Download or read book Studies of Southeastern Alaska Sea Otter Populations written by Kenneth W. Pitcher and published by . This book was released on 1989 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Otter Population and Transplant Studies in Alaska 1959 written by Karl W. Kenyon and published by . This book was released on 1960 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alaska Sea Otter Research Workshop written by Daniela Maldini and published by . This book was released on 2004 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Otter Conservation written by Shawn Larson and published by Academic Press. This book was released on 2014-12-23 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea otters are good indicators of ocean health. In addition, they are a keystone species, offering a stabilizing effect on ecosystem, controlling sea urchin populations that would otherwise inflict damage to kelp forest ecosystems. The kelp forest ecosystem is crucial for marine organisms and contains coastal erosion. With the concerns about the imperiled status of sea otter populations in California, Aleutian Archipelago and coastal areas of Russia and Japan, the last several years have shown growth of interest culturally and politically in the status and preservation of sea otter populations. Sea Otter Conservation brings together the vast knowledge of well-respected leaders in the field, offering insight into the more than 100 years of conservation and research that have resulted in recovery from near extinction. This publication assesses the issues influencing prospects for continued conservation and recovery of the sea otter populations and provides insight into how to handle future global changes. - Covers scientific, cultural, economic and political components of sea otter conservation - Provides guidance on how to manage threats to the sea otter populations in the face of future global changes - Highlights the effects that interactions of coastal animals have with the marine ecosystem
Download or read book The Community Ecology of Sea Otters written by Glenn R. VanBlaricom and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: The impetus for this volume comes from two sources. The first is scientific: by virtue of a preference for certain large benthic invertebrates as food, sea otters have interesting and significant effects on the structure and dynamics of nearshore communities in the North Pacific. The second is political: be cause of the precarious status of the sea otter population in coastal California, the U.S. Fish and Wildlife Service (USFWS) announced, in June 1984, a proposal to establish a new population of sea otters at San Nicolas Island, off southern California. The proposal is based on the premise that risks of catastrophic losses of sea otters, due to large oil spills, are greatly reduced by distributing the population among two geographically separate locations. The federal laws of the U.S. require that USFWS publish an Environmental Impact Statement (ElS) regarding the proposed translocation of sea otters to San Nicolas Island. The EIS is intended to be an assessment of likely bio logical, social, and economic effects of the proposal. In final form, the EIS has an important role in the decision of federal management authority (in this case, the Secretary of the Interior of the U.S.) to accept or reject the proposal.
Download or read book Resource Competition Space Use and Forage Ecology of Sea Otters Enhydra Lutris in Southern Southeast Alaska written by Zachary N. Hoyt and published by . This book was released on 2015 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growing sea otter population in southern Southeast Alaska is impacting commercial shellfish, through foraging and expanding in range and abundance except where hunted for subsistence. Sea otters and their prey have coexisted in the North Pacific Ocean for approximately 750,000 years, but due to exploitation of sea otters from the 1770s until 1911, the species became extinct over much of its range, including southern Southeast Alaska. Subsequently, invertebrate species flourished and were commercially targeted in the late 1900s. Sea otters were relocated (n = 106) to southern Southeast Alaska in 1968. In this dissertation, I evaluated this marine mammal-fisheries conflict through multiple approaches. In Chapter 1, I analyzed geoduck clam and red sea urchin abundance surveys (1994-2012) and catch and effort data from commercial Dungeness crab fisheries (1969-2010) to identify interactions between sea otters and commercial shellfish. In Chapter 2, I collected geo-locations from 30 instrumented sea otters (2011-2014) to identify space use and range expansion. In Chapter 3, I collected sea otter abundance and distribution data from fixed wing aircraft (2010-2014) and observational forage data from sea otters (2010-2013) to determine contemporary population growth and consumption of commercially important shellfish by sea otters. The sea otter population in southern Southeast Alaska has grown from 106 to an estimated 13,139 individuals between 1968 and 2011 with an annual growth rate of 12% and expansion of its range by 117 km2 y-1. Results from a before-after, control-impact analysis indicate that sea otters are rapidly impacting red sea urchin and significantly reducing geoduck clam densities. Further, breakpoints predicted from regression models of Dungeness crab catch are correlated with known sea otter colonization timing. Forty-six percent of the population level diet of sea otters represented commercially important prey. Sea otters targeted commercially important species, specifically red sea urchins and Dungeness crab, when first colonizing an area, after which the diet of sea otters became more diverse as colonization durations increased. Using habitat models based on a bivariate normal probability distribution function, environmental covariates and subsistence hunting pressure on sea otters, I determined that sea otter range expansion was limited by subsistence hunting. Further, female and non-territorial males segregated based on habitat and likely prey preferences. I conclude that sea otter populations will likely continue to grow, and that current shellfisheries cannot coexist with sea otters under existing management. Further, conservation and management of sea otter populations, whether to increase the distribution through translocation efforts or reduce the distribution to avoid human conflicts, could benefit from insights gained from spatially explicit modeling at the landscape level.
