Analisis perikanan cakalang (Katsuwonus pelamis) di Teluk Bone : hubungan aspek biologi dan faktor lingkungan

Abstract

Fishing activities targeting skipjack tuna (Katsuwonus pelamis) take place in the Bone Bay. The bay is part of the Indonesia Fisheries Management Area or WPPI 713 that covers Makassar strait, Flores sea and Bali sea. This study describes some biological characteristics of the skipjack tuna in three pre-defined fishing zones, i.e. the North Zone (Districts of Luwu, Luwu Utara, Luwu Timur, Wajo and Palopo city), the Centre Zone (District of Bone) and the South Zone (District of Sinjai). Such information is very important for developing fisheries management strategies in the bay. The objectives of the study are to analyze biological characteristics of the skipjack tuna caught in the Bay, to calculate and interpretate of CPUE of the fisheries, to analyze dynamics of fishing and fish production in relation to oceanography condition, and to determine a concept of fisheries management of the Bone Bay. Data were obtained from fishing activities conducted by local fishermen from January to December 2007, local fisheries statistics and internet-published data of sea surface temperature (SST) and chlorophyll (Chl) content. Seasonal and annual total fishing effort and fish production for a period of 11 years (1996-2006) were analyzed. Seven statistical parameters of the factors for SST and Chl were calculated and correlated with the fisheries statistics. The b coefficients for length-weight relationship in the three zones were equal to 3. The average fork-length (FL) of the fish in each zone showed similar trends, i.e it increased from January to June, then stabilized until December. Using von Bertalanffy’s growth model, the maximum FL (i.e.,76 cm) will be reached when fish at age of 84 months while the length at first maturity of the fish is 46,5 cm (FL). Overall, the average size of the skipjack tuna caught by pole and liners in January-April are small (31,5-46,3 cm, FL), from May to June the fish is larger (48,5-56,6 cm, FL), then the average size become smaller from July to December (33,7-48,2 cm, FL). From January to May, the size of the fish in the North Zone is generally smaller than in the two other zones. From May to August, the size of the fish in the South Zone is generally larger than in the two other zones. From September to December the size of the fish is generally similar among the three zones, but smaller than the size of the fish caught in the South Zone in June. Regardless of fish size composition, the MSYSS of Bay-wide shared fish stock is 15.783 tons/year with Fopt is 12.626 trips/year. However, considering length at first maturity of the species, the catch allocation for the North Zone should be 573 tons/year with fishing effort of 409 trips/year, catch in the Center Zone should be 5.820 tons/year with fishing effort of 3.279 trips/year, while in the South Zone should be 2.210 tons with fishing effort of 1.688 trips/year. The relationship between fish production and SST/Chl, for both seasonal and quarterly in the North, Central and South Zones were categorized as type 11, 10 and 5, respectively. Significant correlations were identified between SST/Chl and production of skipjack tuna in each zone, but the relationship between SST/Chl and fishing productivity of skipjack tuna is significant only in the Center Zone. These biological features and dynamics suggest that the North Zone should be prioritized for protecting skipjack juveniles. The fishermen in the North Zone should be given some incentives to support the conservation by alternative livelihoods and allocation of some benefits generated by the fisheries in the Central and South Zone.

Pengelolaan perikanan seyogianya mencegah terjadinya masalah penangkapan berlebih atau overfishing yang saat ini sudah terjadi di berbagai perikanan dunia, terrmasuk Indonesia. Salah satu langkah awal untuk mengelolanya adalah diketahuinya informasi yang cukup tentang karakteristik sumber daya ikan yang ditangkap dan kondisi lingkungannya dalam rangka menentukan strategi pengelolaan setepat mungkin. Perikanan Indonesia berlangsung di perairan yang luas sehingga memerlukan pendekatan tertentu agar pengelolaan perikanan dapat dilaksanakan secara efisien dan efektif. Salah satu pendekatan di antaranya adalah dengan cara membagi perairan Indonesia menjadi sejumlah kawasan pengelolaan perikanan. Saat ini di Indonesia terdapat sebelas Wilayah Pengelolaan Perikanan (WPP), sebagai bentuk pengelolaan dengan pendekatan pengaturan spasial (zoning) yang lebih menitik-beratkan pada aspek geografi kegiatan penangkapan ikan dan aspek administrasi dari tempat-tempat pendaratan ikan. Namun pembagian wilayah tersebut tidak serta merta membuat pengelolaan mudah dilakukan (efisien) dan efektif mengingat kondisi ekologi dan karakteristik perikanan sangat beragam, meskipun pada WPPI yang sama. Oleh karena itu, pengelolaan yang berbasis kondisi lokal perlu dikembangkan dengan zoning pada wilayah geografi yang lebih sempit, misalnya pengelolaan perikanan berbasis teluk.