Dr. Jeannette Yen, Professor, and Dr. Marc Weissburg, Assistant Professor, were just awarded a grant from Office of Naval Research entitled, "Fluid Mechanical and Chemical Cues in Thin Layers: Role in Organizing Zooplankton Aggregations".

Abstract: We propose to examine the conditions that are conducive to the formation of plankton aggregations to help address the prevalence and importance of thin layers in the world oceans. The goals of the proposed laboratory experiments are to define the mechanisms by which zooplankton may be attracted to thin layers, and to determine which properties of thin layers evoke the orientation response of copepods. The proposed experiments in our newly constructed salt-water flume target naturally-occurring strain rates, velocity differentials, and shear layer thickness (in situ information will be provided via collaboration with Cowles et al.). Target zoo/phyto-plankton species are those observed in thin layers, and chemical cues will match phytoplankton species and concentrations observed in situ.

A series of experimental treatments are planned to isolate the chemical and hydrodynamic signals that induce zooplankton orientation. The anticipated outcomes of the proposed research include: 1) improved understanding of formation and persistence of thin layers and zooplankton aggregations; 2) better appreciation of the balance between physical forcing and biological responses in thin layer formation; 3) data on zooplankton responses that are required for individual-based models of aggregation to thin layer signals; 4) provide information to field studies about the range of physical measurements that must be performed in order to characterize thin layers and to evaluate their spatial and temporal persistence; and 5) help to target field sites having these features by determining thresholds at which relevant signals induce aggregations.