Length-Weight Relationship and Population Dynamics of Bombay Duck (Harpadon nehereus) in the Min River Estuary, East China Sea

Abstract

The length-weight relationship, patterns of growth, mortality and exploitation are fundamental and useful information for fishery management. Investigations were carried out to study the length-weight relationship, growth, mortality and exploitation of Harpadon nehereus in the Min River Estuary, East China Sea, in 2015. A total of 938 specimens ranging from standard lengths of 5.9 to 25.0 cm was subjected for analysis. The length-weight relationship of H. nehereus in the Min River Estuary was W = 0.0007 L3.81 (R2 = 0.96). The high value of b was verified to be influenced by the reproduction and feeding behaviours, which were different from those of H. nehereus in the Indian Ocean. The von Bertalanffy growth equation was derived as Lt = 26.9 (1-e −0.94 × (t - (−0.12))). The total, natural and fishing mortality rates were 3.27, 1.58 and 1.69 year−1, respectively. The exploitation level of H. nehereus stock was estimated to close to an appropriate fishing pressure on the stock. We recommend maintaining the fishing intensity and renewing the size of H. nehereus at first capture (Lc = 18.07 cm) in the Min River Estuary.