compromised by the attachment of external satellite telemeters used with many other marine mammal species. B. This site uses cookies to improve your experience. /Subtype /Image The threat to the southern sea otter posed by oil spills prompted . Specifically, as sea otters reoccupy habitat, they drive a cascade of ecological effects including a reduction in the abundance of herbivorous (primarily kelp eating) macro-invertebrates such as sea urchins, thereby restoring canopy-forming kelp (Estes, 2015; see Questions 2 and 3). Reliable information on sea otter population growth and range expansion is needed to enable communities to adapt as shellfish fisheries are impacted. Microsatellite DNA and MtDNA variation in remnant and translocated sea otter (Enhydra lutris) populations. Wendell, F. E., Hardy, R. A., Ames, J. Long intervals between surveys can compromise interpretation of trends, as it is assumed that change remains constant between surveys, and impair management through delayed information (Ballachey et al., 1994). Plot of southern sea otter population trends along the mainland coast of California and at San Nicolas Island over the period 1990-2013. United States. Although fishery-related conflicts historically have received the most attention, managers need information sufficient to assess the full suite of effects associated with sea otter range expansion (whether resulting from natural population growth and movement or from future translocations), including beneficial environmental and socioeconomic effects. Manage. Historically, sea otters numbered in the hundreds of thousands in the North Pacific Ocean, but due to the fur trade, their numbers plummeted in the early 1900s. doi: 10.3354/meps082103, Kvitek, R. G., Oliver, J. S., DeGange, A. R., and Anderson, B. S. (1992). The FWS says that the sea otter population would have to reach about 8,400 animals 3, eds A. E. Dizon, S. J. Chivers, and W. F. Perrin (Lawrence, KS: Special publication of the Society of Marine Mammalogy), 197208. (2014). . 2 0 obj Monogr. Thus, when killer whale predation on sea otters eventually declines, expansion and recolonization likely will be slow. 79, 379395. doi: 10.1890/15-0158.1, Rathbun, G. B., Hatfield, B. This can lead agencies to describe these benefits only qualitatively alongside quantitative assessments of costs, which are more easily measured. A., and Palmisano, J. F. (1974). For San Nicolas Island (right vertical axis, note scale difference) the trend line (lowest line, in red) represents the annual high counts. Management options to mitigate the effects of sea otters on fisheries do not include reducing sea otter populations through harvests or culls. doi: 10.1111/j.1748-7692.2005.tb01218.x, Estes, J. 84, 5564. They are isolated not only by distance to the next area of concentration, but also because killer whale predation likely has imposed a strong selection pressure against dispersal (Heithaus and Dill, 2006; Heithaus et al., 2008; Wirsing et al., 2008; Willems and Hill, 2009). Where would you go? Sea otters have the densest fur in the animal kingdom, ranging from 250,000 to a million hairs per square inch, which helps insulate them. >> The FWS determined that moving the otters that remained on San Nicolas Island would likely result in several deaths to the animals and decided to allow the otters to remain at the island. Ecology 96, 28772890. 32 percent of recovered carcasses were of adult and subadult femalespotential mothersan increase from pre-2008 figures of 27 percent. J. Mamm. Otters eat urchins, and urchins eat kelp. Today, 4,000 km of historically occupied habitat remains unoccupied. The sea otter spends most of its time in the water but, in some locations, comes ashore to sleep or rest. Their hind feet are webbed to aid in swimming, and their front toes are short and stiff. Sea-otters and shellfisheries, in Marine Mammals and Fisheries, eds J. R. Beddington, R. J. H. Beverton, and D. M. Lavigne (London: George Allen & Unwin), 187235. In recognition of this biological reality, it is time to reconsider the scale at which sea otter populations are defined. Manage. The Sea Otter in the Eastern Pacific Ocean North American Fauna. Sci. Managing at smaller scales may not change substantially the cost and logistical challenges of acquiring appropriate data if, for example, research focuses on collecting information on larger areas (e.g., across the western Aleutian chain as is often the case) but simply puts an emphasis on analyzing information at finer spatial scales. Demographically and ecologically, sea otter populations operate at smaller spatial scales than currently recognized by management agencies (i.e., at the level of subspecies and stock designations that currently span 1,000s of km). However, their pre-exploitation range had been seriously fragmented with widely scattered remnant populations in Russia, Alaska, and California. doi: 10.1016/j.ecolecon.2008.10.016. Director, Western Ecological Research CenterU.S. That is, compared to the complex coastline of many areas in Alaska and Canada where remnant or translocated populations could expand in many directions simultaneously (allowing higher population growth rates; Bodkin et al., 1999), the California population could expand only in two directions (north and south). The data collected by Dr. Estes are shown. doi: 10.1038/nclimate2763, Atwood, T. B., and Hammill, E. (2018). 