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1.
Spatial distribution, diversity, and composition of bacterial communities within the shallow sub-seafloor at the deep-sea hydrothermal field of the Suiyo Seamount, Izu-Bonin Arc, Western Pacific Ocean, were investigated. Fluids were sampled from four boreholes in this area. Each borehole was located near or away from active vents, the distance ranging 2–40 m from active vents. In addition, fluids discharging from a natural vent and ambient seawater were sampled in this area. We extracted DNA from each sample, amplified bacterial 16S rRNA genes by PCR, cloned the PCR products and sequenced. The total number of clones analyzed was 348. Most of the detected phylotypes were affiliated with the phylum Proteobacteria, of which the detection frequency in each clone library ranged from 84.6% to 100%. The bacterial community diversity and composition were different between hydrothermal fluids and seawater, between fluids from the boreholes and the vent, and even among fluids from each borehole. The relative abundances of the phylotypes related to Thiomicrospira, Methylobacterium and Sphingomonas were significantly different among fluids from each borehole. The phylotypes related to Thiomicrospira and Alcanivorax were detected in all of the boreholes and vent samples. Our findings provide insights into bacterial communities in the shallow sub-seafloor environments at active deep-sea hydrothermal vent fields.  相似文献   

2.
Western Pacific hydrothermal vents will soon be subjected to deep‐sea mining and peripheral sites are considered the most practical targets. The limited information on community dynamics and temporal change in these communities makes it difficult to anticipate the impact of mining activities and recovery trajectories. We studied community composition of peripheral communities along a cline in hydrothermal chemistry on the Eastern Lau Spreading Center and Valu Fa Ridge (ELSC‐VFR) and also studied patterns of temporal change. Peripheral communities located in the northern vent fields of the ELSC‐VFR are significantly different from those in the southern vent fields. Higher abundances of zoanthids and anemones were found in northern peripheral sites and the symbiont‐containing mussel Bathymodiolus brevior, brisingid seastars and polynoids were only present in the northern peripheral sites. By contrast, certain faunal groups were seen only in the southern peripheral sites, such as lollipop sponges, pycnogonids and ophiuroids. Taxonomic richness of the peripheral communities was similar to that of active vent communities, due to the presence of non‐vent endemic species that balanced the absence of species found in areas of active venting. The communities present at waning active sites resemble those of peripheral sites, indicating that peripheral species can colonize previously active vent sites in addition to settling in the periphery of areas of venting. Growth and mortality were observed in a number of the normally slow‐growing cladorhizid stick sponges, indicating that these animals may exhibit life history strategies in the vicinity of vents that differ from those previously recorded. A novel facultative association between polynoids and anemones is proposed based on their correlated distributions.  相似文献   

3.
Spatial patterns and morphology of hydrothermal vents and the occurrence of vent-associated megafauna were investigated in the back-arc basin system of the Okinawa Trough, western Pacific. Amongst hydrothermal vent fields located on the rising slopes to the NE and S of the basin, the Iheya North area has been subjected to a series of intensive diving surveys. Hydrothermal vents demonstrated concentrated patterns of distribution on different spatial scales. In Iheya North, the majority of vents occurred in lines parallel to the NE to W/SW alignment of the spreading axis, within a radius of ca. 200 m around the most active sulphide structure with the highest recorded fluid temperature of over 300°C. The morphology of hydrothermal vents varied greatly from an incipient flat rock with crevices to a 20- to 30-m-tall, multi-flanged structure with concomitant variation in the distribution and abundance of vent-associated megafauna, particularly a galatheid Shinkaia crosnieri and Bathymodiolus mussels. Comparison of active and inactive vents revealed that the spatial extent of Shinkaia ‘aggregation’ (a group of individuals with short nearest-neighbour distances) effectively defined a habitat unit of this species, and active hydrothermal chimneys contained more of these units, leading to greater spatial occupancy by Shinkaia. Given the temporally unstable nature of vent structures as recognised by repeated surveys, vent assemblages are thought to be closely dictated by the spatio-temporal dynamics of vents in the Okinawa Trough back-arc system.  相似文献   

