Monsoonal variation in catch of Rastrelliger kanagurta at east coast of Peninsular Malaysia

Abstract

Indian mackerel, Rastrelliger kanagurta plays an important role in marine fisheries of Malaysia. Distribution of R. kanagurta was reported to be influenced by various oceanographic conditions. In the waters off east coast of Peninsular Malaysia, monsoon is the main factor influencing this region. In this study, R. kanagurta catch data were categorised to four monsoon periods: southwest monsoon (SW) in May-Sep, 1st-intermonsoon (1st-inter) in Apr, northeast monsoon (NE) in Nov-Mac and 2nd-intermonsoon (2nd-inter) in Oct. During 2nd-intermonsoon, fish catch of R. kanagurta was found highest significantly among all four monsoon periods, while fish catch during northeast, southwest and 1st-intermonsoon did not differed significantly. COAST was identified as the most important variable in the RF models for northeast and southwest monsoon. From RF models, fish catch was highest when fishing effort was performed near the coast. During the 1st-intermonsoon, high fish catch was found with increasing CHL. During 2nd-intermonsoon, further studies are needed as variables used in this study could not contribute well in the RF model.