Mechanical imitation of bidirectional bioadvection in aquatic sediments
Mechanical imitation of bidirectional bioadvection in aquatic sediments
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水生沉积物中双向生物平流的机械模拟
DOI：
10.4319/lom.2011.9.84
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
S. Woodin
中科院分区：
文献类型：
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作者：
G. Y. Matsui;N. Volkenborn;L. Polerecky;U. Henne;D. Wethey;C. R. Lovell;S. Woodin
由于动物活动的不可预测性，测量生物灌溉动物群对沉积物性质和地球化学的影响通常是有问题的。这可以通过使用以受控和可重复的方式模拟生物灌溉的机械系统来克服。逼真的模拟必须允许对复杂的动物活动进行定性和定量模拟，即使用生物学上真实的水体积在真实的幅度和频率范围内生成正和负孔隙水压力波形。我们开发了一种满足这些标准的机械灌溉系统 (Robolug)，并用它来模仿沙蚕滨海沙蚕的一系列特定水力行为。由此产生的孔隙水压力波形具有真实的形状和幅度，并且是通过泵送生物学真实体积的水来实现的。由双向生物平流引起的深度和沉积物水界面的孔隙水流动模式与活体沙蚕观察到的情况相当。此外，我们能够重现沉积裂缝的形成，这种现象也在真实的沙蚕身上观察到。 Robolug 灌溉系统是广泛的生物地球化学和生态研究的一个有前景的工具，因为它 (1) 允许以受控和可重复的方式探索生物水力引起的沉积物完整性破坏和瞬态地球化学条件； (2)避免动物表现的不确定性； (3) 允许可能对生物体有害或改变其行为的操纵性实验条件； (4) 允许研究与生物水力学行为相关的能量需求。
Measuring the effects of bioirrigating infauna on sediment properties and geochemistry is often problematic due to the unpredictable nature of the animal activity. This can be overcome by the use of mechanical systems that mimic bioirrigation in a controlled and reproducible manner. A realistic mimic must allow both qualitative and quantitative imitation of the complex infaunal activities, i.e., generate both positive and negative porewater pressure waveforms in a realistic range of amplitudes and frequencies using biologically realistic water volumes. We developed a mechanical irrigation system (Robolug) that meets these criteria and used it to mimic a set of specific hydraulic behaviors of the common lugworm Arenicola marina. The resultant porewater pressure waveforms had realistic shapes and amplitudes and were realized by pumping biologically realistic volumes of water. The porewater flow patterns at depth and at the sediment water interface, induced by bidirectional bioadvection, were comparable to those observed with live lugworms. Additionally, we were able to reproduce the formation of sedimentary cracks, a phenomenon also observed with real lugworms. The Robolug irrigation system is a promising tool for a wide range of biogeochemical and ecological studies, as it (1) allows the exploration of bio‐hydraulically induced disruption of sediment integrity and transient geochemical conditions in a controlled and reproducible manner; (2) avoids the uncertainties of animal performance; (3) permits manipulative experimental conditions that could potentially be harmful for organisms or alter their behaviors; and (4) allows for the investigation of energy requirements associated with bio‐hydraulic behaviors.