The Role of Biologically Produced Structure in Deep-Sea Community Organization

最近对深海软底层群落的研究表明，物种丰富度受到厘米到毫米尺度的过程的强烈影响，其中许多过程是由生物产生的结构(例如动物管子)控制的。然而，对这种结构在深海群落动态中的作用还没有得到机械性的理解。希斯尔博士和他的合作者埃克曼博士正在评估由多毛类建造的直径2厘米的沉积物结核对圣地亚哥海槽中腕足类丰度的影响机制。特别是，他们的努力将集中在测试对沉积物固结的流体和颗粒动力效应的反应。他们已经使用阿尔文号潜水器对海底的单个沉积物、结核和裸露区域进行采样，并启动了现场实验。他们将完成对前几次巡航中获得的样本的分析。对这些样本的分析将使人们能够确定这些结构所产生的水动力和捕食-避难效应的重要性。前者在深海中可能尤其重要，因为那里的沉积物物理破坏率相对较低。此外，沉积物结核的大小可与其他广泛分布的深海结构物(例如铁锰结核)相媲美。一概而论。

Recent work in deep-sea, soft-substratum communities suggests that species' abundances are strongly affected by processes at centimeter-to-millimeter scales and that many of these processes are governed by biologically produced structures (e.g., animal tubes). However, no mechanistic understanding of the role of such structures in deep-sea community dynamics has been obtained. Dr. Thistle and collaborator Dr. Eckman are evaluating mechanisms by which the 2-cm-diameter sediment concretions built by polychaetes affect harpacticoid copepod abundances in the San Diego Trough. In particular, their efforts will be focused on testing responses to fluid- and particle- dynamic effects of sediment concretions. They have used the submersible ALVIN to sample individual sediment concretions and bare areas of the sea floor and to initiate in situ experiments. They will complete analysis of samples, which were obtained in previous cruises. The analysis of these samples will enable the determination the importance of hydrodynamic and predation-refuge effects created by these structures. The former, in particular, are likely to be especially important in the deep ocean, because of the relatively low rates of physical disruption of sediments there. Further, sediment concretions are comparable in size to other widespread, deep-sea structures (e.g., ferromanganese nodules). generalizable.