PENGUKURAN AKUSTIK TARGET STRENGTH IKAN SELAR BENTONG (Selar boops) SECARA TERKONTROL DI PERAIRAN PULAU TIKUS KOTA BENGKULU

Abstract

Metode akustik dapat digunakan dalam memperkirakan kelimpahan ikan. Metode ini membutuhkan informasi Target Strength (TS) untuk setiap spesies target. TS merupakan parameter penting sebagai faktor skala dalam pendugaan stok secara akustik. Penelitian ini bertujuan menganalisis karakteristik TS ikan selar bentong (Selar boops) dan mencari rumusan hubungan panjang baku dan panjang gelembung renang ikan selar bentong (Selar boops) terhadap nilai TS pada frekuensi transmisi 38 kHz. Pengukuran dilakukan secara terkontrol dimana ikan ditempatkan di bawah transduser dengan metode tethered menggunakan echosounder Simrad EK-60 pada frekeuensi 38 kHz. Hasil penelitian diperoleh nilai TS ikan selar bentong (Selar boops) berukuran panjang baku 16 cm sampai 20 cm menyebar pada kisaran –51,62 dB sampai dengan -39,03 dB, dengan nilai rata – rata -46,67 dB. Model hubungan TS terhadap panjang baku ikan selar bentong yaitu TS = 30,1 Log SL -84,49. Model hubungan TS terhadap panjang gelembung renang yaitu TS = 20,32 Log SB -62,34.ACOUSTIC CONTROLLED MEASUREMENT OF TARGET STRENGTH OF SELAR BENTONG FISH (SELAR BOOPS) IN TIKUS ISLAND WATER, BENGKULU CITY. Acoustic methods can be used to estimate fish abundance. This method requires Target Strength (TS) information for each target species. TS is an important parameter as a scale factor in acoustic estimation of stock. This study aims to analyze the TS characteristics of Selar bentong fish (Selar boops) and look for the formulation of the relationship between the standard length and length of the swim bladder in Selar bentong fish (Selar boops) to the TS value at the transmission frequency of 38 kHz. Measurements were carried out in a controlled manner where the fish were placed under the transducer with a tethered method using the Simrad EK-60 echosounder at a frequency of 38 kHz. The results showed that the TS value of Selar bentong (Selar boops) with a standard length of 16 cm to 20 cm spread over the range of -51.62 dB to -39.03 dB, with an average value of -46.67 dB. The relationship model of TS to the standard length of Selar bentong fish was TS = 30.1 Log SL -84.49. The relationship model of TS to swim bladder length was TS = 20.32 Log SB -62.34.