Abstract
Communities in spatially fragmented deep-sea hydrothermal vents rich in polymetallic sulfides could soon face major disturbance events due to deep-sea mineral mining, such that unraveling patterns of gene flow between hydrothermal vent populations will be an important step in the development of conservation policies. Indeed, the time required by deep-sea populations to recover following habitat perturbations depends both on the direction of gene flow and the number of migrants available for re-colonization after disturbance. In this study we compare nine dirivultid copepod species across various geological settings. We analyze partial nucleotide sequences of the mtCOI gene and use divergence estimates (FST) and haplotype networks to infer intraspecific population connectivity between vent sites. Furthermore, we evaluate contrasting scenarios of demographic population expansion/decline versus constant population size (using, for example, Tajima’s D). Our results indicate high diversity, population expansion and high connectivity of all copepod populations in all oceans. For example, haplotype diversity values range from 0.89 to 1 and FST values range from 0.001 to 0.11 for Stygiopontius species from the Central Indian Ridge, Mid Atlantic Ridge, East Pacific Rise, and Eastern Lau Spreading Center. We suggest that great abundance and high site occupancy by these species favor high genetic diversity. Two scenarios both showed similarly high connectivity: fast spreading centers with little distance between vent fields and slow spreading centers with greater distance between fields. This unexpected result may be due to some distinct frequency of natural disturbance events, or to aspects of individual life histories that affect realized rates of dispersal. However, our statistical performance analyses showed that at least 100 genomic regions should be sequenced to ensure accurate estimates of migration rate. Our demography parameters demonstrate that dirivultid populations are generally large and continuously undergoing population growth. Benthic and pelagic species abundance data support these findings.
Highlights
Deep-sea hydrothermal vents are island habitats that occur globally along mid-ocean ridges, back-arc basins and island arcs
Our analyses provide a basis for discussing whether the frequencies of vent fields and volcanic eruptions can shape the genetic composition of populations
Copepod specimens were collected by the submersible Alvin on the East Pacific Rise (EPR) and the Guaymas Basin (GB) in the East Pacific, by the submersible Nautile on the Mid-Atlantic Ridge (MAR) in the Atlantic, by the ROV Jason the Eastern Lau Spreading Center (ELSC) in the West Pacific, and by the ROV Kiel 6000 on the Central Indian Ridge (CIR) in the Indian Ocean (Fig 1)
Summary
Deep-sea hydrothermal vents are island habitats that occur globally along mid-ocean ridges, back-arc basins and island arcs. Most vent macrofauna and several meiofauna species are restricted to the vent environment, where the sulfide-rich fluids nourish chemolithoautotrophic bacteria [1,2,3]. The rich sulfide mineral deposits at deep-sea hydrothermal vents could make this unique ecosystem a target area for the mining industry in the near future [5]. Seabed crawlers utilized in this industry use cutters to shred mineral deposits, resulting in large scale disturbances on the faunal communities living at hydrothermal vents [6]. Conservation policies depend on predictions as to whether species have the potential to recolonize impacted areas and, contribute to the recovery of communities after such major disturbance events
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
