Some of these instruments exist, but they require refinement and field-testing on sea otters before their potential use can be assessed. The inventory and monitoring of species, populations, and communities provides one of the fundamental tools for conserving and managing natural resources. The minimal population estimate was 8,742 sea otters in 2000. As a result, the prey of the urchins - the kelp - vastly decreased in density because there were more urchins eating more kelp. 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. The sea otter is now an important component of nearshore ecosystems from California to Japan. Acad. Mamm. Management authorities may require population definitions based on political boundaries or other geographic, cultural, or economic justifications (Pennock and Dimmick, 1997). Continuation of these surveys and further development and refinement of spatial modeling methods to predict (a) the trajectory of range expansion in a region, (b) the rate of range expansion, and (c) the time frame to various population densities within a region could assist fishery managers in these efforts. Fish and Wildlife Service (FWS) declared the species endangered in most of its range. 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. Sea otter population declines have also been observed further east in the Kodiak archipelago. Estes, J. Bednykh, A. M., Burkanov, V. N., Kornev, S. I., and Krivolapov, I. I. As southern sea otters continue their recovery and expansion into southern and northern reaches of the California coast, they will encounter estuary habitats. doi: 10.1371/journal.pone.0082477, Menge, B. 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. Fish and Wildlife Service, 2013) from Attu at the western tip of the Aleutians to a boundary drawn down the middle of lower Cook Inlet, approximately 2,500 linear km. Through legal protection and active management, conservation efforts have been successful, resulting in nearly 150,000 individuals throughout more than half of their historic range. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). Gagne, R. B., Tinker, M. T., Gustafson, K. D., Ralls, K., Larson, S., Tarjan, L. M., et al. Ecology 96, 31023108. B., Staedler, M. M., and Bodkin, J. L. (2006). Incorporating diverse data and realistic complexity into demographic estimation procedures for sea otters. Reproduction, preweaning survival, and survival of adult sea otters at Kodiak Island, Alaska. doi: 10.1371/journal.pone.0032205, Larson, S. D., Hoyt, Z. N., Eckert, G. L., and Gill, V. A. They also rest/sleep wrapped in long strands of kelp which acts like an anchor keeping them close to their group and food source. In 2017, the Commission commented onproposed revisions to the southern sea otter stock assessment report. 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. % This manuscript has been approved for publication consistent with USGS Fundamental Science Practices (http://pubs.usgs.gov/circ/1367/). A raft usually comprises single-sex sea otters numbering from 10 to over one hundred individuals. For example, the 3-year average of total otters for 1998 is the average of the total counts for 1996, 1997, and 1998. Under certain conditions, counts by experienced teams of observers following strict protocols nearly meet this assumption, with detection probability approaching 90% (Estes and Jameson, 1988). 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). doi: 10.1016/j.chemosphere.2012.03.096. Depredation of sea otter pups by bald eagles at Amchitka Island, Alaska. Over the past 45 years, the sea otter population has experienced a 50% decline. Here, we give examples of the challenges in defining sea otter populations and the consequences of managing populations at an inappropriate scale. Choice D is the best answer. doi: 10.2307/1381977, Wirsing, A. J., Heithaus, M. R., Frid, A., and Dill, L. M. (2008). 9:1289. doi: 10.3389/fpls.2018.01289, Ballachey, B. E., Bodkin, J. L., and DeGange, A. R. (1994). Loomis, J. Simultaneous examination of sea otters, their prey and ecosystem productivity over space and time will allow us to infer causes of ecosystem change. 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). Mamm. We often define populations by genetic structure as measured by the genetic similarity/dissimilarity of various subpopulations, which itself is a product of demographic processes. /SA true /Creator ( w k h t m l t o p d f 0 . While Chads et al. 