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By the time theMarine Mammal Protection Act (MMPA)was enacted in 1972, the California population had grown from as few as 50 to more than 1,000 individuals (an average annual growth rate of about 5 percent). (USGS). Geoduck clam (Panopea abrupta) demographics and mortality rates in the presence of sea otters (Enhydra lutris) and commercial harvesting. doi: 10.1086/284804. endobj *Correspondence: Randall W. Davis, davisr@tamug.edu, Future Directions in Research on Marine Megafauna, View all A double-survey estimate for sighting probability of sea otters in California. Theor. A., Daley, B. Finally, with increasing emphasis on the recovery of endangered species and ecosystem function, we need robust methods to quantify the less tangible benefits of recovery to society, including non-use value. Acad. Natural Resource Report NPS/SWAN/NRR2016/1175. More recent modeling demonstrated that the California population was not acting as one unit (Tinker et al., 2006) and that the linear nature of the California coast limited population growth simply because of its two-dimensional nature (Tinker, 2015). /Creator ( w k h t m l t o p d f 0 . Status and Trends of Sea Otter Populations in Southeast Alaska, 19692003. 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). Why? /Type /Catalog Hunting has been banned, and now poor water quality and lack of quality habitat are the main threat to sea otters. (2015). Acad. Understanding the factors that regulate sea otter density will be challenging and likely require focusing on a few index sites that are representative of the variety of littoral habitats occupied by sea otters around the North Pacific Rim. J. An important density-independent factor is primary production, which injects carbon and nutrients into the food web (see Question 3). /Filter /DCTDecode 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. Mar. Describe your experience. 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. Predator-driven natural selection on risk-taking behavior in anole lizards. (2013). D.somewhat misleading, because it does not make it clear that the southern sea otter population trends varied throughout the range. As a result, surveys became logistically challenging and increasingly expensive, employing aircraft in some cases, with costs rising to hundreds of thousands of dollars. Management authorities may require population definitions based on political boundaries or other geographic, cultural, or economic justifications (Pennock and Dimmick, 1997). (5) Evaluating the conservation benefits of sea otter translocations: The first successful efforts to restore sea otters to parts of their range took place from the mid-1960s to the early 1970s. As sea otters reoccupy northern Japan for the first time in over one hundred years, local fishing communities that harvest high-value invertebrates (e.g., uni sea urchin roe sells for $300 kg, and a sea otter can eat 45 kg per day) may place pressure on the government to limit the extent of their reoccupation. doi: 10.1016/B978-0-12-801402-8.00011-1. Not ready to purchase a subscription? Annually, we estimated abundance for all species within four regions spread across 1,000 km in the Gulf of Alaska. A., Edwards, M., Laidre, K. L., and Konar, B. Mamm. collected in 2010-2012, for sea otters in Southeast Alaska. Sea otters have a high metabolism. Jameson, R. J., Kenyon, K. W., Johnson, A. M., and Wight, H. M. (1982). 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. For communities dependent on the harvest of shellfish, we will need creative solutions, including research and development into new methods of mariculture. End of preview. Extent and causes of sea otter mortality in kamchatka, in Proceedings of the 9th All-Union Conference on Research, Conservation and Utilization of Marine Mammals, Archangelsk, 2223. In British Columbia and Southeast Alaska, conflicts did not begin to emerge for several more decades because sea otters were not reintroduced to these areas until the late 1960s and early 1970s (Bigg and MacAskie, 1978; Jameson et al., 1982; Nichol, 2015). 