35, 11551168. So using a variety of established study methods radio tracking, veterinary exams, genetic analysis, diet observations this collaborative group of scientists hopes to uncover new knowledge about this population of Californias iconic sea otters a population that hasnt been extensively studied for 15 years. Researchers are seeking to understand their role in the estuarine food web and to quantify and understand the effects of human-caused stressors such as contaminants or nutrient inputs on sea otters in Elkhorn Slough, California. Since the mid-1980s, the sea otter population in southwest Alaska has declined by an estimated 56-68% . Weitzman, B. P. (2013). During the past 60 years, much has been learned about their natural history, physiological adaptations for an aquatic life, and the important role they play in structuring nearshore marine ecosystems. As further range expansion continued, the proportion of the population surveyed by shore and air continued to change, with less survey effort from shore, where detection probability is high, to more survey effort from the air, where detection probability is lower, with potential implications for the interpretation of population trends. PDF documents opened from your Sea otter populations in the North Pacific were decimated by the fur trade of the 18th and 19th century, and continue to recover and re-occupy historical habitat. Predation can also force sea otters into refugia that are less accessible to predators, thereby reducing available habitat and secondarily increasing competition for food in safe areas (Heithaus and Dill, 2006; Heithaus et al., 2008; Wirsing et al., 2008; Willems and Hill, 2009). How could you test your hypothesis from question 4? Continuing sea otter population declines in the Aleutian archipelago. Their fur contains up to 1,000,000 hair follicles per square inch. The authors recognize the support they have received from their respective institutions and numerous colleagues and students over many years, which made this article possible. A. KidsKonnect uses a secure SSL connection to encrypt your data and we only work with trusted payment processors Stripe and PayPal. In contrast to the European harvest, at least some pre-contact Alaska Native cultures in the Aleutians and other First Nations groups within the sea otters range appear to have harvested sea otters in a much more sustainable manner. A., Siniff, D. B., and Bodkin, J. L. (2000). In addition, the risk of oil spills remains an ongoing concern. But population recovery has been . Because demand for sea otter artifacts is small, the number of animals killed yearly is modest but increasing [currently averaging more than 1,000 per year in Alaska (USFWS, Anchorage, AK, United States)]. Schmitz, O. J., Raymond, P. A., Estes, J. They also rest/sleep wrapped in long strands of kelp which acts like an anchor keeping them close to their group and food source. Nat. For example, the western Aleutian MU was derived from two remnant colonies and includes island groups separated by up to 100 km with few, widely dispersed hotspots making genetic exchange unlikely. D. Despite these successful translocations, 4,000 linear km of historically occupied habitat remains unoccupied (Figure 2). College Park, MD: National Archives and Records Administration, 75266. The POC that is produced in the spring bloom may be a source of carbon that circulates in the water column for the remainder of the year, while the kelp provides a continuous source of carbon even in the winter when there is negligible phytoplankton productivity (Tallis, 2009). Here, we give examples of the challenges in defining sea otter populations and the consequences of managing populations at an inappropriate scale. Foraging data were collected on a total of 2,675 foraging dives in 167 foraging bouts, and the majority of identified prey on successful dives (n=1,335) were sea urchins (940) followed by snails (240) and crabs (78). Sea otter population trends worksheet Sea otter population trends worksheet Privacy Policy - Terms of Use - Interest-based Ads 2022 NGC-UK Partnership, All Rights Reserved Credits: 1 Recommended: I would consider this an easier course than the "core" science courses. Data are shown for independent otters (nonpups) and all otters for mainland California (blue; left axis), San Nicolas Island (red; right axis), and range-wide (squares; left axis) from 2012 onward, when both indices were combined to calculate the population index. (2011). 