Growth, mortality and stock assessment of Arius arius (Hamilton, 1822) from Hooghly-Matlah estuary, West Bengal

Abstract

The growth, mortality, and stock assessment of Arius arius were estimated based on monthly length-frequency analysis data collected from the Hooghly-Matlah estuary of West Bengal, India from April 2017 to March 2018. The estimated growth parameters were as L_∞ = 278 mm, K = 0.97 yr^-1, and t₀ = -0.0889 years. The different mortality coefficients Z, M, and F were obtained as 5.25 yr^-1, 1.79 yr^-1, and 3.46 yr^-1, respectively. The calculated exploitation ratio (E) was found as 0.66, and the M/K value as 1.845 indicating overexploitation of the fish. The recruitment was found throughout the year with two peaks and the value of L_c was found at 56.00 mm. The estimated virtual population analysis (VPA) indicated that the highest fishing mortality (F) of 3.4499 was observed at the 190-200 mm length class, followed by 3.2393 from the 180-190 mm length class. The fishery was found at the overexploitation level and measures are needed to regulate it for promoting its sustainability.