(2015). Sci. Many of these challenges will require new tools including the next generation geolocation tag technology that will allow assessments of long-range movements, dispersal and gene flow in various populations. doi: 10.1890/10-0262.1. A .gov website belongs to an official government organization in the United States. Dis. Our goals were to provide a comprehensive picture of population trends and abundance estimates at dierent spatial scales and to estimate equilibrium densities of sea otter populations in Southeast Alaska, and how they vary over space, as a tool to help resource managers anticipate Hughes, B. doi: 10.1016/j.jas.2011.12.006, Tallis, H. (2009). Their food is usually filter feeders Why go to all the effort to save sea otters? This manuscript includes a review of past research and does not include any new data or metadata releases. Sci. They are a keystone species, so if they die, so will much of their habitat. doi: 10.1111/mms.12261, Traiger, S. B., Konar, B., Doroff, A., and McCaslin, L. (2016). Intuitively this explanation makes sense, but it took decades for biologists to fully realize how a population functioning at small spatial scales in conjunction with shoreline complexity could explain the relatively slow growth of the California population, which for decades was a source of concern for sea otter researchers and conservation organizations. (2013). Intraperitoneal satellite transmitters do not exist because of antenna limitations. Scribner, K. T., Bodkin, J., Ballachey, B., Fain, S. R., Cronin, M. A., and Sanchez, M. (1997). 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). 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. Imagine that you are on a hunting ship long ago when there were many sea otters. A., and Kenyon, K. W. (1978). Shallow littoral sites within the four regions have been randomly selected and are sampled annually. 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. Efforts to help communities reliant on commercial, recreational, or subsistence shellfish harvesting will require meaningful dialog to predict effects and find solutions. In 1969 and 1970, a total of 59 sea otters were captured at Amchitka Island, Alaska, and released near Point Grenville and LaPush off Washington's Olympic Peninsula coast (Jameson et al. Trends in southern sea otter abundance based on 3-year running averages of raw survey counts. 3, eds A. E. Dizon, S. J. Chivers, and W. F. Perrin (Lawrence, KS: Special publication of the Society of Marine Mammalogy), 197208. Herrick, Jr, and Hanan, D. (1988). Ecology 90, 546555. In addition to their fishery-related impacts, sea otters may come into conflict with recovery efforts for other threatened or endangered species that are part of their natural prey base. This manuscript has been approved for publication consistent with USGS Fundamental Science Practices (http://pubs.usgs.gov/circ/1367/). Open Fish Sci. Research is needed to quantify the strength and persistence of sea otters effects on these and other species targeted by finfish fisheries, to identify the relevant timescale over which changes may be anticipated after sea otters recolonize and area, and to link these changes to fisheries production. (PDF). Mamm. They dive down and forage on the seafloor for food, using rocks to dislodge prey and open shells. /SM 0.02 Bodkin, J. L., Ballachey, B. E., Cronin, M. A., and Scribner, K. T. (1999). Between 1911, when hunting was prohibited, and 1972, when the MMPA was passed, these otters recolonized more than 200 miles (370 kilometers) of the California coast. EXAMPLE: the sea otters, kelp, urchins, and sharks living together in La Push Students also viewed Status of translocated sea otters at San Nicolas Island, California. Doroff, A. M., Estes, J. In the first 10 years, at what point did carrying capacity appear to be? Fish and Wildlife Service initiated a sea otter monitoring and research plan to determine the effects of military readiness activities on the growth or decline of the southern sea otter population at San Nicolas Island. 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. The GIS shapefile Range extent of southern sea otters 2019.shp is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris nereis) in mainland California, based on data collected during the spring 2019 range-wide census. 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. 1982, 1986; Bodkin et al. Genetic diversity and population parameters of sea otters, Enhydra lutris, before fur trade extirpation from 17411911. Science 360, 10171020. What is the trend between 15-30 years in the sea otter population? doi: 10.1139/z84-385. Most notable are the nearshore areas: (1) between Northern Japan and throughout the east coast of Sakhalin Island, Russia (1,000 km); (2) between the southern portion of Southeast Alaska and parts of British Columbia (400 km); (3) between central Washington State (the current southern range limit of the northern sea otter) and midway between Monterey Bay and San Francisco Bay, CA, United States (the current northern range limit of the southern sea otter; 1,500 km); and (4) south of Santa Barbara, CA, United States (the current southern range limit of the southern sea otter) and central Baja California (800 km) (Larson and Bodkin, 2015). Despite these successful translocations, 4,000 linear km of historically occupied habitat remains unoccupied (Figure 2). doi: 10.1371/journal.pntd.0002852, Watson, J., and Estes, J. Garshelis, D. L., and Siniff, D. B. Central California gill net effort and bycatch of sensitive species, 1990-1998, in Seabird Bycatch: Trends, Roadblocks, and Solutions, eds E. F. Melvin and J. K. Parrish (Fairbanks, AK: University of Alaska Sea Grant), 141160. 