4.
杨梅  李新正 《海洋科学》2017,41(6):126-133
深海热液口及其生物群落自1977年发现以来,受到海洋生物学界的广泛关注。近年来伴随深海调查技术的进步,大量热液生物群落相继被发现,并在生物地理学、生态学和生物多样性方面取得了显著的进展。目前,受采样不足及分类学研究的限制,针对深海热液口的遗传多样性研究多集中于大型底栖生物。本文拟对该领域的研究成果进行简要综述,以期加深对深海热液口大型底栖生物的物种分布模式、扩散途径及群体连通性的认识,为深海热液口生物多样性的研究提供新视角。  相似文献   

5.
Habitat created or modified by the physical architecture of large or spatially dominant species plays an important role in structuring communities in a variety of terrestrial, aquatic, and marine habitats. At hydrothermal vents, the giant tubeworm Riftia pachyptila forms large and dense aggregations in a spatially and temporally variable environment. The density and diversity of smaller invertebrates is higher in association with aggregations of R. pachyptila than on the surrounding basalt rock seafloor. Artificial substrata designed to mimic R. pachyptila aggregations were deployed along a gradient of productivity to test the hypothesis that high local species diversity is maintained by the provision of complex physical structure in areas of diffuse hydrothermal flow. After 1 year, species assemblages were compared among artificial aggregations in low‐, intermediate‐, and high‐productivity zones and compared to natural aggregations of R. pachyptila from the same site. Hydrothermal vent fauna colonized every artificial aggregation, and both epifaunal density and species richness were highest in areas of high chemosynthetic primary production. The species richness was also similar between natural aggregations of R. pachyptila and artificial aggregations in intermediate‐ and high‐productivity zones, suggesting that complex physical structure alone can support local species diversity in areas of chemosynthetic primary production. Differences in the community composition between natural and artificial aggregations reflect the variability in microhabitat conditions and biological interactions associated with hydrothermal fluid flux at low‐temperature hydrothermal vents. Moreover, these local ecological factors may further contribute to the maintenance of regional species diversity in hydrothermal vent communities on the East Pacific Rise.  相似文献   

6.
Investigations of the diffusion activities both within and outside the seafloor hydrothermal vents, as well as related mineral genesis, have been one of the key focuses of ocean biogeochemistry studies. Many hydrothermal vents are distributed close to the southern Okinawa Trough on the less-than-30-m deep shallow seafloor off Kueishan Tao, northeast of Taiwan Island. Investigations of temperature, pH and Eh at four depths of hydrothermal plume were carried out near Kueishan Tao at the white(24.83°N, 121.96°E) and yellow(24.83°N, 121.96°E) vents. An 87 h of temperature time series observation-undertaken near the white vent showed that tide is the main factor affecting the background environment. Based on the observed data, 3-dimensional sliced diffusion fields were obtained and analyzed. It was concluded that the plume diffused mainly from north to south due to ebb tide. The yellow vent's plume could effect as far as the white vent surface. From the temperature diffusion field, the vortices of the plume were observed. The Eh negative abnormality was a better indicator to search for hydrothermal plumes and locate hydrothermal vents than high temperature and low pH abnormalities.  相似文献   

7.
曾志刚 《海洋与湖沼》2021,52(6):1333-1349
海底热液活动调查研究是深海进入、深海探测和深海开发的切入点之一。近十年来,中国在西太平洋弧后盆地、东太平洋海隆、大西洋洋中脊和印度洋脊,发现了一批新的海底热液活动区,围绕着热液活动区的硫化物、流体、热液柱、生物等热液产物开展了调查研究,构建了海底热液地质学,提出了热液活动、冷泉及天然气水合物的同源异汇假说,出版了《海底热液地质学》、《现代海底热液硫化物成矿地质学》、《现代海底热液活动》、《东太平洋海隆热液地质》专著,获得了一批调查研究成果。未来,聚焦海底热液活动的深部过程及其资源环境效应关键问题,发展海底热液活动探测技术,拓展极地海底热液活动调查研究新领域,围绕烟囱体、热液柱、含金属沉积物、流体以及热液区生物等热液产物,开展深入、系统的调查研究工作,无疑将推动海底热液地质学取得新的进展。  相似文献   

