marine fisheries in Southeast Asia
Driftnetting has a long history in Southeast Asia, with the nets originally being made from coconut or ramie fibre imported from China. In areas such as the Straits of Malacca, Borneo, the Mollucas and Java, the landings from driftnets probably accounted for the majority of the catch in some areas during the nineteenth century. The traditional use of such nets were to set them in the evening and haul them in the morning with catches consisting of species such as shad, Spanish mackerel, wolf herring and small sharks, depending on the area fished and the mesh size of the net. The fishery in these early years was undertaken exclusively by small-scale fishers operating nets that were typically 110-400 m in length.
However, by the late 1920s, Japanese fishers based in Singapore had begun using driftnets in the Straits of Malacca and, by the early 1930s, there were two Japanese companies specializing in driftnetting there. These fishers undertook driftnetting on a much larger scale than the Malays and Chinese fishing in the Straits, using a 25 tonne vessel5 with a 50 horsepower engine to tow several smaller sail-powered fishing vessels from Singapore. Each of these smaller vessels operated nets that were some 900 m long and the catch was iced and returned to Singapore on a regular basis by a transport vessel. The fishing vessels therefore were able to stay fishing for long periods of time without returning to port. Catch rates were about 90 kg per vessel per day, compared with the Chinese and Malay vessels’ catches of about 9 kg per day. In 1932, the Japanese driftnetters landed 1400 tonnes of fish, mainly of Spanish mackerel, wolf herring, small sharks and shad, which comprised some 13 percent of total landings in Singapore.
By the end of the Second World War, the Japanese driftnetters, like other Japanese fishing fleets, no longer operated in the Straits of Malacca. However, their methods of using motorized vessels to tow smaller vessels to the fishing grounds and to transport the catch to market were soon adopted by local fishers. By the 1950s, outboard motors were becoming readily available and one of their first uses was to power existing craft that were used for driftnetting, particularly in the Straits of Malacca and the Malay Peninsula. The pace of mechanization of fishing vessels, and the impact that this had, cannot be overestimated - in 1947, about 1 percent of vessels in the Malay Peninsula were mechanized while by 1965, 55 percent of vessels had engines.
This increasing mechanization not only allowed catches to be transported from the fishing grounds to the market but also allowed vessels to follow fish schools, thus extending the area which was fished. At the same time, nylon nets began to replace the traditional fibre or cotton nets and, in 1958, it was noted that “drift net catches in the Malacca Straits have doubled with the replacement of cotton by synthetic fibre resulting in an increased supply of Tenggiri [Spanish mackerel] and Parang [wolf herring] to the west coast markets” (Anon, 1958).
In Indonesia, driftnetting for the same species as taken on the Malay Peninsula had also had a long history and the Japanese driftnetters based in Singapore in the 1930s also operated near the east coast of Sumatra within the Straits of Malacca. Indonesian fishers, however, continued to use small nets and sail-powered craft both on the east and west coast of Sumatra, Java and Borneo and the contribution to total catches from driftnetting remained small. In the 1950s, the number of vessels and fishers in Indonesia began to increase dramatically, from 80000 vessels in 1951 to 200000 in 1961, an increase of 120000. However , much of this increase was in non-motorised, traditional craft, which increased by 115000 vessels.
In contrast to the 55 percent of the fishing fleet in Malaya that was motorized by 1965, in Indonesia only 1.4 percent of the fleet was motorized by 1967 (Butcher, 2004, adapted from his table 6.6). Driftnet fishing in Indonesia, therefore, continued using traditional small nets and sail-powered craft, although the number of such craft evidently increased substantially during the 1950s and 1960s. When motorization of the fleet came to Indonesia in the late 1960s, it spurred the development of the trawl fishery (see Section III) but was adopted more slowly by other sectors such as the driftnet fishers. As a result, the importance of the driftnet fishery in Indonesia declined as a percentage of total landings as the landings from the trawl fishery increased rapidly.
After the trawl ban imposed by Indonesia in 1980 and 1981 in western parts of the country (see Section III), there was a rapid recovery in inshore demersal and pelagic fish stocks, despite the trawl ban being only partly effective. At the same time, the Government provided easy credit for the building of new vessels and imposed no restrictions on other forms of fishing, apart from trawling. This resulted in both an upgrading and mechanization of vessels (the number of motors about doubling during the early 1980s and the number of fishers increasing by a third) and an increase in both the number of motorized and non-motorised vessels. Although it is not known how the driftnet fishery was impacted by such changes, it seems reasonable to assume that driftnet fishers also took advantage of this situation to upgrade vessels and fishing gear so they could better target the increased abundance of fish in inshore waters.
In 1998, the number of fishing vessels in Indonesia had reached about 334000 (F AO, 2000) with 57 percent of them still without motors. Most of these were involved in small-scale traditional and subsistence fishing and, in 1998, this small-scale sector contributed 94.6 percent of total marine landings of 3.27 million tonnes (FAO, 2000, but total landings data apparently show a typographical error and therefore have been corrected in accordance with FAO, 2004). The purse seine fishery (17.64 percent), lift net fishery (8.26 percent), trammel net (5.02 percent) and the skipjack and yellowfin tuna pole-and-line fishery (3.08 percent) were the most important fisheries with driftnetting remaining a very minor component of overall landings.
Driftnet fishing also remains the preserve of small-scale fishers in most other countries of the region. In the Philippines, small-scale (or “Municipal”) fishers took about 922000 tonnes of fish in 2003 (Anon, 2005a), which represented about 45 percent of total landings. Although the most common fishing method used by these Municipal fisheries is hook and line, a fixed or floating gillnet contributed around 45.5 percent of total Municipal small pelagic landings in 1995 (Zaragosa et al., 2004). Small pelagic species are by far the most important component of the Municipal landings and these are also caught by other fishing methods (Zaragosa et al., 2004) such as hook-and-line (15.3 percent of total Municipal landings), ringnet (11.5 percent), beach seine (8.3 percent), purse seine (3.7 percent), fish corral (2.9 percent) and bag net (2.9 percent).
In Viet Nam, fixed and floating gillnets are also significant contributors to the landings from the inshore small-scale sector, with 18 percent of total landings in 2003 coming from these nets (FAO, 2005b). However, no distinction is made in the landings data between the types of net although at least some of these gillnets are operated as small driftnets. Drift gillnetting is, and always has been, more important in the northern parts of Viet Nam (including Ha Long Bay and the Gulf of Tonkin) than in the south although current statistical data (Anon, 2005b) does not allow the separation of landings and other data by fishing method.
5 The original report quoted by Butcher (2004) uses “tons” as a measure for vessel size and this presumably refers to displacement tonnage. No conversion to a standardized measure of vessel size is possible. See footnote 3 on issues relating to the measurement of vessel size.