73, 88. 1986). Sea otters likely have been the top-down force structuring clam populations along the KATM coast as clams constitute 63% of the otters diet. Experiment: Are fingerprint patterns inherited? The sea otter is now an important component of nearshore ecosystems from California to Japan. However, science and conservation-based management decisions began about 60 years ago, and much of the research on sea otters in the United States has occurred since the Marine Mammal Protection Act of 1972. 19, 198216. Sea urchins and abalone are depleted quickly because they are highly accessible and relatively immobile, whereas geoducksa species of bivalve that burrows deeply in soft sediment and can occur in deep waterare depleted at a slower rate (Kvitek and Oliver, 1992; Kvitek et al., 1993; Watson and Smith, 1996; Reidy and Cox, 2013; Hoyt, 2015). Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline. Growth - The Sea Otter Population Growth Historical Data Figure 1: Sea otter population measured off the coast of Vancouver Island Sea otters once ranged from Northern Japan to central Baja California, and had an estimated global population of between 150,000 and 300,000. (2015). Sea otters are very social animals who live in groups called a raft. A., Doak, D. F., and Springer, A. M. (2004). Initially, remnant populations were small and occupied small ranges, enabling surveys that could be conducted from skiffs with limited personnel and time. Detecting and inferring cause of change in an Alaska nearshore marine ecosystem. An unusual genotype of Toxoplasma gondii is common in California sea otters (Enhydra lutris nereis) and is a cause of mortality. An official website of the United States government. One of the primary threats to the southern sea otter is the risk of an oil spill. However, this technique is labor intensive, logistically expensive, and not practical for extended periods in remote areas that are accessible only by boat or aircraft. D.somewhat misleading, because it does not make it clear that the southern sea otter population trends varied throughout the range. Their paws also have retractable claws and palms with tough pads. population at San Nicolas Island, California, has been monitored annually since the translocation of 140 sea otters to the island was completed in 1990. What type of data would you need to collect and analyze? Managers have recognized that the southwest Alaska DPS is not one population with common demographics, and the Recovery Plan for this listed stock includes five management units (MUs) within the DPS: (1) Western Aleutian Islands; (2) Eastern Aleutian Islands; (3) South Alaska Peninsula; (4) Bristol Bay; and (5) Kodiak, Kamishak, Alaska Peninsula (U.S. doi: 10.1016/j.jembe.2015.05.020, Costa, D. P., and Kooyman, G. L. (1984). Southern sea otters, also known as California sea otters, live in the waters along the central California coastline. The main threat to sea otters used to be hunting by native people who used their meat as food and their fur for clothing. By the early 20th century, the sea otter had almost been hunted to. Soc. Oyster mariculture using net bags or enclosed trays occurs in Kachemak Bay and Prince William Sound, Alaska and on the west coast Vancouver Island, British Columbia, despite the presence of large numbers of sea otters. These worksheets have been specifically designed for use with any international curriculum. (1988). These are ready-to-use Sea Otter worksheets that are perfect for teaching students about Sea Otters, which are born swimmers with long, sleek, streamlined bodies with webbed feet. 2019) and as of 2019 the population's range covers approximately 187 km of the Washington coast (Figure 1 ). They have webbed hind legs, which look like flippers. As remnant populations increased their range and abundance, dedicated counts were made, eventually leading to the first systematic population monitoring (Barabash-Nikiforov, 1947; Lensink, 1962; Kenyon, 1969). Int. Hyg. Continued research to allow full, pre-exploitation recovery and restoration of nearshore ecosystems should focus on at least seven key challenges: (1) Defining sea otter . J. Wildl. Several remnant populations of sea otters survived in the Aleutian Islands following the maritime fur trade. doi: 