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Marine Fisheries Ecology von Jennings, Simon (eBook)

  • Erscheinungsdatum: 16.04.2013
  • Verlag: Wiley-Blackwell
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Marine Fisheries Ecology

This topical and exciting textbook describes fisheries exploitation, biology, conservation and management, and reflects many recent and important changes in fisheries science. These include growing concerns about the environmental impacts of fisheries, the role of ecological interactions in determining population dynamics, and the incorporation of uncertainty and precautionary principles into management advice. The book draws upon examples from tropical, temperate and polar environments, and provides readers with a broad understanding of the biological, economic and social aspects of fisheries ecology and the interplay between them. As well as covering 'classical' fisheries science, the book focuses on contemporary issues such as industrial fishing, poverty and conflict in fishing communities, marine reserves, the effects of fishing on coral reefs and by-catches of mammals, seabirds and reptiles. The book is primarily written for students of fisheries science and marine ecology, but should also appeal to practicing fisheries scientists and those interested in conservation and the impacts of humans on the marine environment.

  • particularly useful are the modelling chapters which explain the difficult maths involved in a user-friendly manner
  • describes fisheries exploitation, conservation and management in tropical, temperate and polar environments
  • broad coverage of 'clasical' fisheries science
  • emphasis on new approaches to fisheries science and the ecosystem effects of fishing
  • examples based on the latest research and drawn from authors' international experience
  • comprehensively referenced throughout
  • extensively illustrated with photographs and line drawings

Produktinformationen

    Format: ePUB
    Kopierschutz: AdobeDRM
    Seitenzahl: 432
    Erscheinungsdatum: 16.04.2013
    Sprache: Englisch
    ISBN: 9781118688106
    Verlag: Wiley-Blackwell
    Größe: 10041 kBytes
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Marine Fisheries Ecology

1
Marine fisheries ecology: an introduction
1.1 Introduction

Humans have fished since prehistoric times, but in the last 50 years fisheries have expanded faster than ever before. Marine fisheries now yield around 90 million tonnes per year, more than 80% of global fish production. Catches have increased because a growing human population demands more food and because improved technology has simplified capture, processing, distribution and sale. Greater fishing power and increased competition between fishers, vessels or nations has led to the economic collapse of some fisheries that had flourished for centuries. The resultant reductions in fish production, income and employment are usually seen as undesirable by society. This is why governments intervene to regulate fisheries.

Effective fisheries management requires that managers work towards clearly specified objectives. These may be biological, economic and social. Thus, the fisheries scientist has to understand links between different disciplines and the ways in which science can usefully inform the manager. This chapter introduces the history and diversity of the world's fisheries, their current status and the main problems they face. This provides a basis for suggesting why we need to conserve fisheries and the marine environment and identifies the main objectives of fishery management.

1.2 Fisheries of the world
1.2.1 History of fisheries
Fisheries in ancient civilizations

Humans living in coastal areas have always eaten marine organisms. Initially, animals and plants were simply collected by hand from the shore, but more effective fishing methods were soon developed. Fish hooks fashioned from wood and bone have been found at sites dated 8000 BC, and there are references to fisheries in Greek, Egyptian and Roman texts. In Egypt, nets and spears were in use by 2000 BC. As the Pacific Islands were colonized, fish provided protein on islands with few other animal resources, and the successful migration of Melanesian and Polynesian people often depended on their ability to catch reef fish. Fishers were aware of cycles in the abundance of species they caught, and the Greeks used storage ponds and fish farms to ensure a continuity of supply. Latterly, fish could be preserved by salting and drying, allowing fishers to work further from their home ports and fish products to be traded and exported.

Pre-industrial fisheries

As nations developed their seafaring skills and began to explore the oceans, they discovered abundant fish resources. Explorers reported that huge numbers of cod Gadus morhua (Gadidae) could be found off Newfoundand, and by the early 1500s, French and Portuguese fishers were already crossing the north Atlantic Ocean to fish for them. The cod were caught with baited hooks, dried and shipped to the Mediterranean countries and the Antilles where they were known as bacalao and fetched high prices. Subsequently, English vessels joined the fishery. The countries that fished for cod were the major sea powers of the time and fought to control trade routes. They were often at war and many fishing vessels were lost. In the Anglo-Spanish war of 1656-1659, 1000 English vessels were sunk. Cod were such a valuable commodity that the vessels were also targeted by pirates. Moroccan pirates would rob vessels returning to Mediterranean ports, and the Sallee rovers, French, Spanish and English pirates under the Turkish flag, attacked fishing boats in so many areas that the fishers eventually sailed in convoy for protection. In later years, the cod fishery on Georges Bank and Grand Bank was increasingly fished by boats from New England ports. By the midnineteenth century, cod were caught with hook and line from fleets of eight or more small dories that transferred their daily catches to a larger schooner for storage in i

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