Collaborative Research: Studies on the Physiological Ecology of Hydrothermal Vent Chemoautotrophic Symbioses

喷口动物群是一种分布于全球的深海古动物群。它与大多数深海群落在分类学上的亲缘关系有限，但与深海碳氢化合物渗漏和其他渗漏环境的动物群却有亲缘关系。深海热液喷口是地球上主要的生态系统类型之一，但可能是最不为人所知的。这些群落的高生物量在很大程度上反映了少数无脊椎动物/细菌共生体利用周围深海水中的氧气为初级生产提供动力的能力，氧化来自喷口的还原化学物种(硫化物或甲烷)。根据估计的高生物量、喷口群落的快速建立和一些喷口动物的快速生长，人们经常在文献中看到喷口群落具有高生产力的说法。然而，目前还没有关于任何热液喷口共生生物初级产量的有根据的估计。这项研究的中心目标是量化主要喷口共生生物与喷口流体的化学相互作用以及这些共生生物的丰度，以便可以为共生动物的整个集合模拟初级和次生生产以及其他化学交换。这涉及确定共生体的生产和交换率的范围，以及环境条件和这些比率之间的关系。然后，环境数据将被用来估计在单个时间点和喷口地点的整个生命周期内整个集合体的就地速率。这首先包括奇尔德里斯小组将其对交换率的研究扩大到所有主要自养共生体的大小范围。作为补充，Fisher小组将对EPR上9‘50’N的位置进行表征和采样，以便记录生物量、生物体丰度和生物体大小，并建立大小/重量关系。这些数据将能够估计整个共生组合的产量，它们还可以与现有的摄影数据集一起用于估计其他EPR地点的生物量，这些地点已经通过摄影记录并存在化学数据集。这一结果将极大地提高对喷口动物与其化学环境之间相互作用的性质的理解，并使人们能够首次可靠地估计喷口群落的共生成分的产量和其他交换，为了解喷口和其他化学自养支持的生态系统的功能做出重大贡献。

Vent fauna is a largely ancient fauna of global distribution in the deep?sea. It has limited taxonomic affinities to most deep?sea communities, and yet it has affinities to the faunas of deep?sea hydrocarbon seeps and other seep environments. Deep?sea hydrothermal vents are one of the major ecosystem types on the earth, but probably the least known. The high biomasses of these communities largely reflect the ability of a few invertebrate/bacteria symbioses to oxidize reduced chemical species (sulfide or methane) from the vents using oxygen from the surrounding deep?sea water to power primary production. The allegation that vent communities are highly productive is often seen in the literature based on the high biomasses estimated, the rapid establishment of vent communities and the rapid growth of some vent animals. However, there are currently no well?founded estimates of primary production by the symbioses at any hydrothermal vents. The central objective of this study is to quantify the major vent symbioses' chemical interactions with the vent fluids and the abundances of those symbioses in such a way that primary and secondary production and other chemical exchanges can be modeled for entire assemblages of symbiotic animals. This involves determining the range of production and exchange rates of the symbioses and the relations between environmental conditions and those rates. Environmental data will then be used to estimate in situ rates for entire assemblages at single points in time and over the lifetime of vent sites. This consists first of the Childress group expanding its study of the rates of exchanges to a range of sizes of all the major autotrophic symbioses. Complementing this, the Fisher group will characterize and sample sites at 9'50'N on the EPR so that the biomass, organism abundance and organism sizes are documented and size/weight relationships are developed. These data will enable the estimating of production in entire symbiotic assemblages and they can also be used with existing photographic datasets to estimate biomasses at other EPR sites which have been photographically documented and for which chemical datasets exist. The results will greatly increase the understanding of the nature of the interactions between the vent animals and their chemical environments and enable the first solid estimates of production and other exchanges by the symbiotic components of vent communities, making a major contribution to the understanding of the functioning of vent and other chemoautotrophically supported ecosystems.