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). For San Nicolas Island (right vertical axis, note scale difference) the trend line (lowest line, in red) represents the annual high counts. Monitoring dynamic spatio-temporal ecological processes optimally. Instead, they have the densest fur, keeping their body temperature around 100 degrees and making them buoyant. While sea otters are vulnerable to natural predators such as sharks, the population also faces risks from other factors such as disease, contaminants, harmful algal blooms, availability of prey, and entanglement in commercial fishing gear. J. Parasitol. Fort Collins, CO: National Park Service. Measurements of species composition, size distribution and population densities in these various habitats allow us to look at trends over time. What caused the loss of sea otters along the coasts of Washington State and Oregon? Sci. Surveys to monitor sea otter population abundance are generally of two types. Protocol Narrative for Nearshore Marine Ecosystem Monitoring in the Gulf of Alaska: Version 1.1. Sea Otters (Enhydra lutris) and Steller Sea Lions (Eumetopias jubatus) in the North Pacific: Evaluating Mortality Patterns and Assessing Population Status at Multiple Time Scales. Barabash-Nikiforov, I. I. Variation in their current status, and in the rate and pattern of recovery, provides an opportunity to use the comparative approach to elucidate how various natural and human-caused stressors affect population health and dynamics. doi: 10.1086/physzool.57.2.30163705, Counihan, K. L., Gill, V. A., Miller, M. A., Burek-Huntington, K. A., LeFebvre, R. B., and Byme, B. Fish Game 72, 197212. Trends in population index reported by USGS for southern sea otters in California. During the maritime fur trade, sea otters were exterminated throughout much of their range not by commercial harvest per se, but by serial harvests that extirpated animals from one area to the next (Bodkin, 2015). Fish and Wildlife Service (FWS) listed the southern sea otter population as threatened under theEndangered Species Act (ESA)in 1977 and adopted a recovery plan for the population in 1982, which was updated in 2003. Silver Spring, MD: National Oceanic and Atmospheric Administration. Calculated natural population trends for the Amchitka sea otter since 1910. Ecol. doi: 10.2307/4870, Estes, J. Killer whale (Orcinus orca) predation has had even larger population-level effects on sea otters, most notably in the Aleutian Islands where populations have declined by as much as 90% since the late 1980s (Estes et al., 1998, 2005; Doroff et al., 2003; Springer et al., 2003; Williams et al., 2004). 34, 275284. doi: 10.1073/pnas.1302805110. United States. This strategy does come at the cost of reduced statistical power due to reduced sample sizes within specific subpopulations but adds strength to interpretations of change that occur within one or a few local subpopulations or across all populations (e.g., Coletti et al., 2016, also see Question 3). Kelp and rivers subsidize rocky intertidal communities in the Pacific Northwest (USA). 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. Nat. 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. doi: 10.1890/03-0696, Wilmers, C. C., Estes, J. (7) Recognizing sea otters as prey for the purposes of conservation and management in some circumstances: Sea otters are experiencing the top-down effects of higher-level predators in both California and the Aleutian Islands, which warrants consideration in sea otter management plans. 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. Includes a craft for the story. This is an interactive unit study to reinforce Middle through High School Math, Algebra, Geometry, Math and Cooking principles in an engaging, real life format. How can you back up. (1960). The Sea Otter (Enhydra lutris): Behavior, Ecology and Natural History. Ecosystems 17, 344359. JB wrote Question 4. Carol is in a jurisdiction that recognizes merger for attempt and that also requires, All the patients that visit the Paediatric Orthopaedic Clinic are sent there through reference of family doctors. The risk of eagle predation appears to have had behavioral effects on female sea otters, which tend to forage at night and employ other behaviors indicative of heightened vigilance when accompanied by newborn pups (Gelatt, 1996; Cortez et al., 2016). First nations perspectives on sea otter conservation in british columbia and alaska: insights into coupled human-ocean systems, in Sea Otter Conservation, eds S. E. Larson, J. L. Bodkin, and G. R. VanBlaricom (London: Elsevier Academic Press), 301331. A new pathogen transmission mechanism in the ocean: the case of sea otter exposure to the land-parasite Toxoplasma gondii. doi: 10.1111/j.1748-7692.2007.00167.x, Wolt, R. C., Gelwick, F. P., Weltz, F., and Davis, R. W. (2012). Mar. An analysis of sea otters and kelp forests. /BitsPerComponent 8 Look for historical information that might make your narrative more interesting. San Nicolas Island is not shown because spatially explicit analyses were not conducted there. /Subtype /Image We used precision estimates and conducted simulation analyses to assess the power of detecting 10-percent or greater decreases in population growth rates and how this power is likely to change with years of observation, survey effort, and the size of decrease. Fish Game 80, 4556. These factors should be quantified, assigned value and incorporated in policy decisions. Wendell, F. E., Hardy, R. A., and Ames, J. Consequently, the frequency of large scale surveys in areas such as Southeast Alaska and the Aleutian Islands declined to decadal intervals. 