The inhalant siphon flows produced by benthic invertebrates such as clams through suspension feeding and respiration can directly affect a wide range of physical and chemical processes in benthic marine ecosystems. This process is energetically costly and influences the feeding and reproductive biology of the individual. Moreover, understanding siphon flows at multiple scales are widely used not only to address questions of flow fields for other aquatic organisms and exchange processes, but have direct impacts on a variety of engineering problems such as designing sewers. Despite the importance of these flow fields in biology, relatively little research has been conducted on this topic. For this study, the PIs have modeled the flow outside the siphon entrance of several important benthic marine and have found radically different results from those commonly assumed. Given these findings, the PIs propose to test the results of their numerical simulation on inanimate physical models, and then verify their accuracy using live organisms.
The proposed numerical modeling will examine and predict effects of several parameters including inhalant siphon wall thickness, siphon height, disturbances caused by exhalant flows, and sensitivity to ambient flows. Predictions will be initially tested by using inanimate analog models. To provide a broad ecological framework, the PIs will then focus on five model suspension feeders, each of which have been extensively studied, and include a species of benthic shrimp, a tunicate, a soft shelled clam, the parchment worm, and a tube dwelling amphipod. This suite species will provide a broad description of the intake flow as each feeding system span nearly all the range of Reynolds numbers observed in animals that produce siphon flows. The results of this study will improve our current understanding the effects of organismal intake flows on near bed processes such as vertical fluxes of organic and inorganic nutrients, an important aspect of benthic ecology. Direct deliverables will include verified quantitative models of inhalant flows of marine benthos, connecting form and function and detailing fluid mechanical costs of operation.
The PIs will partner with the staff of Centers for Ocean Sciences Education Excellence (COSEE) to produce a pair of educational webinars on fluid flows. This series of webinars are targeted toward high school teachers and university professors, and will use concept maps to demonstrate how mathematics, biology, and fluid dynamics can be integrated to answer broad oceanographic questions. Both PIs will continue graduate training in interdisciplinary science and will incorporate examples of the proposed work in their undergraduate and graduate teaching.
