A Review on Anchored Fish Aggregating Devices(Afads) As a Tool to Promote and Manage Artisanal Fisheries
Total Page:16
File Type:pdf, Size:1020Kb
水産工学 Fisheries Engineering 1 Vol. 56 No. 1,pp. 1〜13,2019 【Research Article】 A Review on Anchored Fish Aggregating Devices(aFADs) as a Tool to Promote and Manage Artisanal Fisheries Khyria Swaleh KARAMA1,2 and Yoshiki MATSUSHITA1,3* Abstract Fish Aggregation Devices(FADs) are simply man-made, floating devices, which make use of the natural habit by aggregating pelagic fishes for subsistence, recreational and commercial fishing. The introduction of anchored FADs(aFADs) has mainly been promoted throughout the world to assist small- scale fisheries. This paper details information of East Asia and Indian Ocean regions where aFADs are heavily, traditionary used or successfully implemented. We focused on the aFAD design, fishing gear used, target species and others. In addition, we highlighted the issues and management measures related to aFADs. The main aim was to give supplementary information since aFADs are an important tool for promoting, managing artisanal and small-scale commercial fisheries all over the world, increasing localized catches at reduced costs thereby improving food security and livelihoods of the coastal communities. world6)-12). While there is a concern that FADs may 1. Introduction modify both fish movement and condition for pelagic It has been known for a long time that floating objects fish such as tuna species, which has been hypothesized aggregate fish1),2). It depends on the fish species and as a significant ecosystem impact12)-15). the surrounding environments. But they are known to The first type of FADs used is drifting FADs provide refuge from predators, a meeting place for (dFADs) that drift freely with the currents and are schooling companions, a place for orientation, a substrate deployed for exclusive use of the boat or fleet that set for species undergoing a change from pelagic to other them afloats16). They are deployed in both EEZ and modes of existence, a feeding place or that they high seas areas with the aim of increasing the efficiency duplicate natural aggregators such as sargassum of the high volume purse seine fishing. This phenomenon seaweed2)-5). We have been utilizing these facts to has been exploited by fishers to augment their catch, catch fish efficiently around floating devices. and, over the past few decades, dFADs have grown to Fish Aggregation Devices, or FADs are simply man- be the key component of tropical pelagic fisheries made, floating devices, which make use of the natural including tuna industrial fishing fleets17)-19). The dFAD habit by aggregating pelagic fishes for subsistence, related purse seining is nowadays a technologically recreational and commercial fishing. The use of FADs advanced fishery that yields over half of the worldwide has increased, this has reduced the uncertainty of recorded tuna landings20)-22). However, dFADs has finding fish and has generated new opportunities with raised concerns regarding adverse effects on migratory greater reliability in all oceanic areas. The success of patterns23),24),school composition status25), growth26), FADs in aggregating fish has made these devices predation rates27) and juvenile catches22). Because of important to the commercial, local and sports fisheries these concerns and economic importance, dFADs are of many tropical, sub-tropical seas and oceans in the frequently studied and reviewed lately18),19),22), 28). Received November 2, 2018 Accepted January 17, 2019 Key words:anchored Fish Aggregating Devices(aFADs),artisanal fisheries, pelagic fish, review 1 Graduate School of Fisheries and Environmental Sciences, Nagasaki University, 1-14 Bunkyomachi, Nagasaki 852- 8521 Japan 2 Kenya Marine and Fisheries Research Institute, P.O. Box 81651-80100, Mombasa, Kenya 3 Organization for Marine Science and Technology, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521 Japan * Tel:095-819-2803,Fax:095-819-2803,[email protected] 2 Fisheries Engineering Vol. 56 No. 1 The second type of FADs is known as anchored heavily deployed. In this paper, we focus on the aFADs FADs(aFADs, also referred to as moored FADs). The design, fishing gears used, target species and others in role of aFADs in fisheries and in the regions is different the above mentioned regions. In addition, we highlighted from dFADs. Unlike dFADs for commercial purse seine the issues and management measures related to aFADs. fisheries, the introduction of aFADs has mainly been The main aim was to give supplementary information promoted throughout the world to assist small-scale since aFADs are an important tool for promoting and fisheries29). The aFADs were first used in the Philippines managing artisanal and small-scale commercial fisheries before World War II to support small-scale fisheries30). all over the world, increasing localized catches at Its use was documented in the Mediterranean and was reduced costs and thereby improving food security and first introduced into the Pacific from the Philippines, via livelihoods for coastal communities. Hawaii, in the