Download or read book Sea Otters written by Richard Ravalli and published by U of Nebraska Press. This book was released on 2021-06 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: An examination of sea otters in a Pacific World context and an exploration of how this iconic sea mammal once defined the world’s largest oceanscape.
Download or read book Southern Sea Otter Recovery Plan written by and published by . This book was released on 1982 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Survey of Transplanted Sea Otter Populations in Southeast Alaska April 30 May 16 1975 written by Karl Burton Schneider and published by . This book was released on 1975 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Between 1965 and 1971, some 403 sea otters were transplated to six sites in Southeast Alaska. A survey was conducted jointly by Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service between April 30 and May 16, 1975, to determine the distribution and abundance of sea otters there. Table 1 summarizes significant sea otter sightings between 1965 and 1975.
Download or read book Status and Trends of Sea Otter Populations in Southeast Alaska 1969 2003 written by George G. Esslinger and published by . This book was released on 2009 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diet Composition and Fate of Contaminants in Subsistence Harvested Northern Sea Otters Enhydra Lutris Kenyoni from Icy Strait Alaska written by Kristin Lynn Brown and published by . This book was released on 2020 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Northern sea otters (Enhydra lutris kenyoni) in Southeast Alaska have experienced a significant population increase since their successful reintroduction to the area after previous near extirpation owing to historic fur trading. The purpose of this study was to examine sea otter diet and metals contamination in an area of Southeast Alaska with the most robust increases in sea otter numbers, Glacier Bay/Icy Strait, with the intent of gathering baseline data for a healthy population of sea otters and as a reflection of the local coastal environmental health of the area. This research was a collaborative effort with Alaska Native subsistence hunters and the Alaska Department of Environmental Conservation. In Chapter 1, sea otter stomachs (n=25) were obtained in April 2015 and April 2016 from Alaska Native subsistence hunters in Icy Strait, Alaska. There were no differences in sea otter diet between years. Bivalves dominated the sea otter diet. Northern horsemussels (Modiolus modiolus) made up the greatest proportion of the diet (0.46 ± 0.48). Fat gaper clams (Tresus capax) and northern horsemussels were found in the highest proportion of stomachs (0.64 and 0.60, respectively). There was not an apparent trend between sea otter age and the minimum number of total prey items, stomach contents mass, or mean frequency of occurrence of the top four prey species. Sea otters from this study are likely to be dietary generalists throughout their lives. In Chapter 2, brain, gonad, kidney, and liver tissues, as well as stomach contents were analyzed for arsenic, cadmium, copper, lead, total mercury, and selenium for the 2015-harvested sea otters that were also referenced in Chapter 1 (n=14). In general, arsenic and lead had the highest concentrations in stomach contents, cadmium and selenium were highest in the kidneys, and copper and total mercury were highest in the livers. While brains and gonads had the lowest metals concentrations of any tissue, the metal with the greatest concentration within the brain was copper, and within the gonads was selenium. Concentrations of arsenic, cadmium, total mercury, and lead demonstrated a relationship with sea otter length. In general, all the mean metals concentrations for these sea otters were below published effects threshold values for marine mammals. Only total mercury demonstrated biomagnification from the stomach contents (i.e., the prey) to all higher-level tissues. Selenium health benefit values were positive in all sea otter tissue types analyzed in the present study, indicating that concentrations of selenium had an overall health benefit in protecting those tissues against mercury toxicity. Evaluating how contaminants concentrate and get distributed in tissues of top trophic levels provides an indication for potential exposure to humans and demonstrates how these keystone species act as indicators of local coastal ecosystem health. The results of studies on dietary exposure and metals contamination in top trophic level consumers such as sea otters can be used in monitoring the health of sea otter populations and the local environment that they inhabit.
Download or read book Return of the Sea Otter written by Todd McLeish and published by Sasquatch Books. This book was released on 2018-03-20 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Captivating. . . . a full portrait of this adorable and ecologically important animal." —Publishers Weekly A science journalist travels the Pacific Coast in search of sea otters in this entertaining and inspiring book on the importance and history of this charismatic endangered species Sea otters—the adorable, furry marine mammals often seen floating on their backs holding hands—reveal the health of the coastal ecosystem along the Pacific Ocean. Once hunted for their prized fur in the 18th and 19th centuries, these animals nearly went extinct. Only now, nearly a century after hunting ceased, are populations showing stable growth in some places. Sea otters are a keystone species in coastal areas, feeding on sea urchins, clams, crab, and other crustaceans. When they are present, kelp beds are thick and healthy, providing homes for an array of sea life. When otters disappear, sea urchins take over, and the kelp disappears along with all the creatures that live in the beds. Now, thanks to their protected status, sea otters are making a comeback in California, Washington, and Alaska. In this hopeful book, science writer Todd McLeish embarks on an epic journey along the Pacific Coast—traveling from California to Alaska—to track the status, health, habits, personality, and viability of sea otters, and reveals how conservationists brought them back from the brink of extinction.
