Author: Glenn S. Vanstrum Publisher: Oxford University Press, USA ISBN: 9780195159370 Category : Nature Languages : en Pages : 372
Book Description
This book plunges the reader into the heart of the sea. Vanstrum, a photojournalist and M.D., has spent more than 25 years learning--often the hard way--about the world's oceans. Through this true account of misadventures in diving, surfing, and studying marine natural history and ecology, the book explores the human relationship to the living sea.--From publisher description.
Author: Felix G. Marx Publisher: John Wiley & Sons ISBN: 1118561368 Category : Science Languages : en Pages : 336
Book Description
Cetaceans (whales, dolphins, and porpoises) have fascinated and bewildered humans throughout history. Their mammalian affinities have been long recognized, but exactly which group of terrestrial mammals they descend from has, until recently, remained in the dark. Recent decades have produced a flurry of new fossil cetaceans, extending their fossil history to over 50 million years ago. Along with new insights from genetics and developmental studies, these discoveries have helped to clarify the place of cetaceans among mammals, and enriched our understanding of their unique adaptations for feeding, locomotion and sensory systems. Their continuously improving fossil record and successive transformation into highly specialized marine mammals have made cetaceans a textbook case of evolution - as iconic in its own way as the origin of birds from dinosaurs. This book aims to summarize our current understanding of cetacean evolution for the serious student and interested amateur using photographs, drawings, charts and illustrations.
Author: IUCN/SSC Polar Bear Specialist Group. Working Meeting Publisher: IUCN ISBN: 9782831706634 Category : Nature Languages : en Pages : 174
Book Description
These proceedings provide an overview of the ongoing research and management activities on polar bears in the circumpolar arctic. Together with the previous 12 proceedings, they provide an historic record of international efforts in protecting polar bears from over-harvest and document more recent concerns of threats arising from increased human activities in both the Arctic and in regions far beyond the realm of polar bears. More proactive management is needed to address limitations in the knowledge of population dynamics. New information indicates that the greatest future challenges to polar bear conservation may be ecological change in the Arctic due to climate change and pollution. The complex, global nature of the issues requires international cooperation and development of diverse, new approaches to address them.
Author: Carpentieri, P., Nastasi, A., Sessa, M., Srour, A. (eds.) Publisher: Food & Agriculture Org. ISBN: 9251346313 Category : Technology & Engineering Languages : en Pages : 339
Book Description
Bycatch – a term widely used to refer to part of the catch unintentionally caught during a fishing operation, in addition to target species, and consisting of the discards and incidental catch of vulnerable species – is considered one of the most important threats to the profitability and sustainability of fisheries, as well as to the conservation of the marine environment and ecosystems. Understanding the bycatch issue and adopting effective measures in order to reduce bycatch rates are essential steps towards minimizing the impacts on vulnerable species and ensuring both a sustainable fisheries sector and healthy seas. In the Mediterranean and the Black Sea, the incidental catch of vulnerable species – namely seabirds, sea turtles, elasmobranchs, marine mammals and macrobenthic invertebrates – represents one of several challenges for the industrial, semi-industrial and small-scale fisheries that coexist in the region, as well as for the diverse and sensitive ecosystems impacted. Typically, data on this issue have been collected in an opportunistic manner and in ways that make comparisons difficult. The annual absolute values of incidental catch of vulnerable species are not available: studies cover only a small portion of the total fishing activity and often present important knowledge gaps for many types of fishing gear, countries and/or subregions, as well as on temporal scales, for example, to establish reliable baselines. The result is that little is known of the scope of the problem, despite incidental catch being a significant pressure on the populations of vulnerable species, as well as a concern for fishers.This regional review is an attempt to compile, in one single document, all available data and historical records on the incidental catch of vulnerable species in the Mediterranean and Black Sea fisheries, obtained from existing literature, databases and other grey sources, and collated in a standardized and comparable way. The main objective is to provide comprehensive baseline information, earmark the main data gaps, as well as identify the most impacting types of fishing gear by taxonomic group. This work is a reminder of the importance of standardized data collection and the need to have baseline information in order to support decision-making in the identification of appropriate bycatch mitigation techniques, thus enabling analysis of their effectiveness and comparison over time and space, as well as facilitating the implementation of relevant conservation and/or management measures at the national, subregional and regional levels.
Author: Anita L. Lopez Publisher: ISBN: Category : Endangered species Languages : en Pages : 214
Book Description
The National Marine Fisheries Service (l\rNßS) conducted an aerial survey of the beluga whale population in Cook Inlet, Alaska, during 8-14 June 1999. The 41.5 hr surveywas flown in a twin-engine, high-wing aircraft at an altitude of 244 m (800 ft) and speed of 185 km/hr (100 kt) along a trackline 1.4 km from shore, consistent with annual surveys flown each year since 1993. The flights in 1999 included one or more surveys of coastal areas around nearly the entire Inlet and 1,790 km oftransects across the Inlet. Paired, independent observers searched on the coastal (left) side of the plane, where virtually all sightings occur, while a single observer and a computer operatorldatarecorder were on the right side. In addition, each day a different visitor observed from the left side. After finding beluga groups, a series of aerial passes were made to allow at least two pairs of primary observers to make four or more counts of each group. Inter-day counts ranged from 75 to160 belugas near the Susitna River (between the Beluga and Little Susitna Rivers), 13 to 43 in Knik Arm, and 17 to 30 in Chickaloon Bay, but no belugas were found in lower Cook Inlet. The sum of the aerial estimates (using median counts from each site, not corrected for missed whales) ranged from 197 to 221 whales, depending on observer. The index count for 1999 is 217 , which is slightly higher than the index counts for 1998 (193) but lower than all index counts by NMFS observers between 1993-97
Author: Jeanette A. Thomas Publisher: University of Chicago Press ISBN: 9780226795997 Category : Nature Languages : en Pages : 636
Book Description
Although bats and dolphins live in very different environments, are vastly different in size, and hunt different kinds of prey, both groups have evolved similar sonar systems, known as echolocation, to locate food and navigate the skies and seas. While much research has been conducted over the past thirty years on echolocation in bats and dolphins, this volume is the first to compare what is known about echolocation in each group, to point out what information is missing, and to identify future areas of research. Echolocation in Bats and Dolphins consists of six sections: mechanisms of echolocation signal production; the anatomy and physiology of signal reception and interpretation; performance and cognition; ecological and evolutionary aspects of echolocation mammals; theoretical and methodological topics; and possible echolocation capabilities in other mammals, including shrews, seals, and baleen whales. Animal behaviorists, ecologists, physiologists, and both scientists and engineers who work in the field of bioacoustics will benefit from this book.
Author: Whitlow W.L. Au Publisher: Springer Science & Business Media ISBN: 1461211506 Category : Science Languages : en Pages : 499
Book Description
Here, experts in different areas of the field provide an overview of the bioacoustics of whales and dolphins as well as a thorough introduction to the subject for investigators of hearing in other animals. Topics covered include the structure and function of cetacean auditory systems, the unique sound production system of odontocetes, acoustic communication, psychoacoustics, echolocation and models of sound propagation.
Author: Glenn S. Vanstrum
Author: Felix G. Marx
Author: IUCN/SSC Polar Bear Specialist Group. Working Meeting
Author: Donald J. Hansen
Author: Carpentieri, P., Nastasi, A., Sessa, M., Srour, A. (eds.)
Author: Anita L. Lopez
Author: Donald M. Schell
Author: 
Author: Jeanette A. Thomas
Author: Whitlow W.L. Au