The Inner Ear and its Coupling to the Swim Bladder in the Deep-Sea Fish Antimora rostrata (Teleostei: Moridae)

The inner ear structure of Antimora rostrata and its coupling to the swim bladder were analyzed and compared with the inner ears of several shallow-water species that also have similar coupling. The inner ear of Antimora has a long saccular otolith and sensory epithelium as compared to many other fishes. Some parts of the membranous labyrinth are thick and rigid, while other parts are thinner but attached tightly to the bony capsule. The partially rigid membranous labyrinth, along with its intimate connection to the swim bladder, may help the inner ear follow the sound oscillations from the swim bladder with better precision than would occur in a less rigid inner ear. In addition, the saccular sensory epithelium has an elaborate structure and an anterior enlargement that may be correlated with increased hearing sensitivity. Some of the features in the inner ear of Antimora may reflect the functional specialization of deep-water living and support the hypothesis that there is enhanced inner ear sensitivity in some deep-sea fishes.     

VentBase: Developing a consensus among stakeholders in the deep-sea regarding environmental impact assessment for deep-sea mining–A workshop report

Mining seafloor massive sulfides for metals is an emergent industry faced with environmental management challenges. These revolve largely around limits to our current understanding of biological variability in marine systems, a challenge common to all marine environmental management. VentBase was established as a forum where academic, commercial, governmental, and non-governmental stakeholders can develop a consensus regarding the management of exploitative activities in the deep-sea. Participants advocate a precautionary approach with the incorporation of lessons learned from coastal studies. This workshop report from VentBase encourages the standardization of sampling methodologies for deep-sea environmental impact assessment. VentBase stresses the need for the collation of spatial data and importance of datasets amenable to robust statistical analyses. VentBase supports the identification of set-asides to prevent the local extirpation of vent-endemic communities and for the post-extraction recolonization of mine sites.     

A large volume particulate and water multi-sampler with in situ preservation for microbial and biogeochemical studies

A new tool was developed for large volume sampling to facilitate marine microbiology and biogeochemical studies. It was developed for remotely operated vehicle and hydrocast deployments, and allows for rapid collection of multiple sample types from the water column and dynamic, variable environments such as rising hydrothermal plumes. It was used successfully during a cruise to the hydrothermal vent systems of the Mid-Cayman Rise. The Suspended Particulate Rosette V2 large volume multi-sampling system allows for the collection of 14 sample sets per deployment. Each sample set can include filtered material, whole (unfiltered) water, and filtrate. Suspended particulate can be collected on filters up to 142 mm in diameter and pore sizes down to 0.2 μm. Filtration is typically at flowrates of 2 L min⁻¹. For particulate material, filtered volume is constrained only by sampling time and filter capacity, with all sample volumes recorded by digital flowmeter. The suspended particulate filter holders can be filled with preservative and sealed immediately after sample collection. Up to 2 L of whole water, filtrate, or a combination of the two, can be collected as part of each sample set. The system is constructed of plastics with titanium fasteners and nickel alloy spring loaded seals. There are no ferrous alloys in the sampling system. Individual sample lines are prefilled with filtered, deionized water prior to deployment and remain sealed unless a sample is actively being collected. This system is intended to facilitate studies concerning the relationship between marine microbiology and ocean biogeochemistry.     

深海研究中的底栖有孔虫：回顾与展望

底栖有孔虫在古环境研究中的应用先是用作古水深或水团的标志物。随着新技术的应用,识别出了2种不同的底栖有孔虫微生境：外生种和内生种;认识到甚至深海底栖有孔虫,也能对表层浮游生物勃发的季节性短暂事件作出响应,因为沉降到海底的有机物质供养着底栖有孔虫。目前,底栖有孔虫被广泛应用于估算海洋表层生产力和底层水团的含氧量。回顾了深海底栖有孔虫生态研究的历史和其在古海洋学中的应用,并强调研究、应用中的新方法、新技术。中国已经加入了诸如IODP等深海研究计划,有必要向我国学术界提供底栖有孔虫研究的新方向,以资参考。     

Apparent Microfloral Response to Organic Degradation on Bathyal ­Seafloor: An Analysis Based on Sediment Fatty Acids

Abstract. Abyssal microfloral succession induced by experimental organic degradation was investigated. Notable changes in amounts and compositions of short-chain (C9-20) sediment fatty acids were observed, which indicated the shift of sediment microflora. Biomarker fatty acids for methanotrophs and sulfate-reducing bacteria dominated. Resultant fatty acid compositions were most closely related to those from a nearby methane seep harboring a dense Calyptogena colony; the clams were also seen in close vicinity of the deployed organic mass. These observations suggest that the organic degradation on the bathyal seafloor stimulates the formation of methanotrophic and thio­trophic microflora, resulting in the formation of a methane-seep-type benthic community.     