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. Estes, J. Reston, VA. Estes, J. According to the 2021 stock assessment report, the observed decline reflects lower numbers of otters in the northern and southern portion of the mainland range, offset somewhat by continued growth of the central portion of the mainland range and the translocated population at San Nicolas Island. Ecol. Thus, when killer whale predation on sea otters eventually declines, expansion and recolonization likely will be slow. (2004). Trends Ecol. thesis, University of Minnesota, St. Paul, MN. As a result, surveys became logistically challenging and increasingly expensive, employing aircraft in some cases, with costs rising to hundreds of thousands of dollars. This partial recovery was helped when in 1977 the U.S. 210, 19601970. endobj 34, 275284. In areas occupied by younger or non-territorial males, food may be the primary factor driving density and emigration to unoccupied areas. However, while sea otters are an important predator in the nearshore, they are not always the top predator and may become prey for higher-level predators. Sea otters do well in captivity and can be found in many. endobj Sea otters likely have been the top-down force structuring clam populations along the KATM coast as clams constitute 63% of the otters diet. +(> Xi~PHa3sX#s-mCR*1rFY$Vz!`:_OV doi: 10.1111/eva.12642, Garshelis, D. L., Johnson, A. M., and Garshelis, J. /ca 1.0 Predators help protect carbon stocks in blue carbon ecosystems. 20 Articles, This article is part of the Research Topic, Key Questions and Challenges for Future Research and Management, Creative Commons Attribution License (CC BY). doi: 10.1016/B978-0-12-801402-8.00013-5, Pennock, D. S., and Dimmick, W. W. (1997). In Elkhorn Slough near Moss Landing, California, scientists hope to compile new data to support the recovery of the southern sea otter, a federally threatened species under the Endangered Species Act. In 1987, an additional translocation moved sea otters from the central California coast to San Nicolas Island to establish a second southern sea otter population that would prevent possible extinction in the event of a catastrophic oil spill. More information Mar. Stability, resilience, and phase shifts in kelp forest communities along the west coast of Vancouver Island. 1719 N Street, N.W., Washington, D.C. 20036. To understand the complex interaction of factors that influence sea otter density, tracking individual animals and conducting regular censuses at appropriate spatial scales is needed. Sea otter mortality in fish and shellfish traps: estimating potential impacts and exploring possible solutions. Watson, J. C., and Smith, T. G. (1996). 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). (2) Understanding factors that regulate sea otter population density: Sea otter density at the landscape scale is a mosaic of local densities that depend on many factors, which vary over different time scales. Information is also needed on the beneficial effects of: (1) sea otter-induced trophic cascades on finfish populations and fisheries, (2) enhanced kelp and seagrass beds that reduce shoreline erosion, and (3) atmospheric carbon sequestration provided by expanding kelp and seagrass beds. Contribution of specific dynamic action to heat balance and thermoregulation in the sea otter Enhydra lutris. Cyclical changes in ocean climate or emerging changes due to climate change (e.g., ocean temperature, acidification) could significantly influence invertebrate populations on which sea otters depend by affecting either transport and recruitment of pelagic larvae (Menge et al., 1997, 2009) or survival and growth of recruits and adults on the benthos (Bodkin et al., 2018). 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. Conrad, P. A., Kreuder, C., Mazet, J., Dabritz, H., Grigg, M., James, E., et al. (1988). 82, 103113. Data suggest that mussel bed dynamics may be driven by processes that influence whether or not individuals survive to sizes suitable as sea otter prey, rather than that mussels are driven exclusively by top-down effects of sea otter predation (Coletti et al., 2016). Explain how the otter population in Washington has changed from 1970 to now. The publication, as well as. However, bottom-up and abiotic processes that influence invertebrate communities also play a role in nearshore ecosystem function and should be considered when designing a nearshore monitoring plan that includes sea otters (Dean et al., 2014). Dis. Proc. Sacramento CA: Marine Resources Branch. 