Sea Otters In Southeast Alaska
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Sea Otters In Southeast Alaska
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Author : Wendel W. Raymond
language : en
Publisher:
Release Date : 2020
Sea Otters In Southeast Alaska written by Wendel W. Raymond and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with Food chains (Ecology) categories.
The recovery of sea otters (Enhydra lutris) to Southeast Alaska is a conservation success story, but their increasing population raises questions about sea otter population dynamics and the ecological role of this top-level predator. In Chapter 1, we addressed these questions by investigating patterns and population effects of subsistence sea otter harvest. Subsistence harvest reduced populations at a small scale, with potential to slow or stop population growth, but across Southeast Alaska the population continues to grow, even with an average 3% subsistence harvest rate. In Chapters 2 and 3 we investigated the ecological role of sea otters in seagrass (Zostera marina) communities. When we tested for generality in a sea otter - seagrass trophic cascade across a large spatial scale in Southeast Alaska, we found a positive relationship between sea otters and seagrass. However, we found no evidence of a relationship between crabs and epifauna, suggesting that the ecological mechanisms in Southeast Alaska may differ from other regions. Our comparison of carbon and nitrogen stable isotopes (SI) to assess the role of sea otters on trophic structure and energetic pathways of seagrass beds found little effect of sea otters in overall community trophic niche space, suggesting similar carbon sources and food chain length in seagrass meadows regardless of sea otters. Conversely, the FA profiles of diverse consumer suggest variation in dietary sources with and without sea otters. This result suggests that the trophic cascade may not be the only or primary energetic pathway in Southeast Alaska seagrass communities. In all, our studies have revealed that sea otters in Southeast Alaska are linked to both people and a common Southeast Alaska nearshore habitat, seagrass. These results describe the varied interactions of a recovering top predator and highlight a need to consider these diverse interactions in resource management, conservation, and ecological research.
Survey Of Transplanted Sea Otter Populations In Southeast Alaska April 30 May 16 1975
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Author : Karl Burton Schneider
language : en
Publisher:
Release Date : 1975
Survey Of Transplanted Sea Otter Populations In Southeast Alaska April 30 May 16 1975 written by Karl Burton Schneider and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1975 with Mammal surveys categories.
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.
Resource Competition Space Use And Forage Ecology Of Sea Otters Enhydra Lutris In Southern Southeast Alaska
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Author : Zachary N. Hoyt
language : en
Publisher:
Release Date : 2015
Resource Competition Space Use And Forage Ecology Of Sea Otters Enhydra Lutris In Southern Southeast Alaska written by Zachary N. Hoyt and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2015 with Sea otter categories.
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.
Southeast Alaska S Rocky Shores
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Author : Rita M. O'Clair
language : en
Publisher:
Release Date : 1998
Southeast Alaska S Rocky Shores written by Rita M. O'Clair and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1998 with Natural history categories.
Final Environmental Impact Statement For Translocation Of Southern Sea Otters Technical Support Documents
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Author :
language : en
Publisher:
Release Date : 1987
Final Environmental Impact Statement For Translocation Of Southern Sea Otters Technical Support Documents written by and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 1987 with Animal introduction categories.
Sea Otter Conservation
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Author : Shawn Larson
language : en
Publisher: Academic Press
Release Date : 2014-12-23
Sea Otter Conservation written by Shawn Larson and has been published by Academic Press this book supported file pdf, txt, epub, kindle and other format this book has been release on 2014-12-23 with Nature categories.
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
Sea Otter Diet Composition With Respect To Recolonization Life History And Season In Southern Southeast Alaska
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Author : Nicole L. LaRoche
language : en
Publisher:
Release Date : 2020
Sea Otter Diet Composition With Respect To Recolonization Life History And Season In Southern Southeast Alaska written by Nicole L. LaRoche and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2020 with Sea otter categories.
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.
Return Of The Sea Otter
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Author : Todd McLeish
language : en
Publisher: Sasquatch Books
Release Date : 2018-03-20
Return Of The Sea Otter written by Todd McLeish and has been published by Sasquatch Books this book supported file pdf, txt, epub, kindle and other format this book has been release on 2018-03-20 with Nature categories.
"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.
Addressing A Complex Resource Conflict
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Author : Sonia Natalie Ibarra
language : en
Publisher:
Release Date : 2021
Addressing A Complex Resource Conflict written by Sonia Natalie Ibarra and has been published by this book supported file pdf, txt, epub, kindle and other format this book has been release on 2021 with Alaska Natives categories.
Complex resource conflicts may benefit from the inclusion of social-ecological systems approaches that recognize the complex linkages between humans and their environment. Competition for shared shellfish resources by sea otters and humans in Southeast Alaska has caused food security concerns, cultural and economic losses, and uncertainty about the future of various fisheries, including rural subsistence-based fisheries. In rural Alaska Native communities, access to subsistence resources are critical to maintaining a way of life, with deeply rooted knowledge systems that are tied to the land, water, and natural resources. This dissertation documents Indigenous and local knowledge of Alaska Native customary and traditional food experts, sea otter hunters, and elders (hereafter harvest experts) to understand empirical observation and interpretations of restoring balance with sea otters. This work took place within the traditional territories of the Tlingit and Haida people of Southeast Alaska in four rural communities, Kake, Klawock, Craig, and Hydaburg. With Tribal leaders and harvest experts, my collaborators and I used a participatory framework that became a formal partnership to co-develop study goals, objectives, and methodology. Through a multiple evidence-based approach, I co-conducted semidirected and site visit interviews, structured questionnaires, mapping exercises, and participant observation in all four communities, and intertidal bivalve (shellfish) surveys in Hydaburg and Kake. Qualitative and quantitative approaches revealed local and Indigenous knowledge about sea otters caused changes to subsistence shellfish resources and harvesting patterns that included declines in availability and spatial extent of shellfish harvests, and shifts in shellfish harvest hotspots. Community adaptive strategies to observed shellfish declines include shifting harvest locations away from sea otter presence. Community management recommendations about restoring balance with sea otters include increasing sea otter hunting locally using spatially explicit techniques. Financial subsidies for sea otter hunters, creating local tanneries, legal changes to the Marine Mammal Protection Act, and market creation and development for sea otter handicrafts were noted as solutions to barriers of local implementation to management recommendations. Commercial and charter fisheries are other factors that have contributed to shellfish declines. Butter clam (Saxidomus gigantea) size and density declined with increased distance to community and increased sea otter activity near Hydaburg, demonstrating the influence of sea otters and human harvests on bivalve population dynamics. Application of these results about Indigenous knowledge, management, and governance systems to sea otter management in Alaska could create a more inclusive, equitable and community-driven management approach.
The Southern Sea Otter
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Author : Ernie Holyer
language : en
Publisher: Steck-Vaughn
Release Date : 1975
The Southern Sea Otter written by Ernie Holyer and has been published by Steck-Vaughn this book supported file pdf, txt, epub, kindle and other format this book has been release on 1975 with Juvenile Nonfiction categories.
An introduction to the habits and behavior of the southern sea otter, an endangered species.