Stock assessment of the Indian squid Loligo duvauceli Orbigny

Abstract

The present status of the fishery, biology and stock assessment of the India squid Loligo duvauceli
\nOrbigny was studied, based on the data collected at different centres on both the coasts of India for
\n1979-1989. The production had increased by over 280% in 3 states on the west coast, viz. Kerala,
\nMaharashtra and Gujarat. These states accounted for about 80% of the all-India squid production
\n(23,941 t in 1989). Trawl is the main gear, taking 86% of the total squid landings. The fishing effort
\nand squid catch on the east coast was comparatively more in the third quarter. On the west coast the
\nfirst and fourth quart«^ were the most productive. The natural mortality rates calculated based on
\ndifferent levels of M/K values (1.5, 2, 2.5 and 3) showed that they ranged from 1.35 to 2.7 for males
\nand from 1.95 to 3.9 tor females on the east coast; from 1.2 to 2.4 for males and from 1.65 to 3.3 for
\nfemales on the west coast. On both the coasts the values for females were higher than for males. The
\nmaximum fishing mortality (1.2 - 4.3) under different M/K values for males was at the size of 85 mm,
\nand for females (5.8 - 6.7) at 175 mm on the east coast. For the west coast males the maximum fishing
\nmortality (3.3 - 4.3) was at the size of 230 mm and for females (2.3 - 3.8) at 130 mm. The standing
\nstock of males was higher than that of females on the east coast, with a reverse order on the west coast.
\nThe MSY and mean biomass at different M/K levels were also estimated for males and females separately
\nfor each coast. The present level of exploitation was at the optimum level on both the coasts.