Office of Undergraduate Research

Fluid Dynamics & Biomechanics: Observing Zooplankton Behavior in the Presence of Micro Oil Droplets

Aquatic Food Web - fresh and marine water are the biota of micro-zooplankton feeding on algae and other suspended particles. Zooplankton, such as copepods and daphnia, act in turn as food sources for fish and other marine life. Hence they are an important link within the food web. During oil spills microdroplets are among the suspended particles. These microdroplets are generated by a variety of processes including: water turbulence, temperature and pressure changes, and chemical dispersion. Their presence has been suggested to affect the behavior of micro-zooplankton, primarily in swimming and feeding mechanics.

Challenge - for controlled experimentation on such effects of oil spills, researchers need arrays of microdroplets of consistent diameter and composition. In the past, laboratory protocols allowed only for inconsistent droplet assemblages. However, the technology of microfluidics could be engaged to produce desired assemblages which in turn can be introduced to simulated zooplankton environments.

Approach - microfluidics is the study of fluid dynamics at the microscopic level with applications ranging from biomedical engineering to environmental monitoring. Using microfluidic devices, we will produce monodispersed microdroplets of predetermined size (5-300microns) and frequency. We will harvest droplets of varying oil compositions (mineral, crude, etc.) to study the degree to which they influence the behavior of the animals.

Results - through this cross-disciplinary study, the primary goal of our research is to observe the behavioral responses in the zooplankton. First, we focus on the engineering design of the apparatus and systems. Second, with digital in-line holography we recorded animal behaviors. Third, post reconstruction allowed us to focus on the animals throughout the vessel. Below are selected figures from our experiments; videos may be found online at

Tasks and responsibilities:

Students will help conduct hands-on experiments in the lab. An interest in experimental fluidic dynamics, biomechanics, optics, and/or oceanography is ideal.

This project is located at the School of Freshwater Science: 600 E. Greenfield Ave. Milwaukee, WI 53204

***Campus Shuttle Service to The School of Freshwater Science is now available!***