DINAMIKA POPULASI DAN ESTIMASI RASIO POTENSI PEMIJAHAN IKAN LEMURU (Sardinella lemuru Bleeker, 1853) DI TELUK PRIGI, JAWATIMUR

Abstract

Ikan lemuru (Sardinella lemuru) berperan sangat penting bagi industri pengalengan ikan di Indonesia dan juga perikanan rawai tuna yang beroperasi di Samudera Hindia sebagai umpan. Aktivitas penangkapannya dilakukan secara terus-menerus sepanjang tahun sehingga diperlukan upaya pengelolaan agar tetap lestari. Penelitian ini bertujuan untuk mengkaji parameter populasi sebagai dasar pengelolaan sumberdaya lemuru di Teluk Prigi. Contoh ikan diambil dari hasil tangkapan pukat cincin mini pada periode Februari hingga Oktober 2013 di Pelabuhan Perikanan Nusantara Prigi. Analisis parameter pertumbuhan menggunakan program FISAT dan rasio potensi pemijahan didasarkan pada lembar kerja SPR pada ukuran panjang dan umur ikan. Laju pertumbuhan lemuru tergolong cepat sehingga berumur pendek. Laju kematian akibat penangkapan berkontribusi lebih besar daripada laju kematian alaminya. Kondisi stok lemuru berada pada kondisi lebih tangkap diindikasikan dengan E>0,5 dan SPR<20%. Diperlukan penerapan batas ukuran minimum ikan dengan meningkatkan selektivitas mata jaring dan juga pengurangan jumlah upaya penangkapan.

Bali sardinella (Sardinella lemuru) has an important role for the fishing canning industry in Indonesia and also tuna longline fisheries operating in the Indian Ocean as bait. However, fishing activities carried out continuously throughout the year, so that management of effort should be wasmade to maintain its sustainability. This study aims to estimate population parameters to determine the status of Bali Sardinella stock in Prigi Bay waters. Samples of mini purse seine catches were collected from Archipelago Fishing Port of Prigi during Februari to October 2013. Length frequency-based methods were used to estimate growth parameters, mortality and exploitation rate which was analysed with ELEFAN included in FISAT II software.Meanwhile, spawning potential ratio was analysed using SPR at size and age assessment in Microsoft Excel spreadsheet. The growth rate of Bali Sardinella was high so it has a short life relatively. Fishing mortality had a greater contribution than natural mortality. The current status of Bali Sardinella was estimated in overexploitation level indicated as E>0,5 and SPR<20%. Management measures required to address these issues by implementing a minimum size limit through increasing mesh size and also fishing effort need to be decreased at certain level.