Current Research

Holly Embke: Walleye, a culturally, economically, and ecologically important sportfish in much of North America, has experienced declines in recent years. The cause of these declines is not understood, but is likely due to a combination of factors, such as temperature changes, harvest, and species interactions. As part of a multi-year project to understand the mechanisms underlying how Walleye are affected by other fishes, we will be conducting an experiment on McDermott Lake. We will remove as many bass and sunfish from this lake as possible to determine if there is an interaction between these fishes and walleye.

Dr. Gretchen Gerrish: I am an evolutionary ecologist that studies how organisms adapt to changing ecological conditions. My research focuses on aquatic invertebrates with unique life cycles and reproductive strategies that allow them to survive in variable environments. Currently, I am investigating how vertical migration behavior in zooplankton changes in relation to moonlight throughout the lunar cycle.

Dr. Susan Knight: Wild rice is an annual grass that grows in shallow water in lakes and slow-moving streams in the Upper Midwest. It is a valuable food source for wildlife and people, but populations of wild rice have been declining in our area. We plan to follow six populations of wild rice; two healthy populations, two populations growing near invasive aquatic species, and two previously healthy populations that have not done well in the last five years.  We will assess variables critical to the health of wild rice through the entire growing season, with special attention to the status of the wild rice seed banks and competing aquatic vegetation.

Dr. Noah Lottig:I am an Assistant Scientist and Site Manager with the North Temperate Lakes Long Term Ecological Research Program. My primary research interests focus around ecosystem ecology and landscape limnology. I am particularly interested in understanding the long-term dynamics of aquatic ecosystems as well as the role aquatic ecosystems play in the regional and global carbon cycle.

Joe Mrnak: Invasive species are a global concern, particularly for aquatic ecosystems.  It remains unknown how food web configuration plays a role in the restoration of native pelagic systems and in the mitigation and control of invasives. We will be conducting two whole-lake experiments to test the hypothesis that food web configuration (i.e., presence or absence of a predator) influences interactions between native and invasive forage fishes.  To accomplish this, we will be stocking native cisco (Coregonus artedi) into Crystal and Sparkling lakes, which are currently dominated by invasive rainbow smelt (Osmerus mordax).  Crystal contains no predator and Sparkling will receive supplemental walleye (Sander vitreus) stocking.  We hypothesize greater rainbow smelt control and cisco reintroduction success in the system with predators (Sparkling) than without (Crystal). This study will have implications for future reintroduction and control efforts.

Charles Olmsted: Microbes dominate most of Earth’s biogeochemical cycles, especially those at work in aquatic ecosystems and doubly so in our LTER study sites, a smattering of bog lakes in northern Wisconsin. Members of the Microbial Observatory (MO), like myself, not only collect microbial samples and physical data for untold future LTER projects, but we also ask specific microbial questions. Our current obsession is Extracellular Electron Transfer (EET), and not just because biologically produced electricity is exciting. EET happens in most ecosystems on Earth, but our bog lakes are highly enriched for EET. One of our many questions is simply: why?

Cheyenne Stratton: Invasive crayfishes are among the most widespread freshwater invaders, causing ecological harm through competition and habitat alteration. Invasive rusty crayfish impact macrophyte, invertebrate, and fish communities at the whole-lake scale. Crayfish can harbor a diverse suite of pathogens, but the potential for these pathogens to mitigate invasive crayfish impacts is not well understood. In 2019, our research team discovered a microsporidian outbreak in rusty crayfish in Trout Lake. We are evaluating the effects of this parasite on crayfish density, behavior, growth, and survival. We will also be examining whether communities impacted by rusty crayfish invasions (e.g., macrophytes, invertebrates, fish) recover as infection alters crayfish density and traits at a lake-wide scale within Trout Lake.

Dr. Carl Watras: We are investigating how lakes respond to changes in atmospheric pollutants derived from fossil fuel combustion. Although emissions of many pollutants have declined over the last 3 decades, the levels of contaminants in regional lakes and lake biota have not responded in kind. Instead, they’ve oscillated with the water cycle in ways that are often counter intuitive. This summer our focus is a sensor network maintained by citizen scientists to track how key elements of the water cycle vary from lake to lake. The goal is a broader understanding of how pollution levels are linked to climate variables.