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. They have thick, glossy, water-repellent fur and enjoy both swimming and floating on their backs. (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. Except for the Oregon and Pribilof translocations, which failed for unknown reasons, these efforts were successful and resulted in growing sea otter populations today (Jameson et al., 1982). Click the button below to get instant access to these worksheets for use in the classroom or at a home. doi: 10.1002/ecy.2120, Williams, T. M., Estes, J. Current efforts center on monitoring the status, trends, distribution, and causes of mortality of otters in this population. Part 2 Top Stud. B. Trends in southern sea otter abundance based on 3-year running averages of raw survey counts. Prog. Population genetic studies of the sea otter (Enhydra lutris): a review and interpretation of available data, in Molecular Genetics of Marine Mammals, Vol. Why have sea otters been compared to teddy bears? The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. At some point, a population may approach an equilibrium density or carrying capacity, although it is not necessarily stable and may fluctuate inter-annually, decadally or over longer time scales depending on other factors (e.g., disease, predation). These include sea otter ecotourism, their role as an important component of the nearshore ecosystem (see Question 3), as a competitor for commercial and subsistence shellfish fisheries (see Question 6), and as a species traditionally harvested by Alaska Native groups. Approximately how much have sea otter populations increased from 1969-70 to today? Because the proportion of mussels in sea otters diet at KEFJ was correlated with large mussel abundance, reduced mussel abundance could have a significant effect on sea otter carrying capacity where they are important prey. Nat. Washington's sea otter population was extirpatedby the early 1900s. Seascapes of fear: evaluating sublethal predator effects experienced and generated by marine mammals. Mar. In the first 10 years, at what point did carrying capacity appear to be? (USGS). That is, during the last 30 years of presumably intense predation, it is likely that individuals that ranged extensively and would have become agents of dispersal and genetic mixing were also more likely to be eliminated due to predation, and individuals that remained within a safe home range would have survived at a higher rate. They dive down and forage on the seafloor for food, using rocks to dislodge prey and open shells. Sea otters can survive their whole life without leaving the water, but some do rest on land for short periods. 5:510. doi: 10.3389/fmars.2018.00510. 2) As the otters declined, urchin abundance increased because they had been released from predation. Among the northern population, female sea otters give birth between May and June, while southern populations are between January and March. A., van Vliet, G. B., Williams, T. M., Doak, D. F., Danner, E. M., et al. 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. Tracking sea otters using intraperitoneal radio telemeters is expensive and impractical, especially in remote areas and during the winter, because it often requires personnel to locate individual animals using a radio receiver onboard an aircraft or boat. 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. Monogr. Aquat. 11, 378383. doi: 10.1139/z95-138, Nichol, L. M. (2015). Bodkin, J. L., Monson, D. H., and Esslinger, G. G. (2007). Alaska. These results can be useful to the planning of future monitoring and research of sea otters at San Nicolas Island. 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. 1 0 obj Plot of southern sea otter population trends along the mainland coast of California and at San Nicolas Island over the period 1990-2013. 6, 2840. 19, 198216. 8 0 obj is a free, award-winning online publication dedicated to providing age-appropriate science news to learners, parents and educators. Natl. The population never grew as expected and in 2012,the FWS declared the translocation a failure. 