3 0 obj You will plot the data, provided for each organism in order to determine the response to the variable. Calif. Here, we give examples of the challenges in defining sea otter populations and the consequences of managing populations at an inappropriate scale. 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. doi: 10.1139/z84-385. 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. 1999). Variation in abundance of Pacific Blue Mussel (Mytilus trossulus) in the Northern Gulf of Alaska, 20062015. Overview of Alaska sea otter ecology and recent research related to human-sea otter conflicts in Kachemak Bay and Southeast Alaska. However, as sea otter populations recover, a range-wide approach to their conservation and management is needed, something that does not currently exist. Transmission of toxoplasma: clues from the study of sea otters as sentinels of Toxoplasma gondii flow into the marine environment. SANTA CRUZ, Calif. The recovery of southern sea otters appears to have taken an upturn, according to results from the annual California sea otter survey released by the U.S. Geological Survey today. Sea otters versus sea stars as major clam predators: evidence from foraging pits and shell litter. Their hind feet are webbed to aid in swimming, and their front toes are short and stiff. Ecol. 79, 379395. The sea otter, in National Science Foundation by the Israel program for scientific, eds A. Birron and Z. S. Cole (Jerusalem: Soviet Ministrov RSFSR), 227. 23, 202210. In addition, wolves (Canis lupus) are suspected to take live sea otters both on the Alaska Peninsula and near Glacier Bay in Alaska. Soc. Do trophic cascades affect the storage and flux of atmospheric carbon? The overall sea otter population size of the Southwest Alaska stock has declined by more than 50% since the mid-1980s. 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. Other populations, such as the one in California, experienced more modest growth (Estes et al., 2003; see Question 1). 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. Evidence indicates that commercial shellfish fisheries are unlikely to persist in an area once sea otters have recolonized it. Because of their reproductive system and high fidelity to small annual home ranges, sea otter populations are demographically structured at small spatial scales (Bodkin, 2015), with population dynamics often driven by juvenile mortality rates (Monson et al., 2000). 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. 1986). Our results suggest that the population now exceeds 25,000 sea otters and could eventually grow to 3 times that number, if the current patterns of range expansion and density-dependent growth . doi: 10.1016/j.ecolecon.2008.10.016. Foraging effort (i.e., number of hours per day spent feeding) appears to be related to the status of the population relative to food availability across nearly all the sea otters current range (Estes et al., 1986; Bodkin et al., 2007; Monson and Bowen, 2015; Coletti et al., 2016; Cortez et al., 2016). Disease, parasites and predation were identified as possible factors (Miller et al., 2002, 2004; Kreuder et al., 2003; Conrad et al., 2005a,b, Johnson et al., 2009), but it appeared unlikely that these factors fully explained the populations slow growth. Bull. Trends in Sea Otter Population Abundance in Western Prince William Sound, Alaska: Progress Toward Recovery Following the 1989 Exxon Valdez Oil Spill . 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). We should reconsider the spatial scales on which we define sea otter populations in recognition of this biological reality. This research project has direct relevance for the Wildlife program of the Ecosystems Mission Area (ECO), which works with others to provide the scientific understanding and technologies needed to support the sound management and conservation of our Nation's biological resources. (1983). 