Conservation of Fish and Shellfish Resources (eBook)

Managing Diversity

Graham A.E. Gall, Jim E. Lannan, Colin E. Nash, J. E. Thorpe (Herausgeber)

eBook Download: PDF

1995 | 1. Auflage
206 Seiten
Elsevier Science (Verlag)
978-0-08-052981-3 (ISBN)

Infos

Fish and shellfish comprise annually nearly 70-million tons of the world's edible animal protein. However, because of this demand, previously vast stocks have often been exhausted to the point of near extinction. The first book of its kind in the area of freshwater/marine biodiversity, this extensive work reviews the present status of genetic resource management, its needs and constraints, various intervening human factors such as pollution and overfishing, and problems posed by different species and life-styles. This discussion of the conservation of fish and shellfish resources is illustrated by four diverse groups: Atlantic salmon, cupped oysters, common and Chinese carp, and Nile tilapia. These results, produced by the collaboration of nine leading population and production geneticists, aquaculturists, and behavioral and developmental ecologists should become a fundamental resource useful to biologists, scientists and advisors exploring current issues in the fishery sciences.

Key Features
* Four page color plate section
* Database of key organizations for contact purposes
* Foreword by Dr. Mike Strauss, Am. Assoc. for the Advancement of Science; and Dr. Peter Day, Rutgers University
* Four in-depth case studies by international experts
* Editors are major names in marine/freshwater fisheries science
* Originally sponsored and reviewed by U.S. National Academy of Sciences

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Fish and shellfish comprise annually nearly 70-million tons of the world's edible animal protein. However, because of this demand, previously vast stocks have often been exhausted to the point of near extinction. The first book of its kind in the area of freshwater/marine biodiversity, this extensive work reviews the present status of genetic resource management, its needs and constraints, various intervening human factors such as pollution and overfishing, and problems posed by different species and life-styles. This discussion of the conservation of fish and shellfish resources is illustrated by four diverse groups: Atlantic salmon, cupped oysters, common and Chinese carp, and Nile tilapia. These results, produced by the collaboration of nine leading population and production geneticists, aquaculturists, and behavioral and developmental ecologists should become a fundamental resource useful to biologists, scientists and advisors exploring current issues in the fishery sciences. - Four page color plate section- Database of key organizations for contact purposes- Foreword by Dr. Mike Strauss, Am. Assoc. for the Advancement of Science; and Dr. Peter Day, Rutgers University- Four in-depth case studies by international experts- Editors are major names in marine/freshwater fisheries science- Originally sponsored and reviewed by U.S. National Academy of Sciences

Textauszug

SUMMARY

Water covers more than two-thirds of the earth’s surface. Beneath a variety of marine and freshwater ecosystems is a wealth of biological diversity, much of which is yet to be discovered or fully described. The multicellular metazoan species of the world’s aquatic environments number at least 150,000. Although the number of aquatic species is fewer than all terrestrial species, the number of phyla in the oceans represents a breadth of diversity that is far greater.

The fish and fisheries products derived from the world’s oceans, lakes, and rivers make important contributions to human nutrition and health. They are also a vital part of the economies of many societies. In 1991, the global commercial fisheries’ harvest, including that from aquaculture and culture-based fisheries, was approximately 97 million metric tons. Of this amount, 71% was intended for human consumption. Imports and exports of fish and shellfish products worldwide in 1991 were valued at $82.0 billion. This included 13 million metric tons of crustaceans and molluscs harvested worldwide in 1991, with a value of $29.7 billion as fresh, frozen, dried, or salted commodities.

The world’s aquatic animals comprise a resource that fulfils many human needs today and provides a source of genetic diversity from which future needs can be met. However, a variety of human activities threaten the existence of aquatic animal species. The majority of fish and shellfish are harvested from populations that live in natural environments. Overharvesting in these areas coupled with pollution, environmental degradation, and loss of habitat raise the potential for significant depletion or loss of important aquatic resources. For the many aquatic species not of commercial importance, such threats can be even greater. The introduction of exotic fish into lakes and streams can produce new fisheries, but at the expense of creating drastic upheavals in the ecosystem that can lead to the loss of endemic populations and species.

‘Variability of biological matter is the sine qua non for the ability of organisms to cope with the uncertainty of the environment’ (Conrad, 1983). The genetic structure of a species is the repository of that variability, and its conservation is essential to maintain the genetic continuity of that species in the face of continual environmental change.

This book addresses the need for increased efforts so that the management practices used in global fishery activities can be based on sound genetic principles. It stresses the biological diversity of aquatic species and the unique constraints to genetic management. Too often, the long-term effects of management practices on population genetics have been overlooked. To ensure that future human needs will be met requires greater consideration for managing and conserving the genetic diversity of the world’s aquatic animal resources.

BARRIERS TO MANAGING AQUATIC ANIMAL GENETIC RESOURCES

Several factors limit effective management or conservation of the genetic resources of aquatic animals, ranging from a lack of scientific information or technology to the need for appropriate programmes, institutions, or national and international policies.

