Rich diversity, strong endemism, but poor protection: addressing the neglect of sandy beach ecosystems in coastal conservation planning

Abstract

AbstractAimSpatially‐explicit trends in species richness and endemism on sandy shores are quantified to assess representation of beach ecosystems in existing reserve networks. Also, the relative importance of different drivers of species distributions are compared through species distribution modelling.LocationThe South African beaches are among the best‐studied in the world, providing sufficient biological data for the analyses. There is also a well‐established coastal protected‐area network that putatively provides moderate protection to nearly all beach habitats.MethodsSpecies distribution maps of beach‐dependent vertebrates, macrofauna, microflora, and foredune vegetation were compiled from existing sources or modelled using standard techniques. While some data were available for the latter analyses, additional sampling was required to improve bioregional coverage. Each species' distribution was coded to a detailed map of the South African shoreline. Representation of habitats and species in various configurations of existing reserves was determined.ResultsOverall, 535 species have been recorded on the South African sandy shores, including 139 common species. Endemism is variable among taxonomic groups. Notably, two‐thirds of the macrofauna are regional endemics, half of which are endemic to South Africa. For almost all of the common species, < 20 % of their distributions are protected in land‐sea reserves. Protection of beach habitats is similarly poor; conservation targets were not met in all cases, and most habitat types are considered Poorly Protected.Main conclusionsSandy beach communities are considerably more diverse than they are generally acknowledged to be, and comprise a unique suite of biota. Given the species' narrow distributions and high degree of exposure to threats, many probably qualify as threatened/endangered. In spite of this, beaches are poorly represented in coastal reserve networks. To redress this issue, conservation planners need to account for beaches specifically, and to ensure they are represented in contiguous land‐sea protected areas.