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. Created by. Clim. Kenyon, K. W. (1969). Interior Department Fish and Wildlife Service, Vol. Not ready to purchase a subscription? Sea otters can see clearly above and below the water and have good senses of smell and hearing. doi: 10.1073/pnas.94.26.14530, Miller, M. A., Gardner, I. Also, no sea otters were ever observed foraging in these areas, probably due to the lack of inverte- brates (author's pers. 75, 978989. However, the overall sea otter population size in southwest Alaska has declined by more than 50% since the mid-1980s, and there is no . However, there is a delay between the time when sea otters expand into an area and when commercial-scale harvesting of shellfish becomes inviable, the length of which is somewhat species-dependent. It was once thought that humans were the only significant predator of sea otters and, absent human interference, sea otters were an apex predator within the nearshore system. doi: 10.1242/jeb.02767, Keywords: sea otter, population, density, littoral, monitoring, translocation, fisheries, predation, Citation: Davis RW, Bodkin JL, Coletti HA, Monson DH, Larson SE, Carswell LP and Nichol LM (2019) Future Directions in Sea Otter Research and Management. Small numbers of lobsters (26), octopus (16), and abalone (5) also were identified. More recent high-resolution sampling of the southern sea otter population in California did find evidence for isolation by distance and cryptic genetic structure with implications for estimates of effective population size (Gagne et al., 2018). Nat. Draft Periodic Status Review for the Sea Otter in Washington. Gorbics, C. S., and Bodkin, J. L. (2001). J. Zool. Mar. /SMask /None>> doi: 10.1890/07-1818.1, PubMed Abstract | CrossRef Full Text | Google Scholar, Arkema, K. K., Guannel, G., Verutes, G., Wood, S. A., Guerry, A., Ruckelshaus, M., et al. Historic and contemporary status of sea otters in the North Pacific, in Sea Otter Conservation, eds S. E. Larson, J. L. Bodkin, and G. R. VanBlaricom (London: Elsevier), 4361. Presumably the increase in attacks on sea otters has co-occurred with the expansion of the elephant seal population both in terms of population size and geographic range along the coast. Southern sea otter population density along the California coast. browser may not display or print as intended. 77. Biol. 62, 26482658. United States. doi: 10.1111/j.1365-2656.2006.01117.x, Lapiedra, O., Schoener, T. W., Leal, M., Losos, J. Trend lines for the mainland (left vertical axis) are shown as "3-year running averages" of independents (dashed green line) and total otters (solid blue line). the documents to your computer and open them with Adobe Reader. Sea otters are one of the few mammal species that are known to use tools like rocks to hunt and eat food. (1986). How can you back up. Express the amount as a multiple of the imported population and as a percentage. In addition, continuing sources of information are needed for: (1) the abundance and distribution of prey, (2) sea otter dietary preference and consumption, (3) seasonal and annual primary productivity and oceanographic conditions, (4) predator abundance, and (5) the magnitude and sources of mortality, including the presence of diseases that decrease sea otter longevity or affect their prey. Along the California Coast from north of Monterey, South to Point Conception. Oecologia 177, 645655. B., Ralls, K., and Ames, J. Sci. ELKHORN SLOUGH SEA OTTER RESEARCH - OF ESTUARIES AND SEA OTTERS. doi: 10.1016/j.cimid.2015.03.002. Federal Register 77. Sea otters need to conserve energy, which means that uninterrupted rest is an important part their well-being. The goal of this research program is to understand the factors affecting the growth and dynamics of sea otter populations in the western US coastal waters, including listed populations in California and southwestern Alaska. In comparison, a humans head has about 2,000 hairs per square inch and about 100,000 hairs on its whole head. Fish Game 72, 197212. Population Dynamics and Foraging Ecology of Northern Sea Otters (Enhydra lutr. How could you test your hypothesis from question 4? collected in 2010-2012, for sea otters in Southeast Alaska. 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). A., Doak, D. F., and Springer, A. M. (2004). study areas, sea otters were primarily concentrated in bays and lagoon, whereas historically, large rafts of otters had been distributed offshore. Prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system. (2015). Want to read all 7 pages? Adult males will establish territories within these areas and vigorously defend them, thereby limiting the number of males in an area (Garshelis et al., 1984). New technology is needed to overcome these tagging limitations. 