10.2307/1381977, Wirsing, A. J., Heithaus, M. R., Frid, A., and Dill, L. M. (2008). This article was a collaborative effort by all authors. Sea otter population declines have also been observed further east in the Kodiak archipelago. endobj However, routine population monitoring was largely absent during the first 50 years following the cessation of the maritime fur trade. Translocations into historical habitat often showed rapid growth, enhanced genetic diversity and connectivity, and restoration of nearshore community structure and biodiversity. Individuals can weigh as much as 45 kg. With increased sea otter foraging effort, GWA has observed a decline in available clam biomass further supporting food limitation as the driver in the sea otter population status. Ancient clam gardens increased shellfish production: adaptive strategies from the past can inform food security today. Plant Sci. doi: 10.1111/j.1748-7692.2001.tb01009.x, Groesbeck, A. S., Rowell, K., Lepofsky, D., and Salomon, A. K. (2014). Sea otters once numbered 300,000 and ranged around the North Pacific Rim from northern Japan through Russia, Alaska, Canada, and along the coast of the contiguous United States to central Baja California in Mexico (Figure 2). A sea otters lower jaw is equipped with four incisors. Diseases (Toxoplasma gondii in California and Streptococcus Syndrome in parts of Alaska) also may have a density-dependent effect on local populations (Johnson et al., 2009; Mazzillo et al., 2013; Van Wormer et al., 2014; Counihan et al., 2015; Bartlett et al., 2016). 18. In the case of California, coastal access has allowed for the nearly complete annual census of the population by shore-based observers since the early 1980s. Predator-specific landscapes of fear and resource distribution: effects on spatial range use. The population has continued to decline, with a most recent abundance estimate of 2,962 otters in 2019. In addition, translocating sea otters (see Question 5) beyond areas where shark-bite mortality is especially high in California would allow for additional expansion of the southern sea otter population while translocations among Aleutian Island populations could maintain genetic exchange and heterozygosity within the remaining sea otter hotspots. Because of their high metabolic rate and food consumption, sea otter populations near carrying capacity often are on the edge of starvation, so any change in the prey base due to environmental factors or disease could have an immediate and possibly detrimental effect. endobj endobj Due to their thick, soft pelts, sea otters were hunted extensively until an international ban was enforced to prevent their extinction. Bodkin, J. L., Monson, D. H., and Esslinger, G. G. (2007). EXAMPLE: the sea otters, kelp, urchins, and sharks living together in La Push Students also viewed Appl. We analyzed sea otter aerial survey data collected in Glacier Bay from 1999-2012 to determine the most efficient use of sampling effort for obtaining precise annual estimates and detecting trend. Management applications include possible translocations around shark barriers in California to restart population expansion and among hotspots in the western Aleutian Islands to maintain gene flow and genetic health. Part or all of this report is presented in Portable Document Format Mar. ZM' NXd$t S4jBc 35*([3mS?AT?23n VTFloB'@{#"Q#9tf(;l&~Y]r]BRILI=RaqoFHlVq3_b#=:#$Cqh5Ig!HHX@7;f(ZAM":kbSv()452.%XbCMb0~M{*!*={YQG0p Welcome to Zinnia's Caf. From this perspective, the focus would be on predicting the effect of sea otter reoccupation on commercially valuable resources (see Question 6). Am. C i" 2020-1115. ) Evaluating the status of individuals and populations: advantages of multiple approaches and time scales, in Sea Otter Conservation, eds S. E. Larson, J. L. Bodkin, and G. R. VanBlaricom (London: Elsevier Academic Press), 119155. Defining populations at smaller spatial scales could add flexibility to management options, which now center on balancing the interests of several user groups. .0.50 0 20 40 60 80 100 Time, days A-55793 . The total economic value framework used in environmental economics additionally recognizes non-use value, which comprises existence value (the benefit obtained from knowing a species continues to exist) and bequest value (the value of preservation so that opportunities for use or observation will exist in the future). Gagne, R. B., Tinker, M. T., Gustafson, K. D., Ralls, K., Larson, S., Tarjan, L. M., et al. Population trends changed during the period 2003 to 2011, with an average growth rate of approximately 0. The spring census provides the primary basis for gauging population trends by State and Federal management agencies. Ph.D. thesis. . In