sea otter population trends worksheet

(2011). Kelp and rivers subsidize rocky intertidal communities in the Pacific Northwest (USA). In areas occupied by younger or non-territorial males, food may be the primary factor driving density and emigration to unoccupied areas. An official website of the United States government. Mol. The population never grew as expected and in 2012,the FWS declared the translocation a failure. 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). 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 reference any of the content on this page on your own website, please use the code below to cite this page as the original source. The guard hairs can be brown to black to silver. 1 0 obj Southwest. Using molecular epidemiology to track Toxoplasma gondii from terrestrial carnivores to marine hosts: implications for public health and conservation. 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). After their near extirpation, remnant sea otter populations and those that resulted from reintroduction were below carrying capacity and experienced a period of logistic growth. Conrad, P. A., Miller, M. A., Kreuder, C., James, E. R., Mazet, J., Dabritz, H., et al. Bull. 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. To minimize the potential for disturbance and harm to sea otters, people sharing sea otter habitat should: Conrad, P. A., Kreuder, C., Mazet, J., Dabritz, H., Grigg, M., James, E., et al. Over the past 45 years, the sea otter population has experienced a 50% decline. Fort Collins, CO: National Park Service. A., Kreuder, C., Paradies, D. M., Worcester, K. R., Jessup, D. A., et al. Fish Game 80, 4556. 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. Ecol. Vocabulary worksheets. A. Manage. In 2017, the Commission commented onproposed revisions to the southern sea otter stock assessment report. He's seen the island's population of sea otters soar over the last handful of years . 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. doi: 10.1016/j.dsr2.2017.04.008. Sea otters have the thickest fur of any mammal/animal. Sci. Within that range, sea otters exist along the exposed coasts of many island groups, particularly in the western Aleutians, at extremely low densities (e.g., only one sea otter was sighted at the Ogliuga/Skagul Island group in the 2015 skiff survey; USFWS). An official website of the United States government. Fish and Wildlife Service. 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. 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). (2014). A., Estes, J. The severity and geographic extent of this decline raise several conservation concerns. Similar serial harvests are not likely to be repeated, but any management strategy that allows harvests of any kind should consider harvest levels within smaller geographic subunits. Oikos 90, 457468. Link will appear as Sea Otter Facts & Worksheets: https://kidskonnect.com - KidsKonnect, August 5, 2018. Mussel Bed Sampling: Standard Operating Procedure, v. 1.2, Southwest Alaska Network. The success of the translocations to Southeast Alaska, British Columbia, Canada, and Washington state helped mitigate declines in the Aleutian Islands. 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). 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). A raft usually comprises single-sex sea otters numbering from 10 to over one hundred individuals. From this perspective, the focus would be on predicting the effect of sea otter reoccupation on commercially valuable resources (see Question 6). doi: 10.1016/j.tpb.2007.01.008, Kvitek, R. G., Bowlby, C. E., and Staedler, M. (1993). 3, eds A. E. Dizon, S. J. Chivers, and W. F. Perrin (Lawrence, KS: Special publication of the Society of Marine Mammalogy), 197208. 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. B., Staedler, M. M., and Bodkin, J. L. (2006). Mamm. 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 monitoring program, at its basic level, includes quarterly seasonal surveys of population abundance, distribution, and foraging activity. Sci. Sea otters likely also benefit Pacific herring (Clupea pallasii) and salmonids (Oncorhynchus spp.) Factors that regulate female densities are not well known, but small annual home ranges are suggestive of behavioral mechanisms. Do trophic cascades affect the storage and flux of atmospheric carbon? Silver Spring, MD: National Oceanic and Atmospheric Administration. 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. A., Tinker, M. T., Johnson, A. Additional research is needed to establish the mechanisms controlling abalone density in the presence of sea otters and to guide management actions accordingly (Lee et al., 2016). Sea otters have a high metabolism. Why dont scientists kill sea urchins to help maintain the kelp population? This biologist uses microwave radiation to save endangered species, Chemists have unlocked the secrets of long-lasting Roman concrete, Native Amazonians make rich soils and ancient people may have too, Sea life may suffer as plastic bits alter metals in water, Heres how to increase clean energy without harming wildlife, The next astronauts to walk the moon will be more diverse than the last, A powerful laser can control the paths that lightning takes, Using Science News Explores in the Classroom. A. Sequential megafaunal collapse in the North Pacific Ocean: an ongoing legacy of industrial whaling? Monitoring efforts have varied in frequency and type across years. 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. Ecology 90, 546555. The sea otter population in Southeast Alaska has grown extensively since the translocation of just over 400 sea otters to 6 locations in the late 1960s. thesis, University of Minnesota, St. Paul, MN. Am. /SM 0.02 Experiment: Are fingerprint patterns inherited? Where sea otters persist, there is more complexity and productivity in the nearshore marine ecosystem. Washington's sea otter population was extirpatedby the early 1900s. Sci. 32, 309326. J. Trop. To find out more, see our, Download the Sea Otter Facts & Worksheets, Sea Otter Facts & Worksheets: https://kidskonnect.com, Resources created by teaching professionals. Does tiger shark predation risk influence foraging habitat use by bottlenose dolphins at multiple spatial scales? %PDF-1.7 Although sea otters are often referred to as an upper trophic level predator, they are not always at the apex. Nat. Sea otters regularly dig for infaunal prey (e.g., bivalves) in eelgrass meadows (), inadvertently breaking up rhizomes, creating pits (), and leaving bare patches where seeds may settle (Fig. /ca 1.0 When you are finished take a picture of your graphs and submit them with the assignment. Riedman, M. L., and Estes, J. Forney, K. A., Benson, S. R., and Cameron, G. A. 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). Natural history, ecology, and the conservation and management of sea otters, in Sea Otter Conservation, eds S. E. Larson, J. L. Bodkin, and G. R. VanBlaricom (London: Elsevier), 1941. The limited size of sea otters home ranges and differences in growth rates among areas indicate that their populations are demographically structured at spatial scales as small as several hundred km2 (Bodkin, 2015), but how do we distinguish one population from another? Females with pups will occupy areas that provide important resources such as food and protection from wind and waves. doi: 10.1890/1051-0761(2006)016[2293:IDDARC]2.0.CO;2, Tinker, M. T., and Hatfield, B. Current (purple) and historic (yellow) sea otter range. 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).

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