Cakalang (Katsuwonus pelamis) is one of the leading export commodities landed at the Prigi Fishing Port (PPN Prigi). Skipjack tuna fisheries management conducted the conventional single-species Schaefer model which is often applied although it is not technically suitable for multispecies fishery. The application of feedback harvest control rule (HCR) is an alternative harvest strategy that has been successfully implemented and validated for multispecies fishery. This study estimated allowable biological catch by applying two harvest strategies, HCR feedback and Schaefer surplus production model using catch-effort data of skipjack tuna landed at PPN Prigi in the period 2010 - 2019. Model Schaefer pointed out that catches have exceeded the maximum sustainable yield () even employed low the fishing effort which was under the fishing mortality consistent with achieving MSY (). The application of feedback HCR that has been previously validated can be an alternative of harvest strategy for use in fisheries where only mixed species data is available. Key words: multispecies fishery, harvest strategy, Schaefer model, maximum sustainable yield, single-species approach

Abstract. Harlyan LI, Badriyah L, Rahman MA, Sutjipto DO, Sari WK. 2021. Harvest control rules of pelagic fisheries in the Bali Strait, Indonesia. Biodiversitas 23: 947-953. Multispecies pelagic fisheries have contributed as the main fishery production for the Bali Strait fisheries. To maintain the sustainability of the fish stock, sets of harvest control rules (HCRs) have been introduced in terms of fishery management. Conventional single-species surplus production models have been used extensively to determine the future annual allowable biological catch (ABC). However, they may not technically apply to multispecies fishery management. The feedback harvest control rule HCR has been validated and applied to maintain the catch variability of the multispecies fishery. This study aims to technically compare the use of the surplus production model and the feedback HCR in the ABC estimation. The catch and effort data series of the three dominant species from 2010-2019, collected from Pengambengan and Muncar fishing port, were analyzed by two HCRs, the Schaefer surplus production model and the feedback HCR to obtain the ABC. As a result, the Schaefer model showed a higher estimation of ABC than the feedback HCR because the feedback HCR may reflect the recent historical catch consistent with precautionary principles. The feedback HCR showed an initial step toward sustainably managing multispecies fisheries while dealing with unavailability in species-specific data conditions.

Skipjack tuna (Katsuwonus pelamis) is one of high economic valued pelagic fish on the south coast of Malang waters. This fish is usually caught by purse seine. This study was conducted at Sendang Biru Coastal Fishing Port Malang Regency from February to May 2021, aiming to find out the utilization rate and bioeconomic conditions of the skipjack tuna fishery. The study used descriptive methods. Statistical data on catches from 2011 to 2020 were used to apply bioeconomic analysis to calculate the maximum sustainable yield (MSY), maximum economic yield (MEY), total allowable catch (TAC), and free access equilibrium (FAE). Results showed that values of catch and effort at MSY level were 1,800 tons and 3,191 trips respectively with a value of TAC as much as 1,440 tons. While values of catch and effort at MEY reached 1,774 tons and 2,814 trips respectively with the highest profit obtained as much as IDR 34.12 billion. In addition, catch and effort at FAE level took place at 751 tons and 5,627 trips respectively. The utilization rate of skipjack tuna (K. pelamis) was 123%. In conclusion, the fish is in over-exploited condition hence the amount of effort must be decreased to maintain resources sustainability.

Perikanan di Selat Madura memiliki karakteristik multigear dan multispecies. Cantrang merupakan salah satu alat tangkap yang masih dioperasikan di Selat Madura meskipun menurut Peraturan Menteri Kelautan dan Perikanan Nomor / PERMEN-KP/ 2016 melarang adanya pengoperasian alat tangkap tersebut. Penelitian ini bertujuan untuk mengetahui hubungan panjang berat ikan hasil tangkapan cantrang dan mengetahui tingkat eksplotitasi sumberdaya ikan oleh alat tangkap cantrang berdasarkan nilai Cacth Per Unit Effort (CPUE). Penelitian ini dilaksanakan pada bulan Juli -Agustus tahun 2020 di Pelabuhan Perikanan Pantai Mayangan. Data yang dikumpulkan berupa data primer dan data sekunder. Data primer yaitu data panjang ikan (cm) dan berat ikan (kg) hasil tangkapan cantrang yaitu ikan kurisi, ikan swanggi, dan ikan beloso. Hasil perhitungan menunjukkan hubungan panjang dan berat ketiga ikan sampel bersifat allometris negatif. Hasil perhitungan CPUE paling tinggi berada pada tahun 2011 untuk semua ikan. Hasil tangkapan alat tangkap sangat fluktuatif, namun cenderung menurun beberapa tahun terakhir. Hasil penelitian ini dapat digunakan sebagai acuan dalam pengelolaan perikanan berkelanjutan terutama dalam pembuatan kebijakan berkaitan dengan kebijakan pengoperasian alat tangkap cantrang.