Deep-Sea Hydrothermal Vent Communities
Deep-Sea Hydrothermal Vent Communities
复制标题
DOI：
--
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
L. Mullineaux
中科院分区：
文献类型：
--
作者：
L. Mullineaux
深海热液喷口的生物群落在沙漠般的深海中形成了绿洲。它们的独特之处在于扩展了我们对生命多样性的理解，它们挑战了生态范式。1977年，深海热液喷口首次在东太平洋被发现。早期的生物学研究主要集中在证明微生物化学自养支持食物网，以及调查物种对极端条件的惊人适应。喷口群落受到物理和化学环境的严格限制，这限制了物种的分布和丰度。无脊椎动物物种的相互作用决定了这些限制范围内的群落组成，其过程与在沿海栖息地观察到的过程类似，但有时会以挑战既定生态理论的方式进行。火山和构造活动可以频繁地在喷口，改变或破坏栖息地和消灭群落。这种干扰使得幼虫交换对维持区域元群落的种群和多样性至关重要。物种分布受到幼虫（和遗传）交换障碍的影响，但干扰引入的随机性使得在不了解其历史的情况下很难预测任何特定喷口的物种组成。对大洋中脊和弧/弧后系统的偏远地区的探索继续揭示新的物种，新的生理和生化适应，以及有趣的群落。我们对这些系统还远远没有完全了解，但随着金属供应的减少和价格的上涨，海底热液喷口的开采已经成为现实。预测人类干扰对喷口群落的影响是一项挑战，需要仔细应用我们目前基于野外和理论的对其元群落动态的理解。深海动物在许多方面与沿海栖息地的动物不同；也许没有比深海热液喷口以化学合成为基础的群落更独特和迷人的了。1979年，科学家首次在靠近Galápagos群岛的东太平洋深处描述了喷口群落，在那里科学家报告了长达3米的无胆无口管虫，以及与富含化学物质的海底温泉有关的各种其他生物（Corliss et al. 1979）。这些生物在大部分食物匮乏的深海中形成了生物生产的绿洲（图17.1）。最初的困惑是，在一个食物被认为完全由表面浮游生物的残骸提供的系统中，这种生产是如何维持的，这些浮游生物在沉入海底时逃脱了消耗。对管虫（Cavanaugh et al. 1981），以及后来对喷口蛤、贻贝和多毛类（Van Dover 2000）的研究发现，共生细菌使用还原化学物质产生有机碳。这些细菌和其他自由生活的微生物在排气系统中支持一个由化学合成驱动的生态系统，而不是为几乎所有其他海洋和陆地群落提供基础的光合作用过程。C
ommunities at deep-sea hydrothermal vents form oases in the desert-like deep sea. They are unique in ways that extend our understanding of the diversity of life, and they challenge ecological paradigms. Deep-sea hydrothermal vents were fi rst described in 1977 in the eastern Pacifi c. Early biological studies focused on demonstrating that microbial chemoautotrophy supported the food web and on investigating the striking adaptations of species to extreme conditions. Vent communities are tightly constrained by the physical and chemical environment, which sets limits on species’ distributions and abundances. Invertebrate species interactions determine community composition within these limits through processes that parallel those observed in coastal habitats, but sometimes in ways that challenge established ecological theory. Volcanic and tectonic activity can be frequent at vents, changing or destroying habitat and eliminating communities. This disturbance makes larval exchange critical for maintenance of populations and diversity in the regional metacommunity. Species distributions are infl uenced by barriers to larval (and genetic) exchange, but the stochasticity introduced by disturbance makes it diffi cult to predict the species composition at any particular vent without knowing its history. Exploration of remote areas of mid-ocean ridge and arc/back-arc systems continues to reveal new species, novel physiological and biochemical adaptations, and intriguing communities. We are far from a full understanding of these systems, but as supplies of metals dwindle and prices increase, seafl oor mining at hydrothermal vents has become a reality. Predicting the effect of human disturbance on vent communities is a challenge that requires careful application of our present fi eld-based and theoretical understanding of their metacommunity dynamics. Deep-sea faunas differ in many ways from those in coastal habitats; perhaps none are more unique and fascinating than the chemosynthetically based communities at deep-sea hydrothermal vents. Vent communities were fi rst described in 1979 from the deep eastern Pacifi c near the Galápagos archipelago, where scientists reported on gutless, mouthless tubeworms up to 3 m in length, along with a variety of other organisms, in association with chemical-rich seafl oor hot springs (Corliss et al. 1979). These organisms formed oases of biological production in the mostly food-poor deep sea (Figure 17.1). The initial puzzle was how this production was sustained in a system where food was thought to be supplied solely by the remains of surface plankton that escaped consumption as they dropped to the seafl oor. Examination of the tubeworms (Cavanaugh et al. 1981), and later of vent clams, mussels, and polychaetes (reviewed in Van Dover 2000), revealed symbiotic bacteria that use reduced chemicals to produce organic carbon. These bacteria and other free-living microbes in the vent system support an ecosystem fueled by chemosynthesis, rather than by the photosynthetic processes that provide the basis for virtually all other marine and terrestrial communities. C