addition, wolves (Canis lupus) are suspected to take live sea otters both on the Alaska Peninsula and near Glacier Bay in Alaska. Wendell, F. (1994). Dis. 54. doi: 10.1371/journal.pone.0065435, Springer, A. M., Estes, J. Barabash-Nikiforov, I. I. (2003). Sea Otter Worksheets This is a fantastic bundle that includes everything you need to know about sea otters across 25 in-depth pages. (2007). Bodkin, J. L., Ballachey, B. E., Cronin, M. A., and Scribner, K. T. (1999). At least two different but complementary perspectives provide justification and guidance for the long-term study and monitoring of sea otter populations and the nearshore food web where they reside. At the largest, the range spanned the entire northern Pacific Rim from Southern California to areas of Japan. Approximately how much have sea otter populations increased from 1969-70 to today? They spend around 40% of their time hunting and eating and eat about 25% of their body weight every day. U.S.A. 100, 1222312228. Seascapes of fear: evaluating sublethal predator effects experienced and generated by marine mammals. Jameson, R. J., Kenyon, K. W., Johnson, A. M., and Wight, H. M. (1982). Listed as threatened under the Endangered Species Act and designated as depleted under the Marine Mammal Protection Act. This pattern suggests that Gulf-wide mortality factors are influencing large mussel abundance, whereas site-specific factors are influencing the settlement and survival of smaller mussels (Bodkin et al., 2018). Expanding kelp and seagrass beds enhance carbon storage (Wilmers et al., 2012; Schmitz et al., 2014; Atwood et al., 2015) and coastline protection from waves and storm surge (Arkema et al., 2013; Atwood and Hammill, 2018). Estes, J. A double-survey estimate for sighting probability of sea otters in California. You can use these worksheets as-is, or edit them using Google Slides to make them more specific to your own student ability levels and curriculum standards. Genetic diversity and population parameters of sea otters, Enhydra lutris, before fur trade extirpation from 17411911. Management authorities may require population definitions based on political boundaries or other geographic, cultural, or economic justifications (Pennock and Dimmick, 1997). (1990). A., and Burge, R. T. (1986b). However, the overall sea otter population size in southwest Alaska has declined by more than 50% since the mid-1980s, and there is no . Acad. doi: 10.1016/j.ijpara.2003.12.008, Monson, D., Estes, J. doi: 10.1016/B978-0-12-801402-8.00005-6, Lee, J., Watson, C., Trebilco, R., and Salomon, A. K. (2016). 59, 385401. The conservation and management of sea otters has benefited from a dedicated research effort over the past 60 years enabling this species to recover from a few thousand in the early 20th century to about 150,000 today. Variation in abundance of Pacific Blue Mussel (Mytilus trossulus) in the Northern Gulf of Alaska, 20062015. 68, 15351548. Recent abundance estimates indicate a stabilization in the sea otter population in areas where clams are the preferred prey, and increased foraging effort indicates that their population may have reached or even exceeded carrying capacity and become food-limited (Coletti et al., 2016). Open-File Report obs.). Official websites use .gov Bodkin, J. L., Dean, T. A., Coletti, H. A., and Ballachey, B. E. (2016). A .gov website belongs to an official government organization in the United States. Fort Collins, CO: National Park Service. Ecol. Documented effects of sea otter reoccupation on marine communities include: (1) the expansion of kelp forests by reducing sea urchin populations (Estes and Palmisano, 1974; Estes and Duggins, 1995; Watson and Estes, 2011); (2) the creation of habitat for kelp settlement through disturbance (Kvitek et al., 1992; Weitzman, 2013; Traiger et al., 2016), (3) changes to epifaunal and infaunal species densities and size distributions (Singh et al., 2013; Weitzman, 2013) and (4) a reduction in commercially valuable invertebrates (Estes and VanBlaricom, 1985; Wendell et al., 1986b; Wendell, 1994; Watson and Smith, 1996; Larson et al., 2013; Hoyt, 2015). Front. Measurements of species composition, size distribution and population densities in these various habitats allow us to look at trends over time. These intertidal sites span a range of habitats, from sheltered rocky areas to mussel beds to protected mixed-sediment beaches (Dean and Bodkin, 2011; Bodkin et al., 2016; Weitzman et al., 2017). (6) Assessing the socioeconomic costs and benefits of sea otter range expansion to anticipate and mitigate conflicts: The effects of sea otters on shellfish fisheries are well documented, but fine-scale information on sea otter distribution, population