Shark Longline Fishery in Tanjungluar-East Lombok

Abstract

Studies on artisanal shark fisheries in Tanjungluar - East Lombok were conducted during the year 2001-2011 (except in 2003 and 2007). A sampling method called “rapid market survey” method was employed to collect catch data from surface and bottom longlines fishing, rapidly. Biological data and fisheries data were collected during survey. Catch data for shark were also obtained from daily records filled by TPI officers in Tanjungluar between 2009 and 2010. The results showed that shark<br />longline fishing was conducted every month. The trend of shark catches relates to the number of fishing vessels, fishing ground, and weather conditions at sea. The period between July and September is a transitional season from East to West seasons. During this season, the wind strength is weakened and a good fishing season for the fishers. The lowest catch occurs in January (1.06 tonnes) and the highest catch in September with the total catch of 24.6 tonnes. Sharks caught by surface longline were dominated by Silky shark, Carcharhinus falciformis (40-90%) with the size range of 100-125 cm. The catch of bottom longline was mostly consisting of fish in mature condition that dominated by Grey reef shark (<em>Carcharhinus amblyrhynchos</em>), Common black tip shark (<em>C. limbatus</em>), Spot tail shark (<em>C. sorrah</em>), and Scalloped hammerhead shark (<em>Sphyrna lewini</em>), with the size range of 125-200 cm, 170- 250 cm, 100-150 cm, and 170-300 cm, respectively. Surface longline fishing occurs in the offshore waters in depth more than 200 m to 3000 m, whereas bottom longline fishing is operated at a depth of 50-100 m around islands.

PARAMETER POPULASI HIU MARTIL (Sphyrna lewini Griffith & Smith, 1834) DI PERAIRAN SELATAN NUSA TENGGARA

“…Kelimpahan relatif hiu martil di perairan selatan Nusa Tenggara bervariasi diduga karena pengaruh makanan dan faktor oseanografi lainnya seperti arus dan turbulensi. Daerah yang memiliki potensi kelimpahan hiu martil tinggi akan cenderung dimanfaatkan secara terus menerus oleh nelayan (Dharmadi et al, 2013). Hal inilah yang terjadi di WPP 573 pada perairan NTB dan NTT.…”

Catch Composition and Some Biological Aspects of Sharks in Western Sumatera Waters of Indonesia

“…There were as substantial landings of C.falciformis and S. laticaudus (Fig.4), which are also common in the tropical Indo-West Pacific. Dharmadi et al (2013) reported that majority of C. falciformis caught in eastern Indian Ocean are immature (75,9 %) and only 24.1% are mature. The length frequency of the Silky sharks fluctuates between 50-250 cm, dominated by 100 cm individuals corresponding to immature individuals (Oshitani et al, 2003).…”

Catch and Relative Abundance of Some Sharks Landing in Tanjung in Luar, Lombok

“…Salah satunya adalah di Tanjung Luar, Lombok Timur yang merupakan salah satu basis perikanan hiu terbesar di provinsi Nusa Tenggara Barat. Di lokasi tersebut, hiu dan pari telah menjadi ikan target utama dengan alat tangkap utama adalah rawai (long line), baik dasar maupun permukaan (White et al 2012;Dharmadi et al 2013). Jenis hiu yang didaratkan di Tanjung Luar sebagian besar berasal dari nelayan setempat dan juga dari nelayan andon yang ingin mendaratkan dan memasarkan hasil tangkapan hiunya, baik sebagai target maupun sebagai hasil sampingan (Fahmi dan Dharmadi 2015).…”

“…Penelitian terkait perikanan hiu di Tanjung Luar relatif cukup banyak seperti yang telah dilaporkan oleh Widodo dan Widodo (2002), White et al (2012), Dharmadi et al (2013), Chodriyah (2014), dan Fahmi and Dharmadi (2015) serta beberapa publikasi lainnya. Publikasi terkait hasil tangkapan hiu dan sebaran kelimpahan relatif yang tertangkap oleh nelayan yang berbasis di Tanjung Luar perlu diperbarui datanya.…”

“…Penentuan kelimpahan atau kerapatan populasi hiu tidak selalu dapat dihitung secara pasti sehingga dalam hal ini dapat digunakan konsep sederhana berupa kelimpahan atau kerapatan relatif (Michael 1994 Spesies hiu predominan (kelimpahan relatif > 10%) yang didaratkan di Tanjung Luar adalah C. falciformis (42,06%), P. glauca (10,45%), dan C. limbatus (10,31%). Kondisi tersebut relatif sama dengan hasil penelitian White et al (2012), Dharmadi et al (2013), dan Wildlife Conservation Society (2014) bahwa hiu kejen (C. falciformis) merupakan hasil tangkapan yang umum dan dominan di wilayah penangkapan nelayan yang berbasis di Tanjung Luar. Sebaran lokasi tangkap menyebar mulai dari selatan Lombok, Sumbawa, Sumba, Sabu Raijua, Flores sampai dengan Rote (Gambar 3).…”