Estimating gillnet selectivity of Bluefish (Pomatomus saltatrix) by morphology


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İLKYAZ A. T.

SU URUNLERI DERGISI, cilt.35, ss.89-94, 2018 (ESCI İndekslerine Giren Dergi) identifier

  • Cilt numarası: 35 Konu: 1
  • Basım Tarihi: 2018
  • Doi Numarası: 10.12714/egejfas.2018.35.1.14
  • Dergi Adı: SU URUNLERI DERGISI
  • Sayfa Sayıları: ss.89-94

Özet

The dataset of the study consists of total length, fork length, head girth, maximum girth and weight measurements of 136 bluefish. The relationship between the total length and fork length of the product was TL = 1.1348xFL-0.8184; the relationship between the total length and weight was W = 0.0103xL(2.97). The relationships between the total length and head girth and between the total length and maximum girth of the sample were linear: the relationship of the total length and head girth was G(gill) = 0.5092xTL-0.0874; the relationship of the total length and maximum girth was G(max) = 0.5989xTL-0.8540. The statistical relationship between length and girth was used to obtain a theoretical gillnet selectivity equation for the species. In conclusion, a relationship of S(l)= phi[(C-G(gill))/0.4952]x[1-phi((C-G(max))/0.4255)] was determined between the stretched size of the mesh used in bluefish fishing and the catch rate. Using this equation, and considering the legal length and length at first maturity, the minimum mesh size of the gillnet for sustainable fishery was determined .