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.

Klappentext

This book discusses effects of predation by sea otters in nearshore benthic communities of the North Pacific. It includes chapters written by researchers in kelp forest, rocky intertidal, and soft sediment habitats. They review current knowledge and areas of controversy, present new data, and identify needs for additional study. In the concluding chapters areas of consensus as well as barriers to overgeneralization and accurate prediction are noted. This is the first technical book focusing on empirical studies of effects of a marine mammal on marine ecosystems. Researchers, fisheries and environmental conservation organizations will find this book a valuable study.

Inhalt
1 Introduction.- 2 A Review of the History, Distribution and Foraging Ecology of Sea Otters.- 2.1 Introduction.- 2.2 Evolution.- 2.3 History, Distribution and Present Status of Populations.- 2.4 Diet and Foraging Behavior.- 2.5 Summary.- 3 Sea Otter Foraging Habits and Effects on Prey Populations and Communities in Soft-Bottom Environments.- 3.1 Introduction.- 3.2 Soft-Bottom Foraging Habits.- 3.3 Prey Vulnerability and Patch Dynamics.- 3.4 Substrate Disturbance.- 3.5 Rocky and Soft Substrata.- 3.6 Future Research.- 3.7 Summary.- 4 Effects of Foraging by Sea Otters on Mussel-Dominated Intertidal Communities.- 4.1 Introduction.- 4.2 Models of Mussel-Dominated Communities.- 4.3 Sea Otters as Predators of Mussels.- 4.4 Case 1: Sea Otters and Mussels on the Coast of Central California.- 4.5 Case 2: Sea Otters and Mussels in Prince William Sound, Alaska.- 4.6 Discussion.- 4.7 Summary.- 5 Kelp Communities and Sea Otters: Keystone Species or Just Another Brick in the Wall?.- 5.1 Introduction.- 5.2 Kelp Community Structure.- 5.3 The Otter as a Keystone Species in California: Local or General?.- 5.4 Otter Effects: Geographic and Historical.- 5.5 Beyond Otters.- 5.6 A Model for Structure and Organization.- 5.7 Conclusions.- 5.8 Summary.- 6 Sea Otters, Sea Urchins, and Kelp Beds: Some Questions of Scale.- 6.1 Introduction.- 6.2 The Questions.- 6.3 The Evidence.- 6.4 Variation in Space and Time.- 6.5 Directions for Future Research.- 6.6 Summary.- 7 Effects of Sea Otter Foraging on Subtidal Reef Communities off Central California.- 7.1 Introduction.- 7.2 Study Sites.- 7.3 Methods.- 7.4 Results and Discussion.- 7.5 General Discussion and Conclusions.- 7.6 Summary.- 8 Fish Populations in Kelp Forests Without Sea Otters: Effects of Severe Storm Damage and Destructive Sea Urchin Grazing.- 8.1 Introduction.- 8.2 The System.- 8.3 Methods.- 8.4 Results and Discussion.- 8.5 General Discussion and Conclusions.- 8.6 Summary.- 9 The Effects of Kelp Forests on Nearshore Environments: Biomass, Detritus, and Altered Flow.- 9.1 Introduction.- 9.2 Habitat Model.- 9.3 Trophic Model.- 9.4 Hydrodynamic Model.- 9.5 Discussion.- 9.6 Summary.- 10 Sea Otters and Nearshore Benthic Communities: A Theoretical Perspective.- 10.1 Introduction: Regulatory Issues.- 10.2 Ecological and Regulatory Parallels.- 10.3 Measures of Ecosystem Health.- 10.4 Risk Assessment: Predicting Fate, Transport, and Effects of Otters.- 10.5 Summary.- 11 Concluding Remarks.- 11.1 Introduction.- 11.2 Patterns, Processes and Paradigms in Communities Occupied by Sea Otters A View Among Systems, and Through Space and Time.- 11.3 Variation in Community Structure.- 11.4 Future Research Needs.- 11.5 The Approach to Variation A Philosophical Perspective.- References.