Changes in Fishing Pattern From Surface to Deep Longline Fishing by the Indonesian Vessels Operating in the Indian Ocean

Abstract

(P.T. Perikanan Samodra Besar) data are a valuable source, since they are the longest time series of catch and effort data available from the fishery. This paper aimed to interpret the spatial and temporal catch and effort trends to the extent possible and to reconcile apparent changes in targeting practices against the actual catch. Catch and effort data collected by P.T. Perikanan Samodra Besar from its Benoa-based longliners during 1978-1995 were summed to obtain annual catch, effort, and catch per unit of effort trends. To generate spatial distributions of catch and effort, catch and effort data were aggregated by 5-degree squares. The data showed that P.T. Perikanan Samodra Besar vessels commenced deep longlining in 1983, i.e. 56% of the total sets in 1983 using 10 or more hooks between floats. Prior to that, P.T. Perikanan Samodra Besar vessels used 6 hooks between floats,which resulted in a larger amount of yellowfin tuna (Thunnus albacares) as well as overall tuna catch. However, bigeye tuna (Thunnus obsesus) catch per unit of effort only increased from 1992. The increase in big eye tuna catch per unit of effort coincided with a reduced fishing range and concentration within an area where P.T. Perikanan Samodra Besar had not previously experienced high big eye tuna catches, as opposed to focusing their effort on areas where they had historically caught big eye tuna. In the absence of supplementary information, and assuming that the switch to deep longlining in 1983 was done to target big eye tuna, the analysis suggests that the outcome of P.T. Perikanan Samodra Besar fishing activities between 1983 and 1991 were inconsistent with their objectives.

Comparison of Indonesian Tuna Longline Fishing Performance Within and Outside Indonesia Exclusive Economic Zone (Eez)

“…The low catches within the EEZ for BET, ALB and SBT seem to have related to the use of deep longline gear configuration since 1983, which targeting BET rather than YFT (Sadiyah et al, 2011a). Most of the YFT caught when the fishermen using shallow longline configuration (between 5-7 hooks between float).…”

“…Gafa et al (2000, Eddrisea et al (2008) and Sadiyah et al (2011b) had extended the analysis of the catch data from the same company for the years 1978-1995. Furthermore, on the basis of analysis of scientific observer data of 2005-2007, Sadiyah et al (2011a recommended the need for hook rate standardization owing to the varied size of fishing vessel used. Meanwhile no attempt has been made to separate catch on the basis of two big fishing zones, namely the EEZ and the high seas.…”

BEBERAPA PARAMETER POPULASI IKAN PEDANG (Xiphias gladius) DI SAMUDERA HINDIA BAGIAN TIMUR

“…Ikan pedang (Xiphias gladius) merupakan satu-satunya spesies dari famili Xiphiidae dan telah menjadi obyek eksploitasi di Samudera Pasifik (Brodziak & Ishimura, 2010), Atlantik, dan Laut Mediterania (Tserpes & Tsimenides, 1995). Di Samudera Hindia, eksploitasi ikan pedang, dimulai sejak tahun 1950-an oleh armada Jepang dan didominasi oleh armada Taiwan pada tahun 1990-an (IOTC, 2009) sedangkan Indonesia mulai pada tahun 1983 semenjak diperkenalkannya deep tuna longline (Sadiyah et al, 2011). Hasil tangkapan ikan pedang di Samudera Hindia terus meningkat, sekitar 10.000 ton pada awal tahun 1990 dan mencapai puncaknya pada tahun 1998, yakni sekitar 35.000 ton (Wang & Nishida, 2010).…”

Pengaruh Anomali Iklim (Enso Dan Iod) Terhadap Sebaran Ikan Pedang (Xiphias Gladius) Di Samudera Hindia Bagian Timur

“…Di Samudera Hindia, ikan ini dieksploitasi mulai 1950an oleh armada Jepang dan didominasi oleh armada Taiwan tahun 1990-an (IOTC, 2009. Sedangkan nelayan Indonesia baru mulai memanfaatkannya pada 1983 semenjak diperkenalkannya deep tuna longline (Sadiyah et al, 2011).…”

“…Perikanan Samudera Besar (sekarang menjadi PT. Perikanan Nusantara) (Sadiyah et al, 2011). Setelah masuknya armada Taiwan dan Jepang, kompetisi di daerah penangkapan tersebut menjadi sangat ketat.…”