8.
The structure of the assemblages associated with the mussel aggregations of Bathymodiolus azoricus was investigated. The mussel beds were found on the hydrothermal vent fields on the Mid-Atlantic Ridge (the Menez Gwen, Lucky Strike, and Rainbow areas) at the depths of 850–2400 m. The community structure of the mussel bed assemblages varied between the studied areas. Large number of species was unique to Menez Gwen mussel beds; the most observed taxa were not specialized hydrothermal species. All the other, nonunique species were found for the Lucky Strike region. The lowest mussel assemblage structure evenness was observed in the shallowest area, the Menez Gwen area (850 m depth). We assume that two types of mussel assemblages—nematode-dominated and copepod-dominated ones—exist in the Lucky Strike field. The assemblages of B. azoricus differ significantly from the assemblages of B. thermophilus inhabiting the Pacific hydrothermal vents.  相似文献   

9.
Near the Azores Triple Junction as the Azores Plateau is approached, the ridge axis becomes shallower; its depth decreases from ca. 2400 m in the Rainbow vent field (36°13′N) to ca. 850 m in the Menez Gwen vent field (37°35′N). In this area, extensive mussel beds of the mytilid Bathymodiolus azoricus dominate the hydrothermal vent fauna, along with populations of three shrimps (Rimicaris exoculata, Mirocaris fortunata and Chorocaris chacei). The main physical and chemical characteristics of the vent habitat were studied by discrete sampling, in situ analysis and sediment trap moorings. The vent fauna is distributed along a variable band where the vent fluids and seawater mix, with R. exoculata living in the most concentrated areas and Bathymodiolus azoricus in the most diluted zones. Various non-endemic species live at the border of the vent field. The variations observed in structure and composition of the communities along the depth gradient are most likely due to changes in vent fluid toxicity (metallic and sulphide content) and suspended mineral particles, which render the fluids harsher for species living there. The main faunal differences observed between Lucky Strike and Menez Gwen hydrothermal fields are due to an impoverishment in the hydrothermal endemic species and to the penetration of bathyal species. The comparison of the three studied vent fields suggests the existence of a succession of several biogeographic islands rather than a single province.  相似文献   

10.
TheSnake Pit Hydrothermal Site lies on the axis of the Mid-Atlantic Ridge at 23°22′ N latitude, about 30 km south of the Kane Transform Intersection. Active ‘black smoker’ vents and a surrounding field of hydrothermal sediment occur at the crest of a laterally extensive neovolcanic ridge. It is one of the first active hydrothermal vent fields to be found on a slow-spreading ridge axis and despite significant differences in its geologic setting from those of the East Pacific Rise, has many similarities to its fast-spreading counterparts. Although preliminary reports have documented many interesting aspects of these vents and their surroundings, new data collected from the manned submersible ALVIN and the deep-towed ANGUS camera system define the regional tectonic setting as well as the local geologic environment of this fascinating area. The Snake Pit vents are located on a local peak of a volcanic constructional ridge at a depth of 3450 m, 700–800 m deeper than vents known from the East Pacific Rise, Galapagos, or Juan de Fuca spreading centers. The vent field is at least 600 m long and up to 200 m wide and is covered by a thick blanket of greenish to yellow-orange hydrothermal sediment. Both active and extinct vents are perched along the crests of steep-sided sulfide mounds that reach heights of over 40 m. High-temperature (350° C) fluids are vented from black smoker chimneys and low-temperature (226° C) fluids seep from sulphide domes and subordinate anhydrite constructions. Water temperatures, flow rates, fluid chemistries, and mineralization are strikingly similar to vents of faster spreading ridge crests; however, a somewhat distinct fauna inhabit the area.  相似文献   