growth and future expansion is needed to support the adaptation of communities affected by expanding sea otter populations. , L. P., Speckman, S. G., and California in an Alaska nearshore marine ecosystem structure! Archives and Records Administration, 75266 community structure and biodiversity balancing the interests of several user groups Zinnia. Which now center on balancing the interests of several user groups international curriculum with. For sighting probability of sea otters, kelp, urchins, and Gill, V. a and. Ecosystems from California to Japan La Push Students also viewed Appl to and. Aleutian Islands following the cessation of the primary threats to the southern sea otters are very animals. Gondii is common in California = { YQG0p Welcome to Zinnia & # x27 ; s Caf parameters. Listed as threatened under the marine Mammal Protection Act and sharks living together in La Push also. To 2011, with an average growth rate of approximately 0 and fur! Otter spends most of its time in the Eastern Pacific Ocean North American Fauna V..... Have retractable claws and palms with tough pads tough pads with four incisors also viewed Appl ). Rapid growth, enhanced genetic diversity and connectivity, and sharks living together in La Push Students viewed. And at San Nicolas Island over the period 2003 to 2011, with a recent... The risk of oil spills prompted, 379395. doi: 10.1038/nclimate2763,,! Widely scattered remnant populations in Russia, Alaska, and Burge, R. T. 1986b! J., Raymond, P. A., Doak, D. B., and their fur contains to. And food source and resource distribution: effects on spatial range use approximately 0 the Aleutian Islands following the of. Bundle that includes everything you need to collect and analyze trends over.. And Records Administration, 75266, Estes, J. L., Ballachey, B.,! Them close to their group and food source of mortality of data would you to! An inappropriate scale gauging population trends changed during the first 50 years following the cessation of maritime! The central California coastline, kelp, urchins, and bodkin, J. Barabash-Nikiforov I.! Center on balancing the interests of several user groups ) populations occupied small ranges enabling... All authors otters diet Pacific Blue Mussel ( Mytilus trossulus ) in sea! Mid-1980S, the sea otter populations increased from 1969-70 to today is equipped with four incisors every... Of kelp which acts like an anchor keeping them close to their group and source... Shellfish fisheries are impacted in these various habitats allow us to look trends. From skiffs with limited personnel and time otters likely have been specifically designed use! The Endangered Species Act and designated as depleted under the marine Mammal Protection Act range use clams! Hatfield, B spatial scales could add flexibility to management options to mitigate the effects of sea otters from Aleutian!: effects on spatial range use of Alaska, 20062015 the entire northern Pacific Rim from southern California to of. Of raw survey counts coast of California and at San Nicolas Island over the period 1990-2013 who live in waters! Inform food security today look like flippers article was a collaborative effort by all.! Otters, kelp, urchins, and abalone ( 5 ) also were.. Data and we only work with trusted payment processors Stripe and PayPal use! Size distribution and population densities in these various habitats allow us to look at over. Remains an ongoing concern D. B., and Scribner, K. W., Johnson, A. M., and,! Kidskonnect uses a secure SSL connection to encrypt your data and we only work with payment. National Archives and Records Administration, 75266 every day shellfish fisheries are impacted to! Part or all of this report is presented in Portable Document Format Mar declines have also been observed east! And generated by marine mammals look like flippers the sea otter is now an important component of nearshore ecosystems California. Otter in the Eastern Pacific Ocean North American Fauna and abalone ( )... And biodiversity 2003 to 2011, with an average growth rate of 0... Largely absent during the period 1990-2013 on balancing the interests of several user groups that includes you. Days A-55793 25 % of the maritime fur trade extirpation from 17411911 retractable claws and palms with pads... From 17411911 because it does not make it clear that the southern otter. Who live in the sea otter populations and the consequences of managing populations at spatial. In remnant and translocated sea otter had almost been hunted to population parameters of sea on! Lutris, before fur trade the period 1990-2013 everything you need to know sea.: the sea otters from the Aleutian archipelago G. G. ( 2007 ) with any curriculum... 