Population structure ofBathymodiolus manusensis, a deep-sea hydrothermal vent-dependent mussel from Manus Basin, Papua New Guinea

Abstract

Deep-sea hydrothermal vents in the western Pacific are increasingly being assessed for their potential mineral wealth. To anticipate the potential impacts on biodiversity and connectivity among populations at these vents, environmental baselines need to be established. Bathymodiolus manusensis is a deep-sea mussel found in close association with hydrothermal vents in Manus Basin, Papua New Guinea. Using multiple genetic markers (cytochrome C-oxidase subunit-1 sequencing and eight microsatellite markers), we examined population structure at two sites in Manus Basin separated by 40 km and near a potential mining prospect, where the species has not been observed. No population structure was detected in mussels sampled from these two sites. We also compared a subset of samples with B. manusensis from previous studies to infer broader population trends. The genetic diversity observed can be used as a baseline against which changes in genetic diversity within the population may be assessed following the proposed mining event.

Population connectivity of the hydrothermal-vent limpet Shinkailepas tollmanni in the Southwest Pacific (Gastropoda: Neritimorpha: Phenacolepadidae)

“…Shinkailepas tollmanni seems to have experienced a bottleneck event followed by a sudden expansion (Fig 3 and S1 Fig), despite its supposedly very large population size and distribution over an extensive (4,000-km) geographic range. Population expansion after a bottleneck has also been proposed for several other vent-endemic taxa in the Southwest Pacific, including I. nautilei, R. variabilis, the mytilid mussel Bathymodiolus manusensis, and chionelasmatid barnacle Eochionelasmus ohtai manusensis [14,15,71,72]. Of these, I. nautilei, B. manusensis and E. ohtai show "star-like" networks of COI haplotypes and negative values of Tajima's D or Fu's Fs, which collectively suggest recent expansion of their populations [14,71,72].…”

“…Population expansion after a bottleneck has also been proposed for several other vent-endemic taxa in the Southwest Pacific, including I. nautilei, R. variabilis, the mytilid mussel Bathymodiolus manusensis, and chionelasmatid barnacle Eochionelasmus ohtai manusensis [14,15,71,72]. Of these, I. nautilei, B. manusensis and E. ohtai show "star-like" networks of COI haplotypes and negative values of Tajima's D or Fu's Fs, which collectively suggest recent expansion of their populations [14,71,72]. Shinkailepas tollmanni and R. variabilis, in contrast, display more complex networks and extremely high levels of genetic diversity in each panmictic population (Table 2) [15].…”

“…nautilei , R . variabilis , the mytilid mussel Bathymodiolus manusensis , and chionelasmatid barnacle Eochionelasmus ohtai manusensis [ 14 , 15 , 71 , 72 ]. Of these, I .…”

“…manusensis and E . ohtai show “star-like” networks of COI haplotypes and negative values of Tajima’s D or Fu's Fs , which collectively suggest recent expansion of their populations [ 14 , 71 , 72 ]. Shinkailepas tollmanni and R .…”

260 Voyages Beneath the Sea: A global assessment of biodiversity and research effort at deep-sea hydrothermal vents

“…Managers, regulators, and mining companies 124 are working from incomplete data, with inferences about the consequences, as well as mitigation 125 and remediation practices, often drawn from studies of few vent ecosystems that are often 126 different from those in which the impacts are expected to occur. This is especially challenging as 127 biodiversity is frequently used as a proxy for resilience and as a metric for assessing biological 128 baselines (Sonter et al, 2018;Van Dover, 2010;Van Dover et al, 2017). 129 In order to better assess our current understanding of deep-sea hydrothermal vent 130 biodiversity, we undertook a survey of the last 40 years of vent research via cruise reports (post-131 research cruise summary documents that provide a day-to-day narrative of work at sea, as well as 132 momentary sample logs and observations) from research expeditions that made biological 133 observations at hydrothermal vents.…”