Bioeconomics of the Allee effect in fisheries targeting sedentary resources

The improvement of survival in some species due to the close coexistence between individuals is a concept that has caught the attention of scientists over the years. This behaviour has been documented in many taxa, including species which support commercial fisheries. In recent years, a better understanding of the mechanisms associated with the Allee effect has shown its importance in population dynamics and probably plays a more important role than previously thought. In this article, the Allee effect was analysed by means of a spatial bioeconomic model. The Allee effect component was the positive relationship between the mating probability and the density of spawners. A depensation function with an offset to the right side of the origin represented the fraction of females that mated based on density. When the model did not include the Allee effect, the fishery reached the bioeconomic equilibrium; however, when the Allee effect was considered, the fishery did not reach equilibrium, but the stock collapsed in 15 years. Fishing mortality altered the spatial distribution of the stock, causing depensation in recruits per spawner. These results may contribute to a better understanding of the Allee effect on sedentary resources and can be used to explore new models.