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). A., et al. When otters disappear, the urchin population explodes and quickly "deforests" the . doi: 10.1038/srep33912. Much has been learned about the drivers and effects of sea otter population growth and range expansion because of systematic and regular population surveys, tagging and tracking programs, and diet studies throughout their range. The overall sea otter population size of the Southwest Alaska stock has declined by more than 50% since the mid-1980s. Although the FWS declared the translocation a failure, it is quite possible that otter numbers at San Nicolas will continue to grow. Sea otters were once widespread across coastal waters in the Northern Pacific Ocean, from Baja California to Alaska, all the way to rocky reefs in Russia and Japan. The spring census provides the primary basis for gauging population trends by State and Federal management agencies. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the United States Government. The San Nicolas population remained small (20 animals) for decades, and the translocation program was administratively deemed a failure in the early 2000s (Federal Register 77, 2012; p. 75266). Ph.D. thesis, University of Alaska, Fairbanks. 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). In the following, we recommend avenues for future research on sea otters in relation to fisheries, threatened or endangered species, climate change, ecotourism, and non-market valuation to inform the analyses that guide environmental policy and management. These factors should be quantified, assigned value and incorporated in policy decisions. New technology is needed to overcome these tagging limitations. doi: 10.2307/1376352. Nat. Interannual changes in productivity can influence the abundance and growth of sea otter prey, which will have an important bottom-up effect on the carrying capacity of an area. doi: 10.3354/meps08138, Tarjan, L. M., and Tinker, M. T. (2016). Why do you find those questions interesting? Why? While these two examples focus on the recolonization by sea otters of areas without fisheries conflicts, existing long-term monitoring programs, such as GWA, should guide the development of research questions that focus on the effects of recolonization on commercially viable prey species. doi: 10.1016/j.mambio.2012.03.002, Yeates, L. C., Williams, T. M., and Fink, T. L. (2007). Proc. Mussel Bed Sampling: Standard Operating Procedure, v. 1.2, Southwest Alaska Network. Sci. 5 0 obj Sci. What kinds of other animals share the sea otters habitat? for the first time. the southern sea otter Who helps control the sea urchin population? Washington, DC: U.S. This partial recovery was helped when in 1977 the U.S. In 2017, the U.S. Navy and the U.S. The lack of any evidence of consumption of sea otter carcasses suggests that they are not consumed by sharks but are the victims of exploratory bites that nonetheless result in injury and death (Tinker et al., 2016). Describe your experience. In addition, the risk of oil spills remains an ongoing concern. Evol. FWS, U.S. Geological Survey, and their partners are expected to continue to conduct annual abundance surveys and respond to strandings, including conducting necropsies to identify the causes of death for retrieved carcasses. The USGS range-wide sea otter census has been undertaken each year since 1982, using consistent methodology involving both ground . Rockfish Recruitment and Trophic Dynamics on the West Coast of Vancouver Island: Fishing, Ocean Climate, and Sea Otters. q"4\$j$\F,p1*'H`q $UU` FH'[TzVe6sQ=^)f}Ak The geographic range of sea otters has fluctuated over the last 300 years. 35, 11551168. The effect of sea otters on shellfisheries in British Columbia, in Invertebrate Working Papers, eds C. M. Hand and B. J. Waddell (Ottawa: Fisheries and Oceans Canada), 262303. doi: 10.1111/j.1748-7692.2003.tb01102.x, Estes, J. 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. Reston, VA. Estes, J. 77. Other populations, such as the one in California, experienced more modest growth (Estes et al., 2003; see Question 1). For example, management could focus on protecting habitats that provide refugia from predation by killer whales and sharks. Continuing sea otter population declines in the Aleutian archipelago. Sea otter pups are susceptible to predation by bald eagles (Haliaeetus leucocephalus) in areas where they co-occur (Sherrod et al., 1975; Anthony et al., 2008). (2004). The earliest censuses of sea otters were conducted by the Russian Coast Guard in the Commander Islands from 1924 to 1930 (Barabash-Nikiforov, 1947). Sign Me Up. Current (purple) and historic (yellow) sea otter range. The data collected by Dr. Estes are shown. For example, in central California, where a higher sea otter density is positively associated with higher black abalone density, sea otter predation may have served to reduce poaching impacts by driving black abalone into deep crevice habitat where they were safe from sea otters and poachers (Raimondi et al., 2015). 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). What percentage of your weight would those burgers represent. Range expansion predictions based on dispersal distance or reaction-diffusion models had mixed success but generally did not provide definitive biological context for the mechanisms driving population expansion (Lubina and Levin, 1988; Krkosek et al., 2007). 