Fishery, biology and stock assessment of spotted seer, Scomberomorus guttatus (Bloch & Schneider) off Andhra Pradesh

Abstract

The fishery, biology and stock of the spotted seerfish, Scomberomorus guttatus (Bloch & Schneider) along Andhra Pradesh was studied during 2012-2014. The annual average landing of spotted seer during the period along Andhra coast was 2,614 t. Major contributors were trawlnets-1,104 t (42.2%) and gillnets-950 t (36.3%). Catches were higher during August-December. Length-weight relationship varied significantly between males, females and indeterminates. Growth was isometric in males and allometric in females and indeterminates. Overall sex ratio was 1:1.87. Length at first maturity was 38.9 cm. Peak spawning was observed during November-April. Higher Gonadosomatic index coincided with periods of peak spawning. Mature ovaries contained both maturing (0.41 mm-0.70 mm) and matured (0.71 mm-0.90 mm) ova. von Bertalanffy growth equation was Lt = 71.98 [1-e -0.23 (t + 0.0722)]. Natural mortality, fishing mortality and total mortality were 0.54, 0.49 and 1.03. Exploitation ratio was 0.48. Annual total stocks, biomass and Maximum Sustainable Yield were 8,546 t, 5,335 t and 2,747 t. A minor increase in yield and yield/recruit is possible by increasing the present level of fishing by 20%.