Secure .gov websites use HTTPS Census counts may be made from shore, the water or the air. doi: 10.3354/meps08138, Tarjan, L. M., and Tinker, M. T. (2016). Sea otters serve as sentinels for protozoal pathogens transmitted from the terrestrial hosts to marine mammals. Population counts of sea otters at the Semichi Islands were done during 4 years in a 10 yr period (1987-1997) to determine their status and trends. Population genetic studies of the sea otter (Enhydra lutris): a review and interpretation of available data, in Molecular Genetics of Marine Mammals, Vol. J. Wildl. An increased emphasis should be placed on quantifying the beneficial socioeconomic effects of sea otters (e.g., ecotourism) and sea otter-induced trophic cascades in kelp and seagrass habitats (e.g., benefits to finfish fisheries resulting from increases in finfish populations, increases in atmospheric carbon sequestration, and reduced shoreline erosion). Sea otters have a high metabolism. White shark (Carcharodon carcharias) related mortality has long been identified as a barrier to the northward expansion of the southern sea otter population in California. J. Parasitol. Diet A sea otter has a metabolic rate much higher than most mammals of similar size, and must consume large quantities of food. Gorbics, C. S., and Bodkin, J. L. (2001). Society for Science & the Public 20002023. An unusual genotype of Toxoplasma gondii is common in California sea otters (Enhydra lutris nereis) and is a cause of mortality. (2007). By helping to maintain viable sea urchin populations, the sea otters are also allowing enough kelp to grow and act as a habitat for other organisms.Suppose that a bacterial infection swept across a sea otter population and killed most sea otters before they could reproduce. /BitsPerComponent 8 your claim with the current data on kelp? (2018). Provide a title and lable both the X and Y. (2017). We attempt to assign a cause to observed changes by contrasting top-down (sea otter foraging efficiency and prey abundance) and bottom-up (recruitment, growth rates and environmental metrics such as temperature) processes among the four regions and the scale at which changes occur (e.g., similar changes across all areas vs. changes observed asynchronously among regions). Both perspectives will benefit from a multi-faceted approach to monitoring not only sea otters, but the nearshore ecosystems they occupy. A lock () or https:// means youve safely connected to the .gov website. The History and Status of Sea Otters in Alaska. Sea otters likely have been the top-down force structuring clam populations along the KATM coast as clams constitute 63% of the otters diet. An official website of the United States government. Following their near extirpation, there was little effort to monitor them because remnant populations were small, remote and in some cases unknown. (2012). Oyster mariculture formerly occurred in Elkhorn Slough, California, where no consumption by sea otters was reported (Estes and VanBlaricom, 1985), and currently occurs in the back portion of Morro Bay, California, although few sea otters use that area. In some cases, gear modifications are available that would reduce or exclude the potential for incidental take without appreciably affecting the catch of target species (Hatfield et al., 2011). Intraperitoneal satellite transmitters do not exist because of antenna limitations. Letter to FWS regarding the draft revised stock assessment report for the southern sea otter, Letter to FWSwith comments on the 2016 draft stock assessment report for the southern sea otter, Letter to FWS regarding an Application from California Department of Fish and Wildlife-Central Region to take southern sea otters incidental to construction activities in association with a tidal marsh restoration project in Elkhorn Slough, California, Letter to FWS regarding revised stock assessment report for the Southern sea otter. As the population expanded both north and south into habitat that was not observable from shore, aircraft were used for surveys. A., Kreuder, C., Paradies, D. M., Worcester, K. R., Jessup, D. A., et al. To find out more, see our cookie policy. The southern sea otter (Enhydra lutris nereis) population at San Nicolas Island, California, has been monitored annually since the translocation of 140 sea otters to the island was completed in 1990. % We pride ourselves on being a safe website for both teachers and students. doi: 10.1111/j.1523-1739.2012.01951.x, Coletti, H. A., Bodkin, J. L., Monson, D. H., Ballachey, B. E., and Dean, T. A. Plot of southern sea otter population trends along the mainland coast of California and at San Nicolas Island over the period 1990-2013. A., Wheeler, P. A., Dahlhoff, E., Sanford, E., and Strub, P. T. (1997). This partnership of federal, state and local institutions is seeking to increase our understanding of estuary habitat use by sea otters and to help inform the conservation and restoration of suitable habitat and water quality conditions at Elkhorn Slough. doi: 10.7589/0090-3558-39.3.495, Krkosek, M., Lauzon-Guay, J. S., and Lewis, M. A. 131, 526543. 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. The success of the translocations to Southeast Alaska, British Columbia, Canada, and Washington state helped mitigate declines in the Aleutian Islands. Plot of southern sea otter population trends along the mainland coast of California and at San Nicolas Island over the period 19902013. doi: 10.2307/1940749, Laidre, K. L., Estes, J. From 2017 to 2020, we measured a 22-percent per annum increase in population abundance (95-percent confidence interval =1134 percent) with 114 total individuals as of February 2020. translocation, Washington's sea otter population grew from a founding population estimated to be as few as 10 individuals (10-21%/yr; Jameson et al. Females move freely among these territories, but any female within a territory will be investigated for sexual receptivity. 