20% per year (USFWS 2013b, USGS unpublished data). Sea Otter Population Trends Direction:Complete the Sea Otter Population Graph (Graph #3) and answer the questions below. Since the mid-1980s, the sea otter population in southwest Alaska has declined by an estimated 56-68% . To reduce the risk of a large oil spill contacting otters throughout all or much of the species range, the FWS, in the late 1980s, attempted to establish a separate population at San Nicolas Island through a translocation of otters from the parent range. Despite the translocation having been declared a failure, the population on San Nicolas Island continues to increase. The severity and geographic extent of this decline raise several conservation concerns. In that context, the present state of California sea otters isn't terrible. A. Coastal habitats shield people and property from sea-level rise and storms. As sea otters reoccupy an area, populations of epibenthic prey such as sea urchins, crabs and abalone generally decline first followed by infaunal species such as large bivalves, depending on habitat (Kvitek and Oliver, 1992; Kvitek et al., 1993). (2016). Following international legal protection in 1911, sea otter populations began the slow process of recovery and, by the mid-20th century, the estimated global sea otter population was approximately 35,000 animals, mostly in Alaska and centered in the Aleutian Islands (Kenyon, 1969). Sea otters do well in captivity and can be found in many. History and status of translocated sea otter populations in North America. As a keystone predator, sea otters have also been found to exert strong effects on food web structure and dynamics, and their recovery to impaired ecosystems may have important implications for resiliency of nearshore marine ecosystems to emerging threats such as climate change and infectious diseases. The USGS range-wide sea otter census has been undertaken each year since 1982, using consistent methodology involving both ground-based and aerial-based counts. This created a situation where two independent census methods generated counts with variable and un-quantified detection probabilities. doi: 10.1016/j.ecolecon.2008.10.016. Monson, D. H. (2009). Sacramento CA: Marine Resources Branch. doi: 10.3106/1348-6160(2005)30[41:HASOSO]2.0.CO;2, Heithaus, M. R., and Dill, L. M. (2006). A new pathogen transmission mechanism in the ocean: the case of sea otter exposure to the land-parasite Toxoplasma gondii. Includes a craft for the story. The Coinciding with recent population growth, the sea otter distribution, which previously tended to concentrate on the west side, appears to have shifted toward an expansion of use in the north and especially greater seasonal use in the north and south during winter and spring. A., Underwood, K. E., and Karmann, M. J. Explain. The draft report identified the potential for sea otters to become trapped in gear used to catch crab, lobster, and finfish. 2 0 obj The threat to the southern sea otter posed by oil spills prompted . Considering (1) that the 2000 Coastal freshwater runoff is a risk factor for Toxoplasma gondii infection of southern sea otters (Enhydra lutris nereis). (Theresa Soley/KTOO) John Ryan lives in Hollis, on Prince of Wales Island. When you are finished take a picture of your graphs and submit them with the assignment. 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. Social organization of sea otters in prince william sound, Alaska. Change 5, 10381045. 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. Both perspectives recognize the important role sea otters play in structuring the shallow, littoral ecosystem, but the perspectives differ in time and space. Secure .gov websites use HTTPS Washington's sea otter population was extirpatedby the early 1900s. 560, 7386. 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. B. A Review of California Entangling Net Fisheries, 1981-1986. Because of their elevated resting metabolic rate and food consumption (25% of body weight per day, primarily benthic invertebrates; Costa and Kooyman, 1984; Yeates et al., 2007; Wolt et al., 2012), sea otters are widely recognized as susceptible to density-dependent competition for food (Kenyon, 1969; Estes, 2015). Mar. A., Chan, F., Nielsen, K. J., Lorenzo, E. D., and Lubchenco, J. KidsKonnect is a growing library of premium quality educational materials, printable worksheets and teaching resources for use in the classroom. 210, 19601970. doi: 10.1007/s10021-013-9715-7. Moreover, sea otters provide an excellent indicator species for nearshore coastal ecosystems, because the factors that affect individual health and survival of sea otters also affect other vertebrate species in these systems, including humans. Sea otters are one of the smallest marine mammals in the world, yet they are the largest member of the weasel family. 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. doi: 10.1371/journal.pone.0032205, Larson, S. D., Hoyt, Z. N., Eckert, G. L., and Gill, V. A. We will develop an integrative modeling approach that can be used to combine a broad range of data types including behavior, life history, demography, bio-medical, physiology, pathology, parasitology and epidemiology, in order to arrive at a process-based understanding of the factors affecting sea otter populations, and then use this model to provide resource managers with projections of population dynamics and viability under alternative management scenarios, and/or in response to anticipated environmental change. The second perspective focuses on the near-term impact of sea otters on large invertebrates (e.g., clams, crabs and urchins) that flourished in their absence and enabled economically and culturally important fisheries to thrive. 389, 8596. Historically, sea otters occurred in coastal waters throughout the rim of the North Pacific Ocean from northern Japan to Baja California, Mexico, with southern sea otters ranging from Oregon to Baja California. Ecol. Coast. The monitoring program, at its basic level, includes quarterly seasonal surveys of population abundance, distribution, and foraging activity. (2015). Along the west coast of North America, they remained absent from eastern Prince William Sound in Alaska to central California- a linear distance of approximately 4,000 km of nearshore habitat where they formerly existed.