2019 Lake Superior Freshwater Fellow

When you’re searching for a creature with a name like the bloody red shrimp, you never know what adventures await. For inaugural Freshwater Fellow Jenny Sherren, a UMD Environmental Science senior, those adventures included waking up at 3:00 am for many weeks during the summer of 2019 to pull zooplankton traps from the water, turning the back of her car into a mini field laboratory, and spending countless hours squinting into microscope looking at thousands of tiny organisms. Would any of them turn out to be the invasive Hemimysis anomala?

Jenny’s self-designed project involved testing the value of a low-cost, light-based zooplankton trap design that had proven to be effective at capturing bloody red shrimp where their populations had established in New York. Jenny collaborated with researchers both near and far to source the knowledge, equipment and analysis techniques she needed to test the effectiveness of these traps in the Superior Harbor, where the invasive bloody red shrimp had previously been found but are not currently established. The organism takes refuge in the cracks and crevices of hardened shorelines. Jenny speculated that the many docks, break walls, and rip rap shorelines of the Superior Harbor could provide ideal habitat for the tiny aquatic invader.

A light-based trap is simple in concept: a flashlight affixed inside a canister lures zooplankton through a funnel shape, with a small opening covered by a mesh screen. In reality, perfecting the trap design took much experimentation and many trips to the hardware store! Providing an effective and continuous light source proved to be especially challenging. After many trial and error configurations, Jenny was able to rig up not only an effective trap, but also a weight and stabilization mechanism that kept the traps stable and continuously oriented toward the shoreline.

After successfully negotiating access to trap sites with several different landowners, it was time to search for Hemimysis in the harbor. For a month, Jenny was up before the dawn many times per week setting six different traps, collecting samples, emptying trap contents into jars and resetting them. And then, the real work of sorting through thousands of tiny organisms under the microscope began! In her research, Jenny found that the traps did not detect Hemimysis anomala, but were effective at trapping other non-native zooplankton species and captured a significantly different sampling of organisms than a plankton tow method. As bloody red shrimp continue to be found in other locations in the Superior Harbor, future light-based trap refinements and deployments could be an opportunity for further testing and research.

From the start of her Fellowship tenure, Jenny showed time and again that she is a tenacious problem-solver, a detail-oriented scientific thinker – and a natural-born educator! Not only did she present her research at a statewide fisheries conference, Jenny also shared her research and her Fellowship experience with people of all ages at Reserve events like Lake Superior Day and the RiverTalks science café series. In addition to a poster, Jenny produced a step-by-step User Guide for those interested in applying her design and techniques to their own research. Her experience at Lake Superior Reserve exposed Jenny to many jobs opportunities in the field that she hadn’t considered before – and taught her that her future career path probably includes a healthy mix of research, monitoring and outreach.

As for Lake Superior Reserve, our staff consider ourselves incredibly lucky to have had Jenny on our team for a little over a year. She truly kicked off our Freshwater Fellowship in outstanding fashion!