Relationship between mangrove abundance and tropical prawn production: a re-evaluation

Despite decades of research, the relationship between mangrove abundance and fishery productivity in nearshore environments is still controversial. A new analysis was made to explore the relationship between prawn catch in 1985–2001 in 37 countries and mangrove abundance, using the principal components–regression approach. Principal components reduced mangrove abundance and other predictor variables (latitude, tidal amplitude, coastline length, population size, rainfall, and temperature) to four orthogonal principal components, accounting for 78% of the overall data variation. Representation of mangrove abundance in both absolute (total area of mangroves) and relative (mangrove area standardized against length of coastline) terms also helps elucidate the effect of mangrove abundance on prawn catch. Regression analysis with prawn catch using these four principal components suggests that the extent of intertidal areas and organic matter availability as represented by tidal amplitude rather than relative mangrove abundance per se have a stronger influence on prawn catch in tropical nearshore environments. This approach avoids some of the common problems of past analyses, such as multi-collinearity of the predictor variables.Communicated by G.F. Humphrey, Sydney