11.
A sediment sample was collected from a deep-sea hydrothermal vent field located at a depth of 2 951 m on the Southwest Indian Ridge. Phylogenetic analyses were performed on the prokaryotic community using polymerase chain reaction（PCR） amplification of the 16 S rRNA and nifH genes. Within the Archaea, the dominant clones were from marine benthic group E（MBGE） and marine group I（MGI） belonging to the phyla Euryarchaeota and Thaumarchaeota, respectively. More than half of the bacterial clones belonged to the Proteobacteria, and most fell within the Gammaproteobacteria. No epsilonproteobacterial sequence was observed. Additional phyla were detected including the Actinobacteria, Bacteroidetes, Planctomycetes, Acidobacteria, Nitrospirae, Chloroflexi, Chlorobi, Chlamydiae, Verrucomicrobia, and candidate divisions OD1, OP11, WS3 and TM6, confirming their existence in hydrothermal vent environments. The detection of nifH gene suggests that biological nitrogen fixation may occur in the hydrothermal vent field of the Southwest Indian Ridge. Phylogenetic analysis indicated that only Clusters I and III NifH were present. This is consistent with the phylogenetic analysis of the microbial 16 S rRNA genes, indicating that Bacteria play the main role in nitrogen fixation in this hydrothermal vent environment.  相似文献   

12.
Mesoscale distribution of the density and productivity of bacterioplankton at representative geological locations in the rift ecosystem of the North Fiji Basin were clarified by sampling using a mannedShinkai 6500 submersible. The bacterioplankton density inside the hot and warm fluids of hydrothermal vents was one order magnitude greater than that in the deep water outside the vent plume. The bacterial production was highest inside the hot and warm vent fluids, and was higher just outside the hot and warm vent fluids than further outside in the deep water surrounding the vent plume, respectively. Productivity from outside to inside the vent fluid varied from 0.01 to 0.71 gC m–3 day–1.  相似文献   

13.
Macrofaunal assemblages with the prevalence of Bresiliidae shrimp and Mytilidae mussels are abundant in the hydrothermal vents along the Mid-Atlantic Ridge. The mussels inhabit the zone of diffuse seeps of hydrothermal fluids with temperature abnormalities up to several degrees. Shrimps inhabit an extreme biotope in the mixed interface between the seawater and the hydrothermal fluid at a temperature up to 20–30°C. We studied the mussel and shrimp assemblages in three hydrothermal vent fields: the Rainbow, Broken Spur, and Snake Pit. The species richness of the mussel assemblages in at least two regions (Broken Spur and Snake Pit) is higher as compared with the shrimps of the same hydrothermal vent fields. The fauna inhibiting the shrimp swarms lack almost any taxa specific for particular assemblages: almost all the taxa are also present in the mussel beds. The structure of the shrimp assemblage is less homogeneous as compared with that of the mussel assemblage. The population prevalence of one taxon (Copepoda) in the shrimp assemblage is most likely connected with the extreme and unstable conditions of the biotope occupied by the shrimps in the hydrothermal field. The taxonomic similarity between the mussel and shrimp assemblages within one hydrothermal vent field is higher as compared with the similarity between the mussel (or shrimp) assemblages from different fields.  相似文献   

14.
Larval transport from distant populations is essential for maintenance and renewal of populations in patchy and disturbed ecosystems such as deep-sea hydrothermal vents. We use quasi-geostrophic modeling to consider the potential for long-distance dispersal of hydrothermal vent larvae in mesoscale eddies interacting with the northern East Pacific Rise. Modeled eddy dynamics were similar to the observed propagation dynamics of Tehuantepec eddies, including their ability to cross the ridge. Simulated surface anticyclones were associated with coherent cyclones in the deep layer with relatively strong current velocities that could significantly increase the dispersal potential of passive particles. Eddy interactions with ridge topography further enhanced tracer dispersal along the ridge axis through shearing and elongation of the eddy core. Simulations suggest that the passage of an eddy would result in local loss from the vent field and aggregate transport with potential enhancement of dispersal between vent fields separated by up to 270 km. Based on the latitude at which most Tehuantepec eddies cross the ridge, eddy-induced flows would enhance connectivity between the 13°N, 11°N, and 9°N vent fields along the East Pacific Rise asymmetrically with higher transport from northern vent fields to southern vent fields.  相似文献   