Influence of Velocity and Types of Beam Trawl Towing on Deep-Sea Demersal Fish and Decapod Crustacean Samples

The sampling efficiency of two types of beam trawl towed at different velocities was compared when sampling deep-sea demersal fish and decapod crustaceans. The trawls were a Sigsbee-Agassiz type of 2 m span, and an Oregon type of 3 m span. The different hauls caught by the Oregon type beam trawl of 3 m span towed at 1.5 knot (3m 1.5 kt), the Oregon type towed at 0.8 knot (3m 0.8 kt) and the Sigsbee-Agassiz type towed at 1.5 knot (2m 1.5 kt) were compared by analysis of variance (ANOVA), the Tukey test, cluster analysis based on Morisita-Horn index, and correspondence analysis. The minimum viable sample size was determined by a randomization test. For demersal fish, the type of gear used had more influenced on the samples obtained than the towing velocity. For decapod crustaceans, no significant difference was detected between different trawls towed at different velocities. The common idea that if these types of trawl are towed at 1 knot or more, they cannot efficiently sample epifauna, but demersal fish can be well sampled, should be abandoned. The samples of demersal fish caught by 3m 1.5 kt revealed the greatest consistency and lowest variation than the others. We recommend using an Oregon type beam trawl of 3 m span towed at 1.5 knot as an ordinary deep-sea sampling device. Only a single successful haul or a sample size of 52 individuals was sufficient for estimating demersal fish diversity, but at least two successful hauls or a sample size of 54 individuals were needed for decapod crustaceans. If possible, seven successful hauls or a sample size of 189 individuals of decapod crustaceans are recommended for community study. This revised version was published online in July 2006 with corrections to the Cover Date.     

深海富REY泥中稀土元素赋存载体及其富集机制研究进展

综合前人发表的关于太平洋、大西洋以及印度洋等深海沉积物中稀土元素含量的数据,本文较为系统地阐述了全球深海富REY泥(REY-rich mud)的分布,分析了不同沉积环境下富REY泥中稀土元素的赋存载体及其控制因素,并进一步探讨了赋存载体中稀土元素的富集机制。研究发现深海富REY泥主要分布在太平洋和印度洋的深海盆地中,其中西北太平洋南鸟岛附近海域沉积物中稀土元素最为富集,是较为有利的稀土资源勘探潜力区。邻近热液区,深海沉积物中稀土元素含量受热液活动影响较大,稀土元素的主要赋存相是Fe-Mn水合(氢)氧化物,可能是热液流体扩散过程中,颗粒物中的Fe-Mn水合(氢)氧化物等吸附(scavenge)海水中的稀土元素所致。而在远离热液区的正常深海富REY泥中,高磷含量以及低沉积速率是导致其稀土含量相对较高的主要因素,赋存载体主要是生物成因磷灰石(鱼牙骨碎屑)。在磷灰石早期成岩阶段,海水和孔隙水中的REY进入磷灰石,在羟基磷灰石晶格中REE~(3+)与磷灰石中的Ca~(2+)发生类质同象替代:REE~(3+)+Na~+?2Ca~(2+)和REE~(3+)+Si~(4+)?Ca~(2+)+P~(5+),使其不断地富集稀土元素,但这还需要进一步研究。     

Spatial distribution, diversity and composition of bacterial communities in sub-seafloor fluids at a deep-sea hydrothermal field of the Suiyo Seamount

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.     

挪威深海矿产资源开采战略路径分析及启示

挪威近年来大力推动深海采矿,在地质科研勘探、技术装备研制、环保政策制定等领域已经走在世界前列,率先为深海采矿商业化提供了实现可能。挪威政府凭借其过硬的工程装备基础与深厚的法律政策积淀,因时制宜积极转变深海采矿路径,目前已在商业化开发与环境保护中找到平衡点,形成了完备的深海开发战略路径。文章通过中国和挪威两国深海资源开展战略对比分析,提出4点建议：加快深海产学研深度合作,带动新兴产业发展;以《深海法》为基石,构建深海采矿产业政策;加强深海环境保护研究,打造环境友好的深海开发路线;把握深海国际机制,争取深海国际规则主动权。多角度提升深海实力,以尽快实现“深海开发”。     

Sustainability of deep-sea fisheries

As coastal fisheries around the world have collapsed, industrial fishing has spread seaward and deeper in pursuit of the last economically attractive concentrations of fishable biomass. For a seafood-hungry world depending on the oceans' ecosystem services, it is crucial to know whether deep-sea fisheries can be sustainable.The deep sea is by far the largest but least productive part of the oceans, although in very limited places fish biomass can be very high. Most deep-sea fishes have life histories giving them far less population resilience/productivity than shallow-water fishes, and could be fished sustainably only at very low catch rates if population resilience were the sole consideration. But like old-growth trees and great whales, their biomass makes them tempting targets while their low productivity creates strong economic incentive to liquidate their populations rather than exploiting them sustainably (Clark's Law). Many deep-sea fisheries use bottom trawls, which often have high impacts on nontarget fishes (e.g., sharks) and invertebrates (e.g., corals), and can often proceed only because they receive massive government subsidies. The combination of very low target population productivity, nonselective fishing gear, economics that favor population liquidation and a very weak regulatory regime makes deep-sea fisheries unsustainable with very few exceptions. Rather, deep-sea fisheries more closely resemble mining operations that serially eliminate fishable populations and move on.Instead of mining fish from the least-suitable places on Earth, an ecologically and economically preferable strategy would be rebuilding and sustainably fishing resilient populations in the most suitable places, namely shallower and more productive marine ecosystems that are closer to markets.