Design and technical characteristics of shark gillnet operating in Mumbai coast

Abstract

This paper deals with design and general features of shark gillnets operated along Mumbai coast. A PA monofilament of 0.60 to 1.0 mm diameter and selvedge meshes of PE of 1 to 2 mm diameter were used for shark set gillnets along Mumbai coast. Mesh size of the main webbing ranged from 120 to 200 mm with average of 144.4 ± 10.83 mm and rigged with a hanging coefficient of 0.41 to 0.51 with average of 0.42 were commonly used. A hung length ranging from 40 to 105 m with mean of 59 ± 10.37 with total hung depth varying from 6.42 to 10.58 m with average of 8.15 ± 0.49 m. Shark gillnet had a total length of 260 to 456 m with mean of 350.71 ± 28.53 m. The nets were operated mostly at a depth up to 18 m very near to the shore and were of set type of gillnet. Polyamide (PA) monofilament netting of 0.16 to 0.32 mm diameter and of mesh size 26-200 mm were generally used for construction of gillnets throughout the Mumbai coast. Polyamide (PA) monofilament has completely replaced PA multifilament in all the nets except those targeted i.e. white sardine and seerfish.