Japan: Vents and Seeps in Close Proximity
59
Citation
58
Reference
10
Related Paper
Citation Trend
Keywords:
Chemosynthesis
Petroleum seep
Cold seep
Megafauna
Taphonomy
Petroleum seep
Chemosynthesis
Cold seep
Devonian
Taphonomy
Cite
Citations (531)
Exploration of the deep ocean (>200 m) is taking on added importance as human development encroaches. Despite increasing oil and natural gas exploration and exploitation, the deep ocean of Trinidad and Tobago is almost entirely unknown. The only scientific team to image the deep seafloor within the Trinidad and Tobago Exclusive Economic Zone was from IFREMER in the 1980s. That exploration led to the discovery of the El Pilar methane seeps and associated chemosynthetic communities on the accretionary prism to the east of Trinidad and Tobago. In 2014, the E/V Nautilus, in collaboration with local scientists, visited two previously sampled as well as two unexplored areas of the El Pilar site between 998 and 1629 m depth using remotely operated vehicles. Eighty-three megafaunal morphospecies from extensive chemosynthetic communities surrounding active methane seepage were observed at four sites. These communities were dominated by megafaunal invertebrates including mussels (Bathymodiolus childressi), shrimp (Alvinocaris cf. muricola), Lamellibrachia sp. 2 tubeworms, and Pachycara caribbaeum. Adjacent to areas of active seepage was an ecotone of suspension feeders including Haplosclerida sponges, stylasterids and Neovermilia serpulids on authigenic carbonates. Beyond this were large Bathymodiolus shell middens. Finally there was either a zone of sparse octocorals and other non-chemosynthetic species likely benefiting from the carbonate substratum and enriched production within the seep habitat, or sedimented inactive areas. This paper highlights these ecologically significant areas and increases the knowledge of the biodiversity of the Trinidad and Tobago deep ocean. Because methane seepage and chemosynthetic communities are related to the presence of extractable oil and gas resources, development of best practices for the conservation of biodiversity in Trinidad and Tobago waters within the context of energy extraction is critical. Potential impacts on benthic communities during oil and gas activities will likely be long lasting and include physical disturbance during drilling among others. Recommendations for the stewardship of these widespread habitats include: (1) seeking international cooperation; (2) holding wider stakeholder discussions; (3) adopting stringent environmental regulations; and (4) increasing deep-sea research to gather crucial baseline data in order to conduct appropriate marine spatial planning with the creation of marine protected areas.
Chemosynthesis
Petroleum seep
Megafauna
Cold seep
Remotely operated vehicle
Authigenic
Seafloor Spreading
Cite
Citations (38)
Cold seep
Chemosynthesis
Petroleum seep
Adductor muscles
Cite
Citations (11)
One of the main limitations to understanding the evolutionary history of hydrothermal vent and cold seep communities is the identification of tube fossils from ancient deposits. Tube-dwelling annelids are some of the most conspicuous inhabitants of modern vent and seep ecosystems, and ancient vent and seep tubular fossils are usually considered to have been made by annelids. However, the taxonomic affinities of many tube fossils from vents and seeps are contentious, or have remained largely undetermined due to difficulties in identification. In this study, we make a detailed chemical (Fourier-transform infrared spectroscopy and pyrolysis gas-chromatography mass-spectrometry) and morphological assessment of modern annelid tubes from six families, and fossil tubes (seven tube types from the Cenozoic, 12 Mesozoic and four Palaeozoic) from hydrothermal vent and cold seep environments. Characters identified from these investigations were used to explore for the first time the systematics of ancient vent and seep tubes within a cladistic framework. Results reveal details of the compositions and ultrastructures of modern tubes, and also suggest that two types of tubes from ancient vent localities were made by the annelid family Siboglinidae, which often dominates modern vents and seeps. Our results also highlight that several vent and seep tube fossils formerly thought to have been made by annelids cannot be assigned an annelid affiliation with any certainty. The findings overall improve the level of quality control with regard to interpretations of fossil tubes, and, most importantly, suggest that siboglinids likely occupied Mesozoic vents and seeps, greatly increasing the minimum age of the clade relative to earlier molecular estimates.
Annelid
Cold seep
Petroleum seep
Chemosynthesis
Taphonomy
Cite
Citations (37)
Chemosynthesis
Cold seep
Fossil Record
Petroleum seep
Hydrocarbon exploration
Taphonomy
Geologic record
Cite
Citations (39)
Problems with the identification of tubular fossils from ancient hydrothermal vent and cold seep deposits have hindered understanding of the evolutionary history of vent and seep communities. This thesis aims to (1) improve knowledge of lesser-studied tubicolous annelids occupying vents and seeps, (2) study the diversity of tubes at vents and seeps, (3) investigate the fossilisation of tubes within modern vents and seeps, (4) better interpret the fossil record, and (5) provide insights into the palaeoecology these environments. Results presented here on investigations of Sclerolinum contortum, a species belonging to a little- studied genus of the major vent/seep dwelling annelid family Siboglinidae, demonstrate that it exhibits tube morphological plasticity, wide habitat preferences and a global distribution spanning the Arctic to the Southern Ocean. These results also suggest that this species has dispersed throughout this range using chemosynthetic habitats as stepping stones. A detailed investigation of the full mineralisation process of Alvinella (Alvinellidae) tubes at modern hydrothermal vents shows that these tubes are fossilised by pyrite and silica that template organic tube layers, and that microorganisms living on tube surfaces are also exceptionally well-preserved alongside the tubes. No known ancient vent tube fossils resemble mineralised Alvinella tubes. A major morphological and compositional comparison of both modern and fossil tubes from vents and seeps revealed that two fossil tube types from the Mesozoic were likely made by vestimentiferans (Siboglinidae), suggesting that this major vent and seep annelid lineage has a longer history within vents and seeps than proposed by molecular clock age estimates. This analysis also demonstrates the need for greater caution in assigning affinities to fossil vent and seep tubes. Finally, this thesis reports the remarkable preservation of filamentous microorganisms on the walls of Silurian vent tube fossils, giving the first insights into ecological associations between microbes and metazoans within the oldest known hydrothermal vent community.
Chemosynthesis
Cold seep
Taphonomy
Petroleum seep
Paleoecology
Annelid
Tetrapod (structure)
Cite
Citations (1)
Chemosynthesis
Petroleum seep
Cold seep
Megafauna
Taphonomy
Cite
Citations (59)
Chemosynthesis
Petroleum seep
Cold seep
Taphonomy
Cite
Citations (41)
Symbiosis of chemoautrophic bacteria with the members of hydrothermal vent and cold seep communities in the deep-sea were examined by histology using transmission electron microscopy; Bathymodiolus spp. from Sagami Bay, the Iheya Ridge and the North Fiji Basin; and Ifremeria nautilei from the North Fiji Basin. Two species of Bathymodiolus, each from Sagami Bay and the Iheya Ridge harbored methane-oxidizing symbionts within their gill tissues. Vent gastropod Ifremeria nautilei from the hydrothermal vents of the North Fiji Basin housed two types of symbionts; one sulfur-oxidizing type and the other methane-oxidizing type. The occurrence of chemosynthetic symbionts in these organisms were expected before-hand based on the ecological observations of their habit. The other members of these groups from world oceans and the recent advances in the symbiosis of the vent and seep communities were reviewed.
Chemosynthesis
Petroleum seep
Cold seep
Seabed
Cite
Citations (0)