NATIONAL TUNA FISHERY REPORT Taiwan Tuna Fisheries in the Western Pacific Ocean Background paper presented in the tenth meeting of the standing committee on Tuna and Billfish (Nadi, 16-18 June, 1997) Fisheries Data Division Overseas Fisheries Development Council of the Republic of China 19, Lane 113, Roosevelt Road Sec. 4, Taipei, Taiwan, ROC
Taiwan Tuna Fisheries in the Western Pacific Ocean Overseas Fisheries Development Council of the Republic of China 19, Lane 113, Roosevelt Road Sec. 4, Taipei, Taiwan, ROC Active Vessels and Total Production In 1995, there was 42 distant-water purse seiners and 56 distant-water tuna longliners operated in the Pacific Ocean, and around 1,350 fresh sashimi tuna longliners (20-100 GRT) operated in coastal and offshore waters of Taiwan, Pacific and Indian Oceans countries. Total catch of tunas, billfishes and sharks were 257,805 t, of which distant water fisheries accounted for 91%, coastal and offshore water fisheries accounted for 9% (Table 1). Catches of distant-water purse seiners and distant-water tuna longliners were all from the Pacific Ocean, but only 19% of the fresh sashimi tuna longline catches were made from the Pacific Ocean. Table 1. Estimated vessel number and catches of Taiwan's tuna fisheries in the Pacific waters in 1995 and 1996. Tuna fisheries 1995 1996 comparison Distjiit-watui pr.im.* scini PisLinl-waier tuna lonyline 1 rosh sashimi tuna longline* 1,664 vessels catches vessels catches vessels catches 42 67 174,716 23,001 63,340 42 56 1,350 179,440 17,183 61,182 0.00% -16.42% -18.87% 2.70% -25.29% -3.41% coastal and offshore** - 27,926 700 23,513 - -15.80% distant waters - 35,414 650 37,669-6.37% Pacific - 14,329 470 12,922 - -9.82% others - 21,085 300 24,747-17.37% Total 1,773 261,057 1,448 257,805-18.33% -1.25% *Estimated numbers of 1995 and 1996 are registered vessels and active vessels respectively. ** Include catches from coastal spear fishery -not estimated 1
Catches and Fishing Activities Distant-water purse seine fishery The operation of the distant-water purse seine fishery in Taiwan could be traced back to 1982 when it was first introduced and since then WCPO has been its most important fishing ground. The total catch in WCPO by the 42 distant-water purse seiners during 1996 was 179,440 t, comprising 161,407 t of skipjack, 17,389 t of yellowfin and 644 t of other fishes, with transshipment for canning made at Guam, Truk, Wewak, Yap and Kelvin etc. to Thailand, the United States, and Japan. Logbooks collected via Taiwan Deep Sea Tuna Boat Owners and Exporters Association to this Council is 100% with an average time lag of one and a half months after completion of each trip. According to the data complied from 1996 logbooks, a total of 6,214 fishing sets were made during 1996 with an average catch rate of 28.9 t per set. Fishing grounds were still mainly in PNG, FSM, high sea and adjacent waters (Figure 1), however, a conspicuous seasonal change was found. The phenomenon may mainly be caused by the reason that the fishing access in FSM waters was not renewed until September. Consequently, the fishing efforts during the first two quarters of 1996 distributed in Indonesia/PNG/high sea waters and northern/eastern PNG waters respectively. During July and September, fishing efforts were then concentrated in the waters adjacent to high sea, PNG and Indonesia waters. From September onward, fishing effort increased northward into FSM waters. Distant-water tuna longline fishery The Taiwan's distant-water tuna longline fleet in the Pacific Ocean comprises vessels of 46 conventional and 11 with super cold freezer. These vessels based out of Levuka, Fiji and Pago Pago, American Samoa and targetted albacore tuna for supply to the canneries located at these ports. Preliminarily, the total catches by the fleet for 1996 was 17,183 t comprising 15,244 t of albacore, 330 t of bigeye, 833 t of yellowfin and 776 t of other fishes. The time lags between logbook and landing report collection are always more than one year for this longline fishery. Therefore, the 5 X 5 aggregated effort and catch data for 1995 shown in Figure 2 are still preliminary. The nominal CPUE of distantwater tuna longline fishery in 1994 was 3.32 fish/100 hooks, but a preliminary value around 3 fish/100 hooks was estimated for 1995. The fishing ground in the South Pacific during 1995 was mainly around south of 0 S and west of 130 W (Figure 2). 2