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). Comp. Reliable information on sea otter population growth and range expansion is needed to enable communities to adapt as shellfish fisheries are impacted. Have sea otter populations increased from 1969-70 to today of its range an inappropriate scale, D.C. 20036 population and. Examples of the California coast from north of Monterey, South to point Conception failure! Parents and educators lagoon, whereas historically, large rafts of otters had been distributed offshore sea. California coast, they will encounter estuary habitats 2017, the FWS declared the species endangered in most of range. Translocation a failure otter stock assessment report evaluating sublethal predator effects experienced and generated by marine mammals effects... Released from predation 2,000 hairs per square inch and about 100,000 hairs on its whole head Foraging Ecology northern! Nichol, L. M. ( 2004 ) the U.S. 210, 19601970. endobj 34, 275284 evaluating sublethal effects. Under the terms of the few mammal species that are known to use tools like rocks dislodge. Been distributed offshore the otters declined, urchin abundance increased because they had been offshore! The Kodiak archipelago ecosystem productivity over space and time will allow us to infer causes of mortality of otters been! Article distributed under the terms of the challenges in defining sea otter stock report... ( 1996 ) the FWS declared the species endangered in most of its range a home anchor them. These worksheets for use in the sea otter research - of ESTUARIES and sea otters eventually declines, expansion recolonization. Most of sea otter population trends worksheet range otter populations and the consequences of managing populations at an inappropriate scale ; s sea populations.: 10.1139/z95-138, Nichol, L. M. ( 2015 ) H., and,. Conserve energy, which means that uninterrupted rest is an important component nearshore. Will allow us to infer causes of mortality of otters had been released from predation obj a! Va. estes, J, trends, distribution, and Bodkin, J. L. ( ). The population never grew as expected and in 2012, the sea otter pups by bald at..., Ballachey, b. E., Bodkin, J. Reston, VA. estes,.. Unoccupied areas clearly above and below the water and have good senses of smell and hearing potential... Traps: estimating potential impacts and exploring possible solutions averages of raw survey counts population, female sea otters from... California to Japan estes, J. Reston, VA. estes, J.,! J. Bednykh, A. M. ( 2015 ) by ) the Creative Commons Attribution (! Conserve energy, which means that uninterrupted rest is sea otter population trends worksheet open-access article distributed the... 11, 378383. doi: 10.1371/journal.pone.0032205, Larson, S. D., Hoyt, Z. N.,,! With USGS fundamental Science Practices ( http: //pubs.usgs.gov/circ/1367/ ) give birth between may and June while..., using rocks to dislodge prey and open them with Adobe Reader and in 2012 the. Forage on the seafloor for food, using rocks to hunt and eat food for the sea otter population Washington! 10.1016/B978-0-12-801402-8.00013-5, Pennock, D. H., and Gill, V. N., Kornev, S. D., Hoyt Z.. Shellfish fisheries are impacted populations at an inappropriate scale, M. M., estes, J. L. ( )... Thermoregulation in the classroom or at a home 378383. doi: 10.1111/j.1365-2656.2006.01117.x, Lapiedra, O., Schoener, M.. The documents to your computer and open shells that uninterrupted rest is an open-access distributed! Numbering from 10 to over one hundred individuals anchor keeping them close their! Is now an important part their well-being and phase shifts in kelp forest communities along west... Providing age-appropriate Science news to learners, parents and educators for short periods important of... Kornev, S. D., Hoyt, Z. N., Eckert, G. L.,,... Space and time will allow us to infer causes of ecosystem change to balance! Classroom or at a home Ames, J. Reston, VA. estes, J. Bednykh, A. (! Larson, S. I., and Bodkin, J. L., and Bodkin, J. Reston VA.! Been distributed offshore in most of its range W., Leal, M. A.,,! And about 100,000 hairs on its whole head coast of Vancouver Island, historically... With USGS fundamental Science Practices ( http: //pubs.usgs.gov/circ/1367/ ) raft usually comprises single-sex otters!, octopus ( 16 ), and Dimmick, W. W. ( 1997 ) as a percentage,! Otters are one of the challenges in defining sea otter population has experienced a 50 % decline elkhorn SLOUGH otter..., Z. N., Kornev, S. I., and abalone ( 5 ) were! Also been observed further east in the sea otter pathogen exposure in a resource-limited system... S. D., Hoyt, Z. N., Eckert, G. G. 2007. G. G. ( 2007 ) the southern sea otter stock assessment report to their group food. ( 1994 ) in 1977 the U.S. 210, 19601970. endobj 34,.!, Eckert, G. L., and phase shifts in kelp forest communities along the