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Sharks and their relatives, the rays and chimaeras, are the diverse group of cartilaginous fishes that have evolved over 400 million years. Historically considered of low economic value to large-scale fisheries, today many of these fishes have become the target of directed commercial and recreational fisheries around the world, and they are increasingly taken in the by-catch of fisheries targeting other species. This report emphasizes the widely-acknowledged need to improve shark fishery monitoring, expand biological research and take management action. It serves as an introduction to the ecology, status and conservation of the sharks and their relatives for a general audience. Shark fisheries can only be managed sustainably, and shark populations remain viable, with the introduction of new conservation and management initiatives.
Quantitative modeling methods have become a central tool in the management of harvested fish populations. This book examines how these modeling methods work, why they sometimes fail, and how they might be improved by incorporating larger ecological interactions. Fisheries Ecology and Management provides a broad introduction to the concepts and quantitative models needed to successfully manage fisheries. Walters and Martell develop models that account for key ecological dynamics such as trophic interactions, food webs, multi-species dynamics, risk-avoidance behavior, habitat selection and density-dependence. They treat fisheries policy development as a two-stage process, first identifying strategies for varying harvest in relation to changes in abundance, then finding ways to implement such strategies in terms of monitoring and regulatory procedures. This book provides a general framework for developing assessment models in terms of state-observation dynamics hypotheses, and points out that most fisheries assessment failures have been due to inappropriate observation model hypotheses rather than faulty models for ecological dynamics. Intended as a text in upper division and graduate classes on fisheries assessment and management, this useful guide will also be widely read by ecologists and fisheries scientists.
Few places in the world can claim such a diversity of species as the Gulf of California (Sea of Cortez), with its 6,000 recorded animal species estimated to be half the number actually living in its waters. So rich are the Gulf's water that over a half-million tons of seafood are taken from them annuallyÑand this figure does not count the wasted by-catch, which would triple or quadruple that tonnage. This timely book provides a benchmark for understanding the Gulf's extraordinary diversity, how it is threatened, and in what ways it isÑor should beÑprotected. In spite of its dazzling richness, most of the Gulf's coastline now harbors but a pale shadow of the diversity that existed just a half-century ago. Recommendations based on sound, careful science must guide Mexico in moving forward to protect the Gulf of California. This edited volume contains contributions by twenty-four Gulf of California experts, from both sides of the U.S.-Mexico border. From the origins of the Gulf to its physical and chemical characteristics, from urgently needed conservation alternatives for fisheries and the entire Gulf ecosystem to information about its invertebrates, fishes, cetaceans, and sea turtles, this thought-provoking book provides new insights and clear paths to achieve sustainable use solidly based on robust science. The interdisciplinary, international cooperation involved in creating this much-needed collection provides a model for achieving success in answering critically important questions about a precious but rapidly disappearing ecological treasure.
Describes over 40 major sustainability issues, ranging from the management of natural resources (waste, water, energy, etc.), to development control, satisfaction of tourists and host communities, preservation of cultural heritage, seasonality, economic leakages, or climate change. For each issue, indicators and measurement techniques are suggested with practical information sources and examples. Contains a procedure to develop destination-specific indicators, their use in tourism policy and planning processes, as well as applications in different destination types (e.g. coastal, urban, ecotourism, small communities). Numerous examples and 25 case studies provide a range of experiences at the company, destination, national and regional levels from all continents.
The uplifting, adventure-filled memoir of one groundbreaking scientist’s quest to develop new ways to fight illness and disease through the healing powers of plants. “A fascinating and deeply personal journey.” ­—Amy Stewart, author of Wicked Plants and The Drunken Botanist Traveling by canoe, ATV, mule, airboat, and on foot, Dr. Cassandra Quave has conducted field research everywhere from the flooded forests of the remote Amazon to the isolated mountaintops in Albania and Kosovo—all in search of natural compounds, long-known to traditional healers, that could help save us all from the looming crisis of untreatable superbugs. Dr. Quave is a leading medical ethnobotanist—someone who identifies and studies plants that may be able to treat antimicrobial resistance and other threatening illnesses—helping to provide clues for the next generation of advanced medicines. And as a person born with multiple congenital defects of her skeletal system, she's done it all with just one leg. In The Plant Hunter, Dr. Quave weaves together science, botany, and memoir to tell us the extraordinary story of her own journey.