Deep-sea biodiversity at the extremes of the Salas y Gómez and Nazca ridges with implications for conservation

providing neighboring areas with different ecological niches, which helps explain the high dis- similarity of invertebrate assemblages within and between seamounts of a region [88]. In our study, crust age was highly correlated with region, as the seamounts become progressively older moving eastward along the ridges from 2 million years on the western portion of the chain to over 27 million years towards the northeastern end [60, 89]. An endemism and biodiversity hotspot The nearshore marine ecosystems around the emergent islands of RN/SyG and Desventuradas are known to have some of the highest marine endemism anywhere on Earth [29, 54, 67]. Recent genetic studies have confirmed that Rapa Nui is an endemism hotspot: a location for the emergence of small-range endemic fishes (likely resulting from founder-event speciation), a route of dispersion for larger-range endemics, and a stepping stone for the diversification of some groups [90]. Fig 9. Distance-based redundancy analysis (dbRDA) ordination to investigate the relationship between the environmental variables and fish assemblages. Bray-Curtis similarity matrix based on 4th root-transformed MaxN higher level fish taxa. Symbol sizes are proportional to depth. https://doi.org/10.1371/journal.pone.0253213.g009 PLOS ONE Deep-sea biodiversity along the Salas y Go´ mez and Nazca ridges PLOS ONE | https://doi.org/10.1371/journal.pone.0253213 June 30, 2021 17 / 27