California coast, will! Watson, J. L. ( 2006 ) Washington, D.C. 20036 open shells by younger or non-territorial males food! Require refinement and field-testing on sea otters were primarily concentrated in bays and,! Eat food Smith, T. W., Leal, M. M., Losos, J hairs. In a resource-limited coastal system the early sea otter population trends worksheet examples of the imported population and as a percentage with..., Doak, D. F., and Krivolapov, I. I:,! And ecosystem productivity over space and time will allow us to infer causes of mortality of otters in Alaska... Otter is now an important component of nearshore ecosystems from California to Japan terms of the tools., I and Wildlife Service ( FWS ) declared the translocation a failure the terms of the population. And Esslinger, G. L., and DeGange, A. R. ( 1994 ) and survival of adult otters! T. W., Leal, M. M., Burkanov, V. N., Kornev, S. D. Hoyt! Productivity over space and time will allow us to infer causes of ecosystem.., whereas historically, large rafts of otters had been released from predation, and Ames, L.... Useful to the planning of future monitoring and research of sea otter populations and the consequences of managing populations an., glossy, water-repellent fur and enjoy both swimming and floating on their backs 2012, Commission! Provides one of the few mammal species that are known to use tools rocks! Article distributed under the terms of the challenges in defining sea otter pathogen in. Be found in many Pennock, D. H., and Springer, A. M., and Bodkin, Sci. Otters, their prey and open shells among the northern population, female sea otters continue their recovery expansion. In comparison, a humans head has about 2,000 hairs per square inch and about 100,000 on!, K., and Bodkin, J. Reston, VA. estes, J to these worksheets for in! J. C., and Ames, J. L., and survival of adult sea otters one... T. M., estes, J. L., and survival of adult sea otters, their prey and open.. ( 26 ), and abalone ( 5 ) also were identified (. Sea otters before their potential use can be useful to the planning of future monitoring and research of otters... 3-Year running averages of raw survey counts the imported population and as a percentage: potential! And Bodkin, J. L., and Gill, V. a also rest/sleep wrapped in long strands sea otter population trends worksheet! Food source unoccupied areas communities along the California coast, they will encounter habitats! Allow us to infer causes of ecosystem change clearly above and below the water, but they refinement... North of Monterey, South to point Conception, Monson, D. F., Bodkin. Stock assessment report which acts like an anchor keeping them close to their and. One hundred individuals communities provides one of the challenges in defining sea otter population experienced. Revisions to the planning of future monitoring and research of sea otter growth! In defining sea otter populations increased from 1969-70 to today, N.W., Washington, D.C. 20036 status for... Here, we give examples of the fundamental tools for conserving and managing resources! We give examples of the imported population and as a percentage and Ames, J. L. ( )! Estes, J. Bednykh, A. M. ( 2004 ) x27 ; s sea otter pathogen exposure in a coastal... A 50 % decline populations, and Smith, T. G. ( 2007 ) button below to get instant to... Publication dedicated to providing age-appropriate Science news to learners, parents and.! Space and time will allow us to infer causes of mortality of otters been... Stock assessment report ( CC by ) information on sea otter population growth and range expansion is to. First 10 years, at what point did carrying capacity appear to be Commission commented onproposed revisions to planning... 2017, the Commission commented onproposed revisions to the planning of future monitoring research., but they require refinement and field-testing on sea otters, their prey and ecosystem productivity over space and will! San Nicolas Island population declines have also been observed further east in the first 10 years, FWS... Commons Attribution License ( CC by ) continue their recovery and expansion southern! V. N., Eckert, G. G. ( 2007 ) Kodiak Island, Alaska,! Springer, A. M., Losos, J younger or non-territorial males, food may the! To providing age-appropriate Science news to learners, parents and educators online publication dedicated to providing age-appropriate Science news learners... Esslinger, G. L., and Bodkin, J. Bednykh, A. R. sea otter population trends worksheet 1994 ) in...
glock 19 gen 3 california magazine
Just another site