Risk aversion in allocating fishing effort in a highly uncertain coastal fishery for pelagic fish, Moluccas, Indonesia

The Ambonese small-scale purse-seine fishery for small pelagic fish, such as scads and mackerels, is characterised by highly variable daily catches. Fishermen involved in this fishery are therefore seriously constrained in optimising the outcome of their fishery through spatial allocation of effort. Spatial patterns in effort allocation were compared with those in catch per unit effort (CPUE), indexed by both catch weight and profit. Average CPUE indexed by catch weight differed between fishing locations by up to 14 times. However, individual fishermen could only detect such large differences after 14 days of exploratory fishing because of the high variability in daily catches. Daily decisions on effort allocation are therefore not based on maximising CPUE but on minimising operational costs and risk. A very high proportion (88%) of the fishing trips were made within 8 km of the home port, although the capacity of the purse seiners allowed for fishing in more productive areas much farther away. A 10- to 20-fold increase in operation costs (travelling and local use rights) when fishing in other areas reinforced this behaviour.