Management techniques for elasmobranch fisheries

Abstract

This publication describes the scientific principles and techniques used for resource management of elasmobranch fisheries with emphasis on the particular context of elasmobranchs. The management characteristics of these fishes are described – their common bycatch character and their biological constraints on productivity (low growth rate, late maturity and low fecundity). Stock assessment of elasmobranchs is described in the context of management objectives in a wide management context. Special attention is given to accurate species identification given the prevalent aggregating of landings data across species, genera and often families in this group. Techniques and experiences for tagging elasmobranchs for population estimation are described as well as methods of genetic techniques for stock identification. Methods and problems involved in determining age, growth, fecundity and mortality rates are described and their use in age-structured models within the context of the reproductive biology of these fishes. Demographic models to determine the productivity of elasmobranch resources are described. Use of surveys to complement information derived from fisheries is described together with management measures. Last, practices of shark utilization are noted.