ABSTRACT
Deep-sea hydrothermal vent systems are under investigation for metal and rare earth element exploitations. The negative impacts on natural and endemic populations in these areas are still unclear. Larval dispersal is critical for colonization and settlements of populations in marine environments, and assessing connectivity is challenging, especially in deep-sea environments. Here, we investigate the potential of elemental fingerprinting of mollusc larval shells to discriminate larvae origins between multiple hydrothermal sites in the Southwest Pacific Ocean. We identified the gastropod Shinkailepas tollmanni as a suitable candidate as this species uses capsules to hold larvae before dispersal, which facilitates sampling. Cutting-edge femto-second laser ablation was performed to obtain individual measurements on 600 larval shells. We used classification methods to discriminate the origin of these individuals from 14 sampled hydrothermal sites across 3,500 km, with an overall success rate of 70%. When considering less sites within a more restricted area, reflecting dispersal distances inferred from genetic or modelling approaches, we increase the success rate up to 86%. We conclude that elemental fingerprinting is a suitable method to assess connectivity from hydrothermal vent populations, and that the measurements of preserved larval shells in juvenile individuals (i.e., those who completed dispersal) can give reliable information on their geographic origin.
Competing Interest Statement
The authors have declared no competing interest.