15.
台湾近海热液体系独特的生物及地球化学特征   总被引：1，自引：1，他引：0  
陈雪刚  吴斌  郑豪  樊炜  叶瑛  陈镇东 《海洋学报》2019,41(10):161-168
台湾地处西太平洋构造活动带，近海发育了多处热液活动，其中最典型的为龟山岛和绿岛热液体系。本文对海峡两岸在龟山岛和绿岛热液的地球化学特征以及周边生物体的响应的研究进展进行了综述。龟山岛热液喷出流体具有全球最低的pH(1.52)，富含重金属元素和CO2等酸性气体，是周围海水中有色溶解有机质的来源；绿岛具有全球热液中最低的溶解有机碳浓度(14 μmol /L)，且具有特殊的动力学特性。喷口周边分布了较为罕见的自然硫烟囱体和硫磺球。喷口的高毒性、高酸性热液改变了热液区生物体如螃蟹的生活习性和解毒机制。热液区的主要活跃菌群为参与碳、硫和氮代谢途径的γ-和ε-变形菌。主要生物质合成以硫还原和硫氧化的化能无机自养型生物为主，微生物硫代谢促进了热液系统中的微生物能量流动和元素循环作用。某些热液生物采用繁殖期迁徙的机制应对高毒性、高酸性热液环境。在热液活动的胁迫下，这些微生物产生了新颖独特的代谢产物。此外，龟山岛和绿岛热液体系还受到了潮汐、台风和地震等灾害性事件的影响。台湾近海热液体系的研究对认识热液地球化学循环、探讨热液的生态环境效应等具有重要的意义。  相似文献   

16.
Hydrothermal plume is an important constituent of seabed hydrothermal circulation and is also one of the characteristics of active hydrothermal vents. Portable Miniature Autonomous Plume Recorders （MAPR） attached to a towed deep-sea instrument was used to search for hydrothermal plumes and hydrothermal vents. We introduced the basic principle of MAPR based on deep towing technology to detect plumes, then analyzed the factors affecting the quality of the MAPR data and presented a data correction method for MAPR, including instrument location correction, noise reduction processing, system error elimination and seawater background reduction. Finally we applied the method to analyze MAPR data obtained during the Chinese DY115-21 cruise on R/VDayang Iin the “Precious Stone Mountain” hydrothermal field on the Gala-pagos Microplate. The results provided a better understanding of the distribution of the hydrothermal activ-ity in this field, indicating the presence of a new hydrothermal vent.  相似文献   

17.
During the Dives Nos. 409, 410, 480 and 481 of the Japanese submersible Shinkai 2000, conducted on June 10 and 11, 1989 and on May 16 and 17, 1990, several hydrothermal vents and prosperous vent associated biological communities were found on the northern slope of the Iheya Ridge in the Mid-Okinawa Trough (27°32.5′ N, 126°58.5′ E: depth 1,400 m). The first site we found, the “Calyptogena Site”, was characterized by a relatively thick blanket of sediments, pleated and/or laminated lava flows, with occasional lobate pillows and white and yellow stains. Although no remarkable shimmering water and thermal anomalies were detected during the observations, the extraordinarily dense community must be related to hydrothermal activities. The community was dominated by the giant white clam, Calyptogena okutanii, in biomass, and by Neolepas-type primitive scalpellids and slender vestimentiferan tube-worms in number. The second site, the “Pyramid Site”, situated only 200 m northward from the Calyptogena Site has typical clear smokers emitting hot water over 200°C, and is characterized by a hard substratum of volcanic rocks and hydrothermal slabs. No noteworthy succession was perceived at the Calyptogena Site over a year. Many of the vent members occurred at both sites. However, Calyptogena okutanii, which were confined to the sediment bottom, Neolepas spp. and larger vestimentiferan tube-worms were found to thrive only at the Calyptogena Site, being only minor elements in the Pyramid Site. The global distribution of several groups of organisms is discussed preliminarily in zoogeographical terms based on comparison with other submersible missions and surveys done by surface vessels. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

18.
Hydrothermal vent fields on the Mid-Atlantic Ridge (MAR) are small (no more than 0.1-1.0 km2) and widely spaced (a reported average of one field per 175 km between 11°N and 40°N). Their faunas are similar and usually dominated by shrimp of the family Bresiliidae. Little is known about the way these animals (and other members of the vent fauna) disperse and colonize new vents. Vent shrimp juveniles have been taken close to certain vent sites, and in midwater, but their larvae and postlarvae have not been captured. We report here that bresiliid shrimp postlarvae are very widely dispersed around the Broken Spur vent field and extend into the next MAR segment and the Atlantis Fracture Zone beyond. The populations show density gradients declining both vertically and horizontally from the vent site, in contrast to the overall pelagic biomass. This is the furthest recorded dispersal (> 100 km) of identified larvae from a hydrothermal vent and is sufficient to give them access to adjacent vent fields and thus the scope for colonising new sites.  相似文献   

