Improving Utilization of the Queen Conch (Aliger gigas) Resource in Colombia

A bioeconomic model was developed to investigate optimal exploitation strategies for the queen conch (Aliger gigas) resource in the Colombian Caribbean. Ecological and economic indicators substantially improved when the status quo management system based on sustained annual harvesting of the resource at a rate of 8% of the total exploitable biomass was replaced with a rotational harvesting scheme whereby fishing was conducted at a higher exploitation rate (30%), following a four-year closure period. Closures allowed queen conch biomass to recover and accumulate undisturbed, leading to an 11% increase in the average standing density of adult conchs and a 26% increase in the net present value of the fishery, as compared with the status quo scenario. Multiple sources of improvement associated with rotation of fishing areas were identified, such as the harvesting of larger quantities of conch meats and pearls as well as reduced fishing costs. In addition to an informed assessment of the economic potential of the fishery under rotational management, the model provides a useful benchmark to estimate the gains associated with further reductions in illegal, unreported, and unregulated fishing, which has brought the fishery to the brink of collapse in recent years.