Sea otter foraging habits and effects on prey populations and communities in soft bottom environments; effects of foraging by sea otters on mussel dominated intertidal communities; kelp communities and sea otters; effects of sea otter foraging on subtidal reef communities off central California; fish populations in kelp forests without sea otters, effects of severe damage and destructive sea urchin grazing; effects of kelp forests on nearshore environments, biomass, detritus, and altered flow; sea otters and nearshore benthic communities.

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.

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

"Many of the findings in the book . . . are classics of ecology. . . . A rare and delightful insight into timely science."—Jane Lubchenco, Nature "Estes's refreshing narrative deftly weaves rigorous science with personal reflection to create an absorbing and introspective read that is equal parts memoir, ecological textbook, and motivational guidebook for young ecologists."—Science To newly minted biologist James Estes, the sea otters he was studying in the leafy kelp forests off the coast of Alaska appeared to have an unbalanced relationship with their greater environment. Gorging themselves on the sea urchins that grazed among the kelp, these small charismatic mammals seemed to give little back in return. But as Estes dug deeper, he unearthed a far more complex relationship between the otter and its underwater environment, discovering that otters play a critical role in driving positive ecosystem dynamics. While teasing out the connective threads, he began to question our assumptions about ecological relationships. These questions would ultimately inspire a lifelong quest to better understand the surprising complexity of our natural world and the unexpected ways we discover it. Serendipity tells the story of James Estes’s life as a naturalist and the concepts that have driven his interest in researching the ecological role of top-level predators. Using the relationships between sea otters, kelp, and sea urchins as a touchstone, Estes retraces his investigations of numerous other species, ecosystems, and ecological processes in an attempt to discover why ecologists can learn so many details about the systems in which they work and yet understand so little about the broader processes that influence these systems. Part memoir, part natural history, and deeply inquisitive, Serendipity will entertain and inform readers as it raises thoughtful questions about our relationship with the natural world.

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.

Otters are highly charismatic and popular animals of very considerable concern to conservationists worldwide. Written by the pre-eminent authority in the field, this book builds on the reputation of the author's landmark monograph of the European otter, Wild Otters (OUP, 1995). Furthermore, its broader scope to include all species of otter in North America as well as Europe and elsewhere leads to a deeper synthesis that greatly expands the book's overall relevance and potential readership. Aimed at naturalists, scientists and conservationists, its personal style and generously illustrated text will appeal to amateurs and professionals alike. It emphasises recent research and conservation management initiatives for all 13 species of otter worldwide, incorporates recent molecular research on taxonomy and population genetics, and discusses the wider implications of otter studies for ecology and conservation biology. As well as enchanting direct observations of the animals, there is guidance about how and where to watch and study them. From otters in the British and American lakes and rivers, to sea otters in the Pacific Ocean, giant otters in the Amazon and other species in Africa and Asia, this book provides an engaging approach to their fascinating existence, to the science needed to understand it, and to the very real threats to their survival.

Discusses the ocean ecosystem and the role of the sea otter as a keystone species in helping to maintain it, describing the otter's place on the food chain and what would happen if the sea otter were to become extinct.

Community ecology is the study of the interactions between populations of co-existing species. Co-edited by two prominent community ecologists and featuring contributions from top researchers in the field, this book provides a survey of the state-of-the-art in both the theory and applications of the discipline. It pays special attention to topology, dynamics, and the importance of spatial and temporal scale while also looking at applications to emerging problems in human-dominated ecosystems (including the restoration and reconstruction of viable communities). Community Ecology: Processes, Models, and Applications adopts a mainly theoretical approach and focuses on the use of network-based theory, which remains little explored in standard community ecology textbooks. The book includes discussion of the effects of biotic invasions on natural communities; the linking of ecological network structure to empirically measured community properties and dynamics; the effects of evolution on community patterns and processes; and the integration of fundamental interactions into ecological networks. A final chapter indicates future research directions for the discipline.