Sea level rise has accelerated during recent decades, exceeding rates recorded during the previous two millennia1. Many coastal habitats and species around the globe are vanishing2. This situation is expected to worsen due to anthropogenically induced climate change. However, the magnitude and relevance of expected increase in sea level rise (SLR) for marine and terrestrial species reliant on coastal habitat for foraging, resting or breeding is unknown. We combined freely available digital elevation models for continental and remote island beaches across ocean basins with field data and sea level rise projections to explore the potential impact of SLR under various IPCC SLR scenarios on sea turtle nesting habitats at some of the largest rookeries worldwide. The study sites host five out of seven living species and all of them are categorized from vulnerable to critically endangered3 and essential due to sea turtles return to natal beaches to nest4. Our results confirm that the majority of sea turtle nesting habitat could vanish within the next few decades, leading to the depletion of many populations worldwide. Thus, even under moderate climate change scenarios, a large proportion of sea turtle nesting habitat will be flooded by 2050 and not survive to the end of the century. Overall, nesting populations with a low steep beaches slope and those species nesting at open beaches such as leatherback and loggerheads sea turtles might be the most affected under future SLR scenarios.

Animal seed dispersers may influence plant genetic diversity, though there are few examples linking disperser behavior to population genomic diversity. We hypothesized that breeding colonies of the frugivorous White-Crowned Pigeon (Patagioenas leucocephala) would increase population diversity and decrease population differentiation in fruit trees at nesting sites due to increased seed dispersal from foraging trips. We measured the density and extent of colonies at Parque Nacional Jaragua (Dominican Republic) and used nuclear and plastid SNPs from ddRADseq to examine the spatial genetic structure of two common species: poisonwood (Metopium toxiferum), a key fruit resource during the breeding season, and gumbo limbo (Bursera simaruba). We found that pigeon nesting aggregations in and around Parque Nacional Jaragua occupy areas between 3 and 5 Km2, with an estimated number of active nests for 2016 extrapolated to 3 km2 of 159,144  21,484 s.e., making this one of the largest breeding aggregations for the species across its range. However, colony locations did not determine tree genetic diversity and differentiation. Gumbo limbo (consumed by a diverse community) showed less isolation by distance than poisonwood. Saplings and plastid markers, expected to be more strongly influenced by seed dispersal, did not display geographic structure associated with colony sites, suggesting that patterns were not primarily due to pigeon foraging. Our results highlight the diversity of population genomic patterns among co-occurring species with similar ecological niches and demonstrate the limitations for frugivores to influence genetic differences among plant species.