Benefits of genetic data for spatial conservation planning in coastal habitats

Abstract

Coastal marine environments are subject to a variety of anthropogenic pressures that can negatively impact habitats and the biodiversity they harbor. Conservation actions such as marine protected areas, marine reserves, and other effective area-based conservation measures, are pivotal tools for protecting coastal biodiversity. However, to be effective, conservation area networks must be planned through a systematic conservation planning (SCP) approach. Recently, such approaches have begun to orient their goals toward the conservation of different biodiversity facets and to integrate different types of data. In this review, we illustrate how genetic data and molecular techniques can bring useful knowledge for SCP approaches that are both more comprehensive (sampling the full range of biodiversity) and more adequate (ensuring the long-term persistence of biodiversity). With an emphasis on coastal organisms and habitats, we focus on phylogenetic analysis, the estimation of neutral and adaptive intraspecific genetic diversity at different spatial levels (alpha, beta, and gamma), the study of connectivity and dispersal, and the information obtainable from environmental DNA techniques. For each of these applications, we discuss the benefits of its integration into SCP for coastal systems, its strengths and weaknesses, and the aspects yet to be developed. Impact statementGenetic data provide useful information to guide the siting and design of conservation areas in coastal systems, such as marine protected areas. For example, reconstructing the evolutionary relationships between species through a genetic-based phylogenetic tree can inform on the presence of evolutionarily distinct species and orient the creation of marine protected areas toward sites where these species are present. Another useful application of genetic data is parentage analysis, where juveniles can be assigned to their parents and the distance between them can be used to infer the dispersal capacities of these individuals in the larval stage. These data, in turn, can be used to define the spacing between different marine protected areas, so that larvae can disperse between them while minimizing the risk of being transported to areas open to fishing. We review how applications of genetic data (including phylogenetic inference, study of intraspecific genetic variation, estimation of dispersal, and sequencing of environmental DNA) can be fruitfully used to plan networks of marine conservation areas that are more effective, meaning that they protect all facets of biodiversity in the long term. The integration of genetic data into marine spatial conservation planning can thus help reach global goals of biodiversity conservation.