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). Coast. However, not all unoccupied habitats are equivalent in terms of available resources such as food and shelter, and these differences can result in geographic barriers, discontinuous distributions, and variable population densities. Additional resources (found in trunk) that can be used to supplement reading articles: 1. Adult sea otters may eat as much as 9 kg (20 lbs.) Because of their well-documented effects on nearshore communities, broadly monitoring the littoral community along with sea otters provides information on the status of the ecosystem (Coletti et al., 2016). 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. endobj Harvest of sea otters in the United States is strictly limited to coastal Alaska Natives who can take sea otters for subsistence and for creating and selling authentic native handicrafts. 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). Alaska. Research is needed to quantify these benefits accurately and, where possible, tailor projections to locally affected communities so that they can be included properly in management decisions and economic forecasting. doi: 10.1371/journal.pone.0150547. A. '3 i]']&lExZ BX"!p+aL6IAnU/DaFLU7 0N$0b/ vqfSs[3fBaISS%;v]I~_?^t.8rjGJ>q8hO]%wGx5DMM-1L/uJ9ttRaw}Z 2Jb K[&x6k >E^[m$1fRcV6q)Y4IDnqpzwhPreoRlY~YoAG.3\0L\HU"!hm(ekpjm LcXT4q. (2009). (2002). Given the contribution of translocations to the conservation of sea otters by increasing the total numbers of sea otters present today, increasing population connectivity, increasing genetic diversity, and restoring coastal marine ecosystems, we suggest additional translocations be considered to facilitate sea otters recolonization of their historical range. Mamm. Conserv. A., and VanBlaricom, G. R. (1985). J. Wildl. PLoS One 8:e65435. 8 0 obj These measures are essential because they are sensitive indicators of population and environmental change and provide insights into the mechanisms of change (e.g., distinguishing food resource limitation from the effects of physical disturbance, disease, or predation pressure). Kenyon, K. W. (1969). doi: 10.2307/2937159. A .gov website belongs to an official government organization in the United States. doi: 10.1034/j.1600-0706.2000.900304.x. J. Zool. Why have sea otters been compared to teddy bears? First, sea otters at many western Aleutian Islands now exist at extremely low densities with only a few scattered individuals along exposed outer coastal habitats (e.g., one otter was observed in the Ogliuga/Skagul island complex in 2015 skiff survey; USFWS). Sea otters (Enhydra lutris) have been managed under international law longer (starting in 1911) than most marine mammal species (Figure 1). They found that a 50% reduction in the poaching of northern abalone was necessary to reach a short-term recovery goal of halting further declines in northern abalone density in the presence of sea otters. Popul. Biol. In coordination with the California Department of Fish and Game and other institutions, ongoing surveys and research continues to inform the southern sea otter recovery plan for the U.S. (1986a). Sea otters play a small role in mitigating global . Transmission of toxoplasma: clues from the study of sea otters as sentinels of Toxoplasma gondii flow into the marine environment. 45, 322375. /SA true Biol. This abundant population lasted until the early 1700s when the hunting of otters for their pelts began to popularize. (2001). D. Consequently, the frequency of large scale surveys in areas such as Southeast Alaska and the Aleutian Islands declined to decadal intervals. doi: 10.1016/j.dsr2.2017.04.008. 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. Beyond monitoring to detect trends or changes in sea otter abundance, we need to identify underlying causes of change, a decidedly more difficult task when approached after the change has occurred, but facilitated by incorporating likely mechanisms in monitoring design (see Question 3). J. Exp. The Commission also consults periodically with the FWS and marine mammal facilities to resolve questions about the placement of non-releasable otters from this population. It inhabits coastal waters from the Kuril Islands to the Aleutian Islands southward to the coast of California. To accomplish this, we have forged partnerships with scientific collaborators from the Federal, State and private sector, to produce high-quality scientific information on the role of various stressors in limiting sea otter abundance, and to ensure this information's relevance and application to current conservation problems. . Their short legs, webbed toes, and muscular tails aid in swimming, and they can close their ears and noses when diving down to forage for food. This created a situation where two independent census methods generated counts with variable and un-quantified detection probabilities. Measurements of species composition, size distribution and population densities in these various habitats allow us to look at trends over time. Population demographics and genetic diversity in remnant and translocated populations of sea otters. I am seeking a position where I . Potential designations could be based on both demography and habitat characteristics that currently allow sea otter persistence in some locations (see Questions 5 and 7), and could consider rates of genetic exchange between subpopulations, with the goal of maintaining or even improving the genetic health and heterozygosity of subpopulations (see Question 5). They do this to keep them from drifting away from the group while they rest/sleep floating on their backs. Course Hero member to access this document, Lia_Rudisill_-_1_extracted_Homeostasis_Population_Graphs_CC.pdf, Copy of Population Trends - Group Collaboration Form.pdf, 459F3086-450C-4285-BF3B-B97159FE769F.jpeg, B3D9BE94-7A76-4810-9325-F6E745985E3B.jpeg, Sam Barlow High School BIOLOGY Honors Bio, Sunrise Mountain High School PRE-AP BIOLOGY H 12259, South Pasadena Senior High SCIENCE 101 PG. (2018). Geoduck clam (Panopea abrupta) demographics and mortality rates in the presence of sea otters (Enhydra lutris) and commercial harvesting. Among these territories, but the nearshore ecosystems they occupy was not from! Populations along the mainland coast of California and at San Nicolas Island over period. Pride ourselves on being a safe website for both teachers and students genetic. Populations of sea otters serve as sentinels of Toxoplasma: clues from the while... 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