Building an expert judgment-based model of mangrove fisheries

Abstract

Mangroves are critically important habitats for fisheries, both for their resident fish, crustacean, and mollusk populations and as nursery grounds for the target species of offshore fisheries. However, the spatial variation in the benefits provided by mangroves to fisheries is poorly understood. Based on expert knowledge of mangrove ecology and fisheries biology, we developed a preliminary model of the spatial distribution of benefits to fisheries from mangroves. The preliminary model covers the environmental factors that determine the amount of fish, crustaceans, mollusks, and other fishery target species produced by mangrove areas (termed “potential fish production”) and the socioeconomic variables that determine the level of fishing in any given location. The combination of these two outputs gives the predicted catch. Potential fish production is predicted to be highest where there is high freshwater and nutrient input to mangroves, such as in large estuaries. At large seascape scales, total mangrove area is also an important driver. Fishing effort is highest close to human populations, which provide both the fishers and the markets for their catch. The model is qualitative and has not been parameterized with field data and, as such, should only be considered as a first step towards understanding the spatial variation in the benefits that mangroves provide to fisheries.