TIPE PERIKANAN DAN STATUS SUMBERDAYA IKAN TERUBUK (Tenualosa macrura, Bleeker 1852), DI PERAIRAN ESTUARIN BENGKALIS DAN SELAT PANJANG

Abstract

Ikan terubuk (Tenualosa spp.) adalah ikan estuarin bersifat ‘protandrous hermaphrodite’ dan endemik di estuarin sekitar Bengkalis. Jenis Tenualosa macrura ditemukan di sekitar Bengkalis (Riau), jenis T. ilisha di sekitar Labuhan Batu dan Labuhan Bilik (Sumatra Utara), sedangkan T. toli ditemukan di perairan pantai barat Pemangkat (Kalbar). Sumber daya terubuk di sekitar Bengkalis saat ini sangat menurun akibat eksploitasi dan recruitment overfishing meskipun pembatasan penangkapan telah diterapkan. Tulisan ini membahas status sumber daya ikan terubuk di sekitar Bengkalis dan Selat Panjang berdasarkan data monitoring hasil tangkapan periode 2014-2016 dan observasi lapangan selama 2015-2016. Ikan terubuk merupakan ikan dominan dari enam jenis hasil tangkapan pada gill net, jumlahnya sekitar 15% dari total hasil tangkapan, upaya penangkapan tergolong intensif sehingga penurunan upaya yang dilakukan ternyata kurang signifikan, bahkan pada saat close season dan close area (September sampai November) upaya penangkapan cenderung tinggi. Kondisi ini tentu tidak sesuai dengan tujuan perlindungan terbatas dan konservasi jenis yang diterapkan. Penurunan populasi terubuk tampak nyata dalam bentuk hasil tangkapan (CPUE), sex ratio maupun produksi pendaratan. Ikan kategori “Pias” (ikan jantan) tetap dominan dan semakin banyak, sebaliknya kategori “Terubuk” (ikan betina matang gonad) semakin sedikit, artinya ukuran rata-rata ikan juga semakin kecil. Keberadaan populasi ikan terubuk di sekitar P. Tiga (Kab. Kepulauan Meranti) dengan kondisi matang gonad dan secara genetik memiliki pola DNA yang sama dengan yang berada di Bengkalis. Perluasan daerah konservasi dan perlindungan terbatas terhadap stok-stok tersebut disarankan.

The terubuk (Tenualosa spp) or shads, is a estuarine and endemic ‘protandrous hermaphrodite’ fish species. Species Tenualosa macrura is found in estuarine waters around Bengkalis (Riau Province), T. ilisha around Labuhan Batu and Labuhan Bilik (North Sumatera Province) while T. toli in west coast of Pemangkat (West Kalimantan Province). The terubuk reosurce in Bengkalis water is heavily degraded due to high exploitation and recruitment overfishing eventhough fishing limitation is applied. This paper is discussing the status of terubuk/longtail shad (Tenualosa macrura) resources in Bengkalis estuarine and Selat Panjang waters (Kabupaten Kepulauan Meranti) base on data of 2014-2016 catch monitoring data and field observation during 2015-2016. Terubuk is one of 6 dominant catches from gillnet, contributing about 15% of all catch. The fishing effort was so intensive even though management measure is applied to reduce its exploitation. During the close season when fishing on terubuk is banned (in September to November) as well as the ban in close area , the fishing effort has been still high. This condition is not in line with the objective of protecting the terubuk resources. Therefore, this condition must be changed and returned to objective of “limited protection” and “species conservation” by adopting a more strict rule on limiting fishing effort on terubuk through an evaluation. The decreasing of terubuk population can be seen from CPUE, sex ratio and also in landing, short time (2012 – 2016) and long time (18 years). In overall, the “Pias” (adult male) individuals remainned dominant and wereeven getting more in number, while the “Terubuk” (adult female) on the contrary, which means that the average size of actual fish cought was getting smaller. The existence of terubuk population around Pulau Tiga (Kabupaten Kepulauan Meranti) with mature gonad would share the same genetic pattern with population from Bengkalis. This explaines the connectivity between two stocks, at least there might be another spawning stock other than Bengkalis’s. The expand of the conservation area and limited protection on those stocks is highly recommended.