Growth and maturation of roker Raja clavata L. in the Solway Firth

Authors

  • A. S. Nottage,

    1. Marine Laboratory, University of Strathclyde, Helensburgh, Dunbartonshire G84 0JQ, Scotland
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  • E. J. Perkins

    1. Marine Laboratory, University of Strathclyde, Helensburgh, Dunbartonshire G84 0JQ, Scotland
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    • *

      Now at Solway Marine Investigations, Grove Cottage, Birkby, Maryport, Cumbria CA 15 ORG.


Abstract

Two hundred and seventy-one Raja clavata taken by otter trawl from the Solway Firth were examined for size, sex and state of maturity. Size relationships for both sexes were similar. Total length and disc width were linearly related as were disc width with wing width. Males and females appear to mature at 42 and 45 cm disc width respectively. The Solway population is heavily exploited by an unrestricted commercial fishery and a considerable proportion (48·6%) of the presently retained catch is immature. It is suggested that fishing pressure has brought about a reduction in the size at which female fish mature.

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