1 Plankton Patch Feasibility Experiments

Efforts this year focused on testing our model of the effects of episodic increases in current shear on the dynamics and impacts of thin layers of phytoplankton and zooplankton. Thin layers are plankton patches that range in thickness from a few tens of centimeters to a few meters, yet can be sufficiently intense to affect biological rate processes and the performance of current and planned Navy optical and acoustical sensors. Although there is increasing evidence that thin layers can occur in a variety of stratified coastal systems, we know little about their temporal/spatial extent or the mechanisms that control their dynamics. Our primary objectives this year were to (1) quantify the temporal and spatial scales of thin layers of phytoplankton and zooplankton, (2) test our model of the effects of episodic increases in current shear on thin layer formation, maintenance and dissipation, (3) test the hypothesis that zooplankton aggregate into thin phytoplankton layers, and (4) obtain a qualitative picture of circulation in East Sound and its response to large scale forcing.