Size Selectivity of 35-mm Square and Diamond Mesh Cod-Ends in Bottom Trawls for Parapeneopsis stylifera and Stolephorus indicus off the East Coast of India

Abstract

Trawling systems have been global topic with concern on sustainable fisheries and management due to non-selective and caught whatever it comes in the net. Pertaining to the issue n experimental fishing was conducted to compare the selectivity of 35mm square and diamond cod-ends of commercial bottom trawl net using cover cod-end method on selected two species viz., Kiddi shrimp (Parapeneopsis stylifera) and the Indian anchovy (Stolephorus indicus) off Kakinada, Andhra Pradesh, India.  The L25, L50 and L75 values of P.stylifera for 35mm square mesh cod-end was 7.33, 11.0 and 14.6cm while the selection range (SR), selection factor (SF) and selection ratio (Sr) was 7.32, 0.31 and 0.20 respectively. From the 35mm diamond mesh cod-end for P.stylifera, the observed L25, L50 and L75 parameters was 3.70, 6.53 and 9.35cm while the selection ranges (SR), selection factor (SF) and selection ratio (Sr) was 5.64, 0.18 and 0.16 respectively. From the 35mm square mesh cod-end for Indian Anchovy (S.indicus), the observed L25, L50 and L75 values was 4.91, 8.07 and 9.79 cm while selection range (SR), selection factor (SF) and selection ratio (Sr) was 4.88, 0.23 and 0.13 respectively. From 35mm diamond mesh cod-end for P.stylifera, the L25, L50 and L75 value was 3.26, 6.50 and 9.71 cm respectively while selection range (SR), selection factor (SF) and selection ratio (Sr) was recorded at 6.45, 0.18 and 0.18 respectively. The observed results concluded that the 35mm square mesh have superior in selectivity with compared to 35mm diamond mesh cod-end of bottom trawl net.