The Lack of Information

Little is known about the genetics and evolutionary biology of most aquatic species. Aquatic animals are far more difficult to observe than terrestrial species, and genetic investigations on aquatic animals have not received adequate priority or funding. A comprehensive inventory of aquatic species and their genetic diversity does not exist. For some of the deepest portions of the oceans, the barrier to acquiring information is the direct result of technological difficulties. For the coastal zone, as for the tropical rain forests of the terrestrial environment, it is probable that more organisms exist there than have been described.

The vast diversity of aquatic species and the differing means by which they must be conserved confound the development of appropriate management strategies and programmes. Only a small fraction of the aquatic species are considered to be economically important. A comparatively large amount of information exists for these species. To illustrate the diversity of genetic structure of aquatic animal populations, and the differing approaches necessary for their conservation, four species with widely differing life-styles are discussed in Part Two of this book, namely: a migratory fish, Atlantic salmon (Salmo salar); a sedentary invertebrate, cupped oysters of the genus Crassostrea; a group of cultured non-migratory fishes, the common carp (Cyprinus carpio) and the Chinese carps (silver, Hypophthalmichthys molitrix; bighead, Aristichthys nobilis; grass, Ctenopharyngodon idella; black, Mylopharyngodon piceus; and mud carp, Cirrhina molitorella); and a fish with a broad range of intrageneric interactions, the Nile tilapia (Oreochromis niloticus). These are used to illustrate the diversity of challenges that confront numerous economically important aquatic species. There are many more species that could become important as sources of food, industrial, or pharmaceutical products or as indicators of environmental health.

Lack of Institutional Leadership

The responsibility and jurisdiction for conserving aquatic genetic resources is often poorly defined. In many nations, the management of aquatic resources and the regulation of human activities that affect them are not within the domain of any single institution or sector.

Lack of Conservation Focus

Genetic considerations have not been given a high priority in the management of aquatic resources. Relatively few programmes are designed for the express purpose of conservation. Many programmes have been enacted primarily for environmental management or species protection. Although these programmes may incidentally provide some degree of genetic resource conservation, most of them are concerned with population size and treat all individuals in the population as being genetically equivalent.

STRATEGIES FOR CONSERVATION AND MANAGEMENT

No single management strategy exists for minimizing or ameliorating the genetic risks associated with activities that affect aquatic species. Conservation management programmes must be considered on a species-by-species, case-by-case basis, but within a broad ecosystem context. At the very least, management plans must consider the

• nature of the resources;

• characteristic components of diversity of the species;

• genetic processes influencing diversity; and

• natural and human events or interventions that may place the genetic resources at risk.

If management programmes fail to conserve genetic resources, more extreme policy and management actions must be taken to prevent further genetic deterioration or extinction of species. For each species or population a determination of the most appropriate in situ or ex situ conservation must be made.

INSTITUTIONAL EFFORTS TO MANAGE AQUATIC GENETIC RESOURCES

Many of the international bodies involved in conserving aquatic species are international fisheries commissions, such as the European Inland Fisheries Advisory Commission, the Committee for Inland Fisheries of Africa, and the Indo-Pacific Fisheries Commission. Some of them were established through conventions or treaties fashioned to prevent the overharvesting of certain species. Although the commissions were not founded to conserve genetic resources, most of them now recognize the importance of genetic resources, and some have sponsored genetic research to provide information for resource management decisions. Given the mandate, international fisheries commissions could make important contributions to conserving the genetic resources of species harvested in international waters, as well as migratory species that inhabit the waters of two or more nations.

National policies and legislation that affect aquatic species are broad and varied. In a survey of scientists worldwide, few of the respondents indicated that their nations considered genetic conservation to be a separate resource management concern. Most of them stated that their nations had some form of regulation to prevent overharvesting of fishery resources and to control pollution or other activities that alter aquatic habitats. Many also indicated that their countries regulate the importation of exotic species.

RECOMMENDATIONS

The conservation of aquatic animal genetic resources will require coordinated actions on a global scale that include multilateral agreements and unilateral actions to develop and implement appropriate policies. These activities must be reinforced and enacted at national, regional, and local levels. Success necessitates greater public awareness of the importance of aquatic genetic resources and the need to conserve their genetic diversity. Major research, education, and training efforts will be needed to develop and apply technologies and to disseminate information to managers, policymakers, students, and the general public. Our principal recommendations for addressing these issues follow. Additional information and recommendations can be found...

Produkt-Details

• Erscheint lt. Verlag: 20.6.1995
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Biologie ► Genetik / Molekularbiologie
• Themenwelt: Naturwissenschaften ► Biologie ► Limnologie / Meeresbiologie
• Themenwelt: Naturwissenschaften ► Biologie ► Ökologie / Naturschutz
• Themenwelt: Technik
• Themenwelt: Wirtschaft
• Themenwelt: Weitere Fachgebiete ► Land- / Forstwirtschaft / Fischerei
• ISBN-10: 0-08-052981-X / 008052981X
• ISBN-13: 978-0-08-052981-3 / 9780080529813