Active hydrothermal vents in the Woodlark Basin may act as dispersing centres for hydrothermal fauna

Abstract

Here we report the discovery of a high-temperature hydrothermal vent field on the Woodlark Ridge, using ship-borne multibeam echosounding and Remotely Operated Vehicle (ROV) exploration. La Scala Vent Field comprises two main active areas and several inactive zones dominated by variably altered basaltic rocks, indicating that an active and stable hydrothermal circulation has been maintained over a long period of time. The Pandora Site, at a depth of 3380 m, is mainly composed of diffuse vents. The Corto site, at a depth of 3360 m, is characterized by vigorous black smokers (temperature above 360 °C). The striking features of this new vent field are the profusion of stalked barnacles Vulcanolepas sp. nov., the absence of mussels and the scarcity of the gastropod symbiotic fauna. We suggest that La Scala Vent Field may act as a dispersing centre for hydrothermal fauna towards the nearby North Fiji, Lau and Manus basins.

Subtle limits to connectivity revealed by outlier loci within two divergent metapopulations of the deep‐sea hydrothermal gastropod Ifremeria nautilei

“…nautilei is genetically structured into two distinct populations from Manus and North‐Fh‐Fiji/Lau BABs. Our study extends these previous results to a finer scale, owing to our larger, nested sampling design that includes the newly discovered La Scala vent field in the Woodlark basin (Boulart et al, in press), the Futuna volcanic arc (Konn et al, 2016) and the newly discovered northernmost Mangatolo site at the entrance of the Lau basin. Using a 10,570 SNP genome‐wide data set—unprecedented for a hydrothermal species—, we confirm that I .…”

“…In addition to these divergence time estimates, the models allowed us to quantify the existence of an ongoing bidirectional and asymmetrical gene flow, with migration from North‐Fiji/Futuna/Lau to Manus/Woodlark being higher than in the opposite direction. Despite this slight asymmetry, a genetic influence of the Manus/Woodlark metapopulation was detected in North‐Fiji, which shows foreign alleles coming from the former rather than from the Lau/Futuna populations (also observed at mtDNA cox1 gene in Boulart et al, in press; Thaler et al, 2011), but not the other way around (i.e., influence of North‐Fiji/Futuna/Lau on Woodlark, but see below). This result is consistent with the geography of the region, because North‐Fiji and Woodlark are the closest BABs between the two metapopulations.…”

“…nautilei (Figure 1, Table ). This sampling includes samples from the newly discovered active site La Scala in the Woodlark basin (Boulart et al, 2022).…”

Contrasted phylogeographic patterns of hydrothermal vent gastropods along South West Pacific: Woodlark Basin, a possible contact zone and/or stepping-stone

“…the Manus, Lau and North Fiji Basins while some other active areas are insufficiently known, in particular the Woodlark Basin, or the Solomon and Vanuatu (ex New Hebrides) Trench [ 28 ]. Very recently, hydrothermal vent communities have been discovered and described for the first time in the Woodlark Basin [ 35 ]. These communities are not profoundly different from communities reported in other western Pacific back-arc basins.…”

Inter-Specific Genetic Exchange Despite Strong Divergence in Deep-Sea Hydrothermal Vent Gastropods of the Genus Alviniconcha

“…For instance, we found two samples with the two species in the Lau Basin, one in the Manus Basin (Susu) and one at a Futuna site. Both species were also found in syntopy at the base of hydrothermal vent chimneys at 3388 m depth at the newly discovered site “La Scala” in the Woodlark Basin (Boulart et al [ 71 ]). On the basis of these observations, these two species seem to follow a longitudinal gradient where A. boucheti is currently expanding from the west to the east, while A. kojimai is expanding in the opposite direction.…”