Developing indicators to detect the use of fish-aggregating devices

Abstract

Context. The growing demand for global food security has resulted in rising fishing intensity, sometimes leading to overexploitation of fish resources, including tuna. Increasingly, fishers are using anchored fish aggregating devices (aFADs) to improve efficiencies and reduce costs. Aims. To identify locations and use patterns of FADs and characterise aFAD usage in Indonesia and beyond. Methods. We identified general patterns of aFAD usage by tuna purse-seine, pole and line, hand-line and troll-line vessels operating in Indonesian waters through reviewing relevant literature and focal-group discussions. Key results. aFADs usage can be characterised by gear type and fishing strategy; vessel behaviour; equipment and spare parts for aFADs installation; association with light; trip duration, catch per unit effort (CPUE), ratio of live bait to catch, fuel consumption; existence of aFAD floats on board vessels and by-catch composition. Conclusions. aFAD usage has been widely adopted by both industrial and small-scale tuna fishers to efficiency. However, this efficiency comes at the cost of significant increases in catches of juveniles and non-target species, which raises sustainability concerns for Indonesian officials. Implications. Ultimately, quantifying the numbers, types and locations of aFADs is key to fisheries management to avoid overfishing, overcrowding and limit by-catch and fishing-associated waste.