Meiofaunal nematode abundance, composition, and diversity at bathyal to hadal depths in the Southeast Pacific Ocean

Abstract

Seamounts have long been hypothesized to be biodiversity hotspots for benthic organisms, but there is limited empirical evidence to support that notion. The present study sampled meiofauna from different deep-sea sites in the Southeast Pacific Ocean (seamounts, abyssal plain, trench, island) to assess causative factors that influence meiofauna and nematode diversity and community composition. Evidence found in this study suggests that composition of meiofauna is influenced by biogeographic region and biogeochemical factors, and the high diversity that was observed at the majority of seamount sites may be related to intermediate levels of disturbance and/or variability in deposition of organic material. More studies are needed to understand the causes for why biodiversity of meiofauna is often high at seamounts, but it is plausible that seamounts are important biodiversity hotspots for nematodes and other meiofauna owing to the interaction between physical currents and erosion and variability in depositional regimes. This suggests that seamounts could be important sites for the conservation of benthic communities in the deep sea, and this should be considered in the development of marine management strategies.