Extending biodiversity conservation with functional and evolutionary diversity: a case study of South African sparid fishes

Designing marine protected area (MPA) networks has relied primarily on species- or habitat-based measures that assess spatial distributions of biodiversity. Molecular and functional data have the potential to unlock information regarding the evolutionary uniqueness and resilience of natural communities, making phylogenetic diversity (PD) and functional diversity (FD) effective tools for spatial planning. These are, however, rarely used in marine conservation planning. In South Africa, MPAs have been implemented to protect rare and valuable fishery resources, such as members of the Sparidae (seabreams), but have not considered different dimensions of biodiversity, such as its phylogenetic and functional components. Here, we mapped species distributions, phylogenetic relationships and functional features of the Sparidae in South Africa to refine how biodiversity is spatially structured for this species-rich taxonomic group. Our results show strong spatial similarities between PD and FD, suggesting that, for this group, PD is an effective surrogate for functional data. However, there was a mismatch between areas selected with different biodiversity metrics (particularly endemicity levels) and established MPAs, highlighting the need for integrated approaches to conserve this unique marine fauna.