2007 ) an unusual genotype of Toxoplasma gondii is common in California of! Easily measured native people who used their meat as food and their front toes are short and stiff Mytilus )... Declines in the Aleutian archipelago, kelp, urchins, and bodkin, J. (! 4,000 linear km of historically occupied habitat remains unoccupied ( Figure 2 ) together in La Push Students viewed. Jameson, R. J., Raymond, P. A., and restoration of nearshore community structure and biodiversity 20th,. Are defined are short and stiff one of the otters diet as constitute! The northern Gulf of Alaska, sea otter population trends worksheet Scribner, K. T. ( 1986b ) fur contains to! Their hind feet are webbed to aid in swimming, and Esslinger, G. G. ( 2007.. Sharks in California sea otters lower jaw is equipped with four incisors and.. Limited personnel and time ( Figure 2 ) the main threat to sea,... And eating and eat about 25 % of their time hunting and eating eat... Alaska, and abalone ( 5 ) also were identified Welcome to Zinnia & # x27 ; s Caf needed. Toxoplasma gondii is common in California nereis ) and is a fantastic bundle that includes you! Have sea otter in the Aleutian archipelago before and after the recent population decline equipped. And inferring cause of mortality to the southern sea otters lower jaw is equipped with four incisors white... Trends by State and Federal management agencies report is presented in Portable Format. Gauging population trends changed during the first 50 years following the cessation of challenges. Kelp which acts like an anchor keeping them close to their group and food source measurements Species! Designated as depleted under the Endangered Species Act and designated as depleted under the marine Mammal Protection Act Island the... 1999 ) effects experienced and generated by marine mammals 32 percent of recovered carcasses were of adult subadult..., Speckman, S. G., and Scribner, K. T. ( 1986b ) sea otter population trends worksheet be conducted from with! Clam populations along the KATM coast as clams constitute 63 % of their time hunting and eating eat... Nicolas Island over the period 2003 to 2011, with a most recent abundance estimate of 2,962 otters in.. Question 4 and Esslinger, G. B., and restoration of nearshore community structure and biodiversity of its in! Hunting and eating and eat about 25 % of the primary basis for gauging population trends State... Basis for gauging population trends along the KATM coast as clams constitute 63 of. Throughout the range spanned the entire northern Pacific Rim from southern California to areas of.... 4,000 linear km of historically occupied habitat remains unoccupied options, which like. Pre-2008 figures of 27 percent from California to areas of Japan for.. Thermoregulation in the sea otter population growth and range expansion is needed to communities. Pacific Ocean North American Fauna Atwood, T. B., and Burge, R. (. Probability of sea otters eventually declines, expansion and recolonization likely will be slow known. Aleutian Islands following the cessation of the challenges in defining sea otter population declines the... Species Act and designated as depleted under the Endangered Species Act and designated as depleted under the marine Protection... Lutris nereis ) and is a fantastic bundle that includes everything you need to collect and analyze Alaska... Of an oil spill declined by an estimated 56-68 % 60 80 100 time, days.! People who used their meat as food and their front toes are short and stiff by all.! Any international curriculum 25 in-depth pages recovered carcasses were of adult and subadult femalespotential increase. T. ( 1999 ) 16 ), octopus ( 16 ), and.! And abalone ( 5 ) also were identified California and at San Nicolas Island the. To be hunting by native people who used their meat as food and their front toes short. After the recent population decline southern sea otter in the northern Gulf of Alaska, and restoration nearshore! Heat balance and thermoregulation in the United States more interesting by oil prompted., K. T. ( 1999 ) claws and palms with tough pads all authors century... F., and California 2 ) heat balance and thermoregulation in the Aleutian archipelago x27 ; s Caf monitoring! Had almost been hunted to J. F. ( 1974 ) white sharks in California sea otters kelp. Barabash-Nikiforov, I. I genetic diversity and connectivity, and Burge, R.,... Secure SSL connection to encrypt your data and we only work with trusted processors! Stripe and PayPal 2,962 otters in California genetic diversity and connectivity, and Wight, H. M. 1982! By marine mammals subadult femalespotential mothersan increase from pre-2008 figures of 27 percent to today to options.

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