Fresh sashimi tuna longline fishery In 1996, around 470 Taiwan's fresh sashimi tuna longliners (50-70 GRT) operated in the Pacific Oceans mostly based out of Philippines, Guam, Marshall Islands and Palau etc. The catches of these vessels were estimated to be about 12,9221, a decrease of 9.8% from the 1995 catch. Comparatively, catches from the coastal/offshore waters of Taiwan, Philippines and Indonesian waters, and the Indian Ocean waters were much more than those from the Pacific waters. Since the fishing activities fluctuated greatly comparing with those two other fisheries mentioned above, the rate of logbook coverage still in a low level. From the logbook available, a rough catch and effort distribution of fresh sashimi tuna longline fishery is presented in Figure 3. A preliminarily nominal CPUE of 2.48 fish/100 hooks was estimated from these fleets operating in the Pacific Ocean in 1996. Logbook collected from vessels operating in coastal/offshore waters of Marshall Islands were the main data source the atlases made from (Figure 3). Comparatively high fishing efforts were in the surrounding waters of Taiwan, South China Sea, Philippines and Marshall Islands waters. The most obvious differences in 1996 was that it showed nil fishing effort in FSM waters mainly due to the withdrawal of a major Taiwanese fishing company from this area since last year. A tremendous shortage of data from those vessels based in Guam and Philippines are noticed where 7,355 t and 1,900 t of landing were reported respectively. Filling the deficiency of these data is necessary for further study on the status of stock, and we would like to collect and exchange these data with the coastal fisheries agencies concerned through the current fisheries cooperation channels or arrangements available. Research Activities In order to strengthen the data collecting and processing work, OFDC set up a Fisheries Data Division to be in charge of this new responsibility. The job of the first year has been focused on the connection and reinforcement of the data collection system, and development of an independent data processing and management system. Monthly 5 X 5 aggregated catch and effort statistics of distant-water tuna longline fisheries in Pacific up to 1994 have been sent to SPC. Preliminary estimated 1996 landing data for distant-water tuna longline and distant-water purse seine were also provided. However, the collection of catch and effort data for fresh sashimi tuna longline fishery needs to be improved. The Taiwan Fisheries Bureau of Taiwan Provincial Government is going to insert more manpower and budget on collecting 3
such data in the new fiscal year. Beside our efforts, it is very important that the coastal states can provide assistance to us, where appropriate, to enable us to fulfill our responsibilities with regard to the collection of tuna fisheries data, which has been noted in the Report of the Technical Consultation on the Collection and Exchange of Fisheries Data, Tuna Research and Stock Assessment held last year. A sophisticate data processing and management system has being gradually established since last July. Presently, major part of this system has been developed and worked normally. The system integrates modules of data entry, correction, calibration, raising computation and compilation etc., which can improve the efficiency of statistics from different data sources. Besides, in the new fiscal year, this council is going to carry out biological sampling twice a month at Tung-Kang, a major domestic tuna fishing port in southern Taiwan. Size composition of yellowfin and bigeye tuna caught by coastal and offshore tuna longline fishery will be collected and prepared for the scientist participating in the tuna research project sponsored by the Council of Agriculture. 4
/ ffl Effort (number of set) 200 to 250 150 to 200 100 to 150 50 to 100 1 to 50» * c ^ t i» t Catch by Species (M/T) A 5,000 w 2,500 500 Skipjack Yellowfin Bigeyes Others Figure 1. Atlas of 1 X 1 aggregated logbook data showing the distribution of effort and catches for Taiwan's distant-water purse seine in 1996. 5
Catch by Species (1995) Unit: Kg 1,000,000 500,000 100,000 Albacore Bigeye Yellowfin Others Effort (1995) Unit: 100 hooks Figure 2. Atlas of 5 X 5 aggregated logbook data showing the distribution of effort and catches of Taiwan's distant-water tuna longline in 1995 (preliminary). Upper: catch in number; Lower: catch in weight.
Effort (1996) Unit: hooks 920,000 460,000 92,000 Catch by Species (1996) Unit: Kg 21,000 10,500 2,100 Bigeye Yellowfin Others Figure 3. Atlas of 5 X 5 aggregated logbook data showing the distribution of effort and catches of Taiwan's fresh sashimi tuna longline in 1996 (preliminary). Upper: effort; Lower: catch by species. 7