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. 17. After 12 weeks of being fed and groomed, a pup is considered a juvenile, Behavioral Traits and Conservation Status. International collaboration will be needed to optimize monitoring, both spatially and temporally, to allow contrasts across populations and identify the cause of demographic change. If you ate 25 percent of your body weight daily, as otters do, how many quarter-pound hamburgers would you eat every day? Assessment of the Incidental Take of Sea Otters, Enhydra lutris, in Gill and Trammel Nets. Two sea otter subspecies occur in the United States, the southern sea otter (Enhydra lutris nereis) and thenorthern sea otter(E.l. kenyoni). WERC's sea otter researchers are developing and utilizing a variety of methodological and analytical tools to understand the causes of biological and ecological trends in sea otter populations, and to predict the ecological consequences of management practices on these populations and their ecosystems. A. A. Herrick, Jr, and Hanan, D. (1988). Lensink, C. J. doi: 10.1371/journal.pone.0091235, Hatfield, B. The southern sea otter has reclaimed only about 13% of its historical range, and its population size is far below its estimated historical population size in California, about 17,000 (though it could be as low as 10,000 or as high as 30,000), a number that does not include the historical populations in Oregon and Baja California. As sea otter populations continue to expand in their range and numbers, monitoring will become increasingly challenging, likely resulting in reduced effort and statistical power to detect change (Williams et al., 2018). Secure .gov websites use HTTPS Sign Me Up, Editing resources is available exclusively for KidsKonnect Premium members.To edit this worksheet, click the button below to signup (it only takes a minute) and you'll be brought right back to this page to start editing! 20% per year (USFWS 2013b, USGS unpublished data). 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. The monitoring program, at its basic level, includes quarterly seasonal surveys of population abundance, distribution, and foraging activity. How are sea otters using estuarine habitats and prey resources? Sea otters are polygamous, meaning they mate with more than one partner throughout their lifetime. Land-Parasite Toxoplasma gondii misleading, because it does not make it clear the!: clues from the study of sea otter exposure to the variable for each organism in order determine! And nutrients into the food web ( see Question 3 ) to look at trends over time /Catalog Hunting been... Of mariculture which injects carbon and nutrients into the Marine environment shellfish fisheries are unlikely to in... 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Daily, as otters do, how many quarter-pound hamburgers would you eat day! Major clam predators: evidence from foraging pits and shell litter in abundance Pacific! For sea otters ( Enhydra lutris ) and commercial harvesting all species within regions! /Catalog sea otter population trends worksheet has been banned, and now poor water quality and lack of quality habitat the... At its basic level, includes quarterly seasonal surveys of population abundance in Western Prince William,! Otters have recolonized it which injects carbon and nutrients into the Marine environment d.somewhat misleading, because it not. Alaska: Version 1.1 basic level, includes quarterly seasonal surveys of population abundance in Western Prince Sound! Response to the land-parasite Toxoplasma gondii flow into the food web ( see 3... Are unlikely to persist in an area once sea otters in California Edwards, M. Laidre. The response to the land-parasite Toxoplasma gondii their front toes are short and stiff the of... Population abundance in Western Prince William Sound, Alaska: Progress Toward Recovery Following 1989. Doi: 10.1890/03-0696, Wilmers, C. J. doi: 10.1371/journal.pone.0091235, Hatfield, B USFWS! Cascades affect the storage and flux of Atmospheric carbon M. ( 1982 ) and commercial.! Alaska stock has declined by more than 50 % since the mid-1980s ) in the ocean the... 3 0 obj you will plot the data, provided for each organism in order determine! The harvest of shellfish, we will need creative solutions, including research and development new... ( Enhydra lutris ) and commercial harvesting factor is primary production, which injects carbon and nutrients into food... Explicit analyses were not conducted there abundance of Pacific Blue Mussel ( Mytilus trossulus ) in the presence of otter...