Assessing the Potential to Extrapolate Genetic-Based Restoration Strategies Between Ecologically Similar but Geographically Separate Locations of the Foundation Species Vallisneria americana Michx

Restoration of genetic diversity to levels that ensure long-term species persistence is an important management strategy in degraded systems. Unfortunately, genetic data are lacking for many species such that practitioners must make management decisions for data-deficient areas using information from other parts of a species’ range. For such a management approach to be reliable, genetic diversity needs to be structured similarly. To determine if this is the case, we compared genetic structure in the submersed aquatic plant species Vallisneria americana across similar salinity gradients in three major tidal rivers in eastern North America (the Potomac, Hudson, and Kennebec) using 10 microsatellite markers. The Potomac supported high genotypic diversity, and no barriers between sampled sites were identified. Migrant analysis suggested that moving restoration stock within 22 km would fall within natural dispersal distances and thus create low risks, if augmentation were sought for sites where potential inbreeding was detected. The Hudson supported low genotypic diversity. No inbreeding was detected in the Kennebec or the Hudson, but dispersal barriers and recent bottlenecks were observed. These differences in genetic structure among rivers could limit broad adoption of management guidelines based solely on genetic data from one part of this species’ range. Such guidelines could risk moving restoration stock across barriers in the unsampled rivers, altering the species’ genetic architectures and potentially its natural resilience. Despite the allure of applying science-based generalities to restoration practice, locally relevant data and stock may often be needed for restoration efforts to maintain self-sustaining systems.