late 1970s with a high rate of success: in 2.Examples of major countries implementing 1984 more than 600 aFADs were deployed in the aFADs western and central Pacific Ocean region31). The aFADs are used extensively by many countries32),in the Pacific18 Use of FADs is confirmed in 37 countries and regions ),33),34) Indian35) and Atlantic oceans36),37). in Atlantic Ocean, 33 in Pacific Ocean, 18 in Indian In general, aFADs are mainly placed in coastal and Ocean and 8 in the Mediterranean Sea according to offshore zones, at depths from less than 100 m38) up to Taquet41). These numbers are many and probably 5000 m39) in order to attract pelagic species including cover most countries that deploy aFADs, but tunas. Construction and sizes vary from small scale geographical coverage would be inevitably biased traditional types made from natural materials to large depending on author’s base. In case of the review by scale modern types made from steels and/or plastics. Taquet41), FADs in Atlantic Ocean was reported in They are frequently used to provide enhanced detail, but in Pacific, eastern Asian countries such as opportunity for artisanal and semi-industrial fishers and South Korea or Taiwan, which are strong users of both are usually fished using several techniques, such as aFADs and dFADs were not covered. Accordingly, we trolling, pole and line, traps, vertical long-line, handline, present aFADs information for the following 5 countries ringnet and sometimes purse-seine. depending on the available information. In the industrial sector, private investors fund the 1) The Philippines deployment and monitoring of their own aFADs. These There is a wide variety of types and designs of industrial aFADs are used extensively in countries like aFADs used in the Philippines made of natural and Indonesia, Papua New Guinea, the Philippines, Thailand, modern materials including brush pile, twigs, bamboo, Federated States of Micronesia and the Solomon scrap tires, concrete and steel. The most popular type Islands31). In small-scale fisheries, aFADs are almost that emerged as the most economical and effective in exclusively maintained and deployed by the public terms of resource management and income enhancement sector and overseas funding agencies31,40). Many aFAD for fishers i.e. the bamboo raft aFADs called “payao”. settlement programs are designed as a small-scale The use of payaos is widespread where thousands are fishery management approach to relieve the frequently anchored throughout to support subsistence, artisanal heavy fishing pressure being experienced by coastal and commercial fisheries45). There is no statistics on the species by transferring effort toward pelagic species, total number of payaos all over Philippines, but it was including tunas. These programs are thought to provide estimated that there were about 3000 payaos in Moro Gulf many positive benefits for local fisheries16). in the southern Philippines. Some payao fishing grounds This paper further details some countries where aFADs are also found in the other parts of the archipelagic were traditionary used or successfully implemented. waters whereby established viable tuna and small Reviews or technical guidelines for aFADs14),41) have pelagic fisheries exist45). Generally, payaos are crowded been published other than this paper. However, they in the nearshore fishing grounds about 30 payaos discussed Southeast Asia, South Asia42),16) and South anchored for each boat. They used simple bundles of Pacific countries43),44),where the use of aFADs is bamboo provided on the underside with a hanging line popular31),but did not include information of Eastern of coconut leaves, later evolved into well-constructed Asia and Indian Ocean regions where aFADs are also double layer bamboo rafts with empty oil drums filled A Review on Anchored Fish Aggregating Devices(aFADs) as a Tool to Promote and Manage Artisanal Fisheries 3 with concrete used to anchor the payao. This type Indonesia. Rakit is a kind of small aFADs made of payaos are still commonly used in the coastal Philippine traditional materials and deployed in shallow waters waters, but steel longer lasting raft type payaos are (50-200 m) while rumpon is relatively large scale aFADs favored for use in exposed, offshore areas subject to set at waters ranging 400-4000 m deep47). They are used rough sea conditions( Fig. 1). particularly in the eastern Indonesia waters since time Payaos support several small-scale fisheries such as immemorial38),48). Rumpon is categorized by its handline fishery for tunas, purse seine and ringnet in deployment depth, while rakit sometimes referred to as the Philippines. Payaos are either owned by fishing shallow water rumpon in some reports38),49). Some fishers companies or leased by concessionaires to the fishing construct their rakit or rumpon in traditional manner companies for 20% of the price of the haul39). Payaos by coconut leaves and bamboo stems to catch small attract variety of species; the catches consist largely of pelagic fishes that looks similar to payaos in the juvenile tunas and small pelagic fish. In addition, 99% of Philippines.