Key gaps remain in the definition and application of keystone species concepts for fisheries management: A systematic scoping review

A keystone species is one whose influence is disproportionate to its abundance, the absence of which would change the dynamics of an ecological or human community. Despite its widespread use in the scientific literature, there is a limited understanding of how the keystone concept is defined or measured, or applied in practice, and especially in aquatic systems. This paper summarizes current uses and knowledge gaps associated with different approaches to applying keystone species concepts to fish and fisheries, based on a systematic scoping review of refereed literature published over the last decade. Cultural dimensions for keystone designation have not been applied to the same extent as ecological criteria. As well, only 13% of studies reviewed applied the term ‘keystone’ to a species by testing its status in the fish and fisheries domain. In general, ecological keystone species designation generally follows a systematic framework that involves using ecosystem dynamic modelling. We recommend that keystone species designation should be explicitly described and defined and should ideally incorporate both social and ecological dimensions of an ecosystem. From a socioeconomic perspective, inclusion of economic, sustenance and historical dimensions as well as cultural significance would provide a more robust application of the keystone species concept. Read the free Plain Language Summary for this article on the Journal blog.