Growth, mortality rates and stock assessment of the cuttlefish Sepiella inermis (Ferussac and D'orbigny) in Saurashtra waters

Abstract

Age and growth of the cuttle fish Sepiella inermis was estimated from the length frequency data collected from trawl net operations in Veraval during 1979-83. Natural mortality coefficient (M) is estimated to be 2.1 and the total mortality coefficient (Z) estimated asper catch curve method are given. Stock assessment has been made. The exploitation rate, total mortality, instantaneous mortality, average annual stock have been estimated by cohort analysis. The continuous decline in the annual landings and average annual stock during 1979-83 is attributed to high fishing pressure in the shallow near shore waters off Veraval. Further observation on this fishery is felt essential to formulate suitable regulatory measures with due consideration on other major fisheries of the area.