Sharks in Danger

Abstract

This book reviews the current status of, and threats to, shark populations globally with special reference to the basking shark and the great white shark.

This book outlines why sharks are a valuable resource, identifies threats to sharks and where they occur and reviews what we need to know about sharks in order to protect them. Fisheries management procedures are investigated to target areas requiring future research and implementation. Conservation initiatives, legislation, and international agreements are reviewed and future measures suggested. Case histories on the basking shark and the great white shark detail threats specific to these species and identify research and management requirements.

Sharks are a valuable resource both directly through shark watching trips, medical research and commercial and recreational fisheries, and indirectly through the selection pressure they exert on our teleost fisheries, the part they play in maintaining the ecology of the ocean and their intrinsic scientific value. Identifiable threats to sharks are recreational and commercial overfishing and environmental degradation rendered by man such as development of nursery and mating zones and disturbance of the marine environment through netting and trawling. Particular threats to sharks worldwide are the exploitative fin and cartilage trades. Information required for the sustainable management of sharks include life history episodes such as reproductive rates, vulnerable life stages, population dynamics and spatial and temporal distribution. An indepth analysis of white sharks and basking sharks reveal similarities in their reproductive strategies such that both species will follow similar management practices.

In reviewing fishery management practises it was found that sustainable management plans must be based upon reproductive rates requiring knowledge of life histories. Life history information is often required for legislative protection such that extremely rare species cannot be considered. Protective legislation should be targeted towards individual species and vulnerable life stages, particularly nursery and mating zones. Further legislation should be enacted to improve current knowledge through data collection.