Towards sustainable artisanal fisheries for the common pool resource Spondylus (Bivalvia, Spondylidae) in Ecuador

Abstract

The artisanal fishery for Spondylus has a very long tradition in Ecuador but developments in recent years have made it an excellent example of the rapid overharvesting of a Latin American shellfish fishery. In reaction to the declining population status, the Ecuadorian government enacted an official ban on the fishery in October 2009. The ban is intended to be kept in place at least until there is scientific information regarding stock status and basic population parameters that are necessary for a sustainable use of the resource. This study aims to provide the necessary knowledge base to develop a sustainable management program for Ecuadorian Spondylus stocks in the future. Our findings suggest that current population densities will not allow for a recovery without additional measures to support such recuperation. Nevertheless, the parameters we have calculated for growth and fecundity suggest that exploitation of Spondylus as a resource is generally possible when undertaken with caution. Under a precautionary approach it is crucial for a future management program to monitor densities of individuals closely, as this study identified recruitment failure as the main factor that has contributed to the collapse of the fishery in the past. Restoration efforts would be of high value for the local ecosystem as this study has also shown that Spondylus contributes significantly to the native biodiversity. Their shells provide a three dimensional habitat for a variety of drilling and non-drilling species that are not present without them, thus making Spondylus an important foundational species. Artisanal fisheries make a significant contribution to satisfying the increasing global demand for protein. It is dangerous to assume, that these fisheries operate sustainably per se and it is crucial to ensure that they do in the future. Sustainable solutions for artisanal overfishing are urgently needed, because tropical coastal communities are highly dependent on their local resources for their livelihoods and nutrition. The tools for successfully managing a common pool resource such as Spondylus through a co-management system are known we hope these are used in the future in conjunction with the findings of this study to prevent this iconic genus from disappearing.