19.
Abstract

Considerable effort has been expended in studying the Izu–Bonin Arc over the past 15 years. In particular, 43 dives of the Shinkai 2000 have been undertaken there to discover and evaluate the extent of submarine hydrothermal activity and mineralization. Most effort has been focused on Myojin Knoll (23 dives), Suiyo Seamount (6 dives), and Kaikata Caldera (10 dives).

The Izu–Bonin Arc is divided in two by the Sofugan Tectonic Line. Eight submarine caldera are located north of this line but only one is south of it. The physiography of the northern sector of the arc is quite different from that of the southern sector. Volcanic rocks from the northern sector are more acidic than those from the southern sector.

Evidence for submarine hydrothermal mineralization has been observed at four seamounts along the Izu–Bonin Arc (Myojin Knoll, Myojinsho, Suiyo Seamount, and Kaikata Caldera), and submarine hydrothermal activity is evident at another three seamounts along the arc (Kurose Hole, Mokuyo Seamount, and Doyo Seamount).

The most extensive submarine hydrothermal mineral deposit so far located on the Izu–Bonin Arc is the Sunrise deposit at Myojin Knoll. This deposit, at least 400 m in diameter and 30 m high, is associated with black smoker venting, inactive sulfide chimneys, massive sulfides, hydrothermal Mn crusts, and a hydrothermal vent fauna. The maximum recorded temperature of the hydrothermal vents there was 278°C. Some of the sulfide chimneys contained as much as 49 μg/g Au and 3,400 μg/g Ag. The sunrise deposit is one of the largest submarine volcanic massive sulfide deposits so far discovered in midocean ridge, backarc, or arc settings and has an estimated mass of 9 × 106 t. This deposit may be of the Kuroko-type. The discovery of the Sunrise deposit in 1997 gives hope that other, similarly large, sulfide deposits may be found in other caldera along the Izu–Bonin Arc.

The geological variability along the arc, the high seismicity, the occurrence of active volcanism and submarine hydrothermal venting, and a proven submarine hydrothermal mineral potential coupled with the proximity of the region to Japan suggest that the Izu–Bonin Arc could profitably serve as a natural laboratory for the long-term monitoring of the seafloor.  相似文献   

20.
This study provides an analysis of vesicomyid bivalve–symbiont community distribution across cold seep and hydrothermal vent areas in the Guaymas Basin (Gulf of California, Mexico). Using a combination of morphological and molecular approaches including fluorescent in situ hybridization (FISH), and electronic microscopy observations, vesicomyid clam species and their associated symbionts were characterized and results were analyzed in light of geochemical conditions and other on‐site observations. A greater diversity of vesicomyids was found at cold seep areas, where three different species were present (Phreagena soyoae [syn. kilmeri], Archivesica gigas, and Calyptogena pacifica). In contrast, A. gigas was the only species sampled across the hydrothermal vent area. The same haplotype of A. gigas was found in both hydrothermal vent and cold seep areas, highlighting possible contemporary exchanges among neighboring vents and seeps. In either ecosystem, molecular characterization of the symbionts confirmed the specificity between symbionts and hosts and supported the hypothesis of a predominantly vertical transmission. In addition, patterns of clams could reflect potential niche preferences for each species. The occurrence of numerous traces of vesicomyid movements on sediments in the sites colonized by A. gigas seemed to indicate that this species might have a better ability to move. Furthermore, variation in gill sulfur content could reveal a higher plasticity and sulfur storage capacity in A. gigas. Thus, the distribution of vesicomyid species across the chemosynthetic areas of the Guaymas Basin could be explained by differences in biological traits of the vesicomyid species that would allow A. gigas to more easily exploit transient and punctual sources of available sulfide than P. soyoae.  相似文献   

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