Download or read book Final Environmental Impact Statement for Translocation of Southern Sea Otters Technical support documents written by and published by . This book was released on 1987 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ethology and Behavioral Ecology of Sea Otters and Polar Bears written by Randall W. Davis and published by Springer Nature. This book was released on 2021-07-03 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea otters and polar bears are carnivorous marine mammals that still resemble their terrestrial ancestors. Compared with Cetacea (whales and dolphins), Sirenia (dugongs and manatees), and Pinnipedia (seals, sea lions, and walrus), they are less adapted for an aquatic life and the most recently evolved among marine mammals. Sea otters are amphibious but seldom come ashore, and polar bears primarily occur on sea ice or along the shore. When at sea, both species spend most of their time swimming at the surface or making short, shallow dives when foraging or pursuing prey. Indeed, polar bears rarely pursue seals in water. Nevertheless, polar bears are powerful swimmers and will stalk seals from the water. As with many other large carnivores, they are solitary hunters. Although sea otters are gregarious and form aggregations at sea called rafts, they are primarily asocial. Except during mating, the principal interaction among sea otters occurs between a female and offspring during the six-month dependency period. In large carnivores (e.g., wolves and lions) that feed on ungulates, sociality and cooperation are favored because of the need to capture large prey and defend carcasses. Polar bears, which are the largest terrestrial carnivore, are solitary hunters of seals and are neither gregarious nor social. Males and females briefly associate during courtship and mating. During this time, males aggressively compete for females. At other times, males generally avoid each other except for aggregations of males that form while summering on land, and females with cubs avoid males, which are known for infanticide. As with sea otters, the interaction of polar bears outside of mating occurs between a female and her offspring during the 2-3 year dependency period. This interaction is critically important when altricial cubs are born in the winter den. This book provides new insight into the ethology and behavioral ecology of sea otters and polar bears. Each chapter reviews the discoveries of previous studies and integrates recent research using new techniques and technology. The authors also address historic and current anthropogenic challenges for their survival as climate change alters entire marine ecosystems.
Download or read book Tool Use in Animals written by Crickette M. Sanz and published by Cambridge University Press. This book was released on 2013-03-07 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last decade has witnessed remarkable discoveries and advances in our understanding of the tool using behaviour of animals. Wild populations of capuchin monkeys have been observed to crack open nuts with stone tools, similar to the skills of chimpanzees and humans. Corvids have been observed to use and make tools that rival in complexity the behaviours exhibited by the great apes. Excavations of the nut cracking sites of chimpanzees have been dated to around 4-5 thousand years ago. Tool Use in Animals collates these and many more contributions by leading scholars in psychology, biology and anthropology, along with supplementary online materials, into a comprehensive assessment of the cognitive abilities and environmental forces shaping these behaviours in taxa as distantly related as primates and corvids.
Download or read book Life History of Southeastern Alaska Land Otters and Marten written by Loyal Johnson and published by . This book was released on 1981 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sea Otter Diet Composition with Respect to Recolonization Life History and Season in Southern Southeast Alaska written by Nicole L. LaRoche and published by . This book was released on 2020 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Until translocation efforts in the 1960s, sea otters (Enhydra lutris) were absent from Southeast Alaska due to extirpation by the fur trade in the 18th and 19th centuries. About 400 sea otters were reintroduced to six Southeast Alaska locations, including two sites near Prince of Wales Island in southern Southeast Alaska. The most recent US Fish and Wildlife Service population count, completed in 2012, estimated that about 25,000 sea otters inhabited Southeast Alaska. Sea otters will reduce invertebrate prey biomass when recolonizing an area. By quantifying sea otter diets and caloric intake according to recolonization patterns, we can better understand the ecosystem impacts of sea otter population increase and range expansion. The goal of this study was to quantify changes in seasonal diet composition and assess the energetic quality of sea otter prey in southern Southeast Alaska. I made visual foraging observations of 3,385 sea otter dives around Prince of Wales Island (POW) to determine diet composition during the spring and summer months. I then collected vibrissae from 45 sea otters obtained from subsistence hunters to assess year-round sea otter diets using stable isotopes. I collected sea otter prey items throughout POW in three seasons (May 2018, August 2018, and February 2019) to measure energy, lipid and protein content, and delta13C (carbon) and delta15N (nitrogen) values. Sea otter diets mainly consisted of clams, as quantified both from visual observations and stable isotope analysis. However, there was more variation in the diet estimates from stable isotope analysis. Stable isotope analysis revealed variation among individual diets of sea otters and individuality in diet within the POW region of sea otters. Sea otters seasonally increased consumption of some prey when the prey was highest in lipid and overall caloric content. Sea otters switched prey types when the prey was more energetically valuable. The results of this study will aid in future management of shellfisheries, subsistence hunting, and implementing co-management of a protected species by providing quantitative diet composition data for stakeholders. This work is a part of a large-scale project examining how the recovery of sea otters structures nearshore marine ecosystems, provides ecosystem services, and affects community sustainability.
