Fish Ecology Field & Laboratory Assistant

Employer:  Joe Mrnak ( (he/him/his)

Description:  Invasive species are a global concern, particularly for aquatic ecosystems.  In Wisconsin, invasive rainbow smelt (Osmerus mordax) negatively affect ecosystems that they colonize, primarily through competitive and predatory interactions with native species.  Negative effects include shifting food webs, altering zooplankton communities, and the decline or extirpation of native cool- and cold-water fishes (e.g., yellow perch Perca flavescens, walleye Sander vitreus, cisco Coregonus artedi).  Understanding and mitigating these effects and associated consequences are of primary interest to managers and ecologists alike. Research will focus on characterizing the abundance, distribution, diets, and population dynamics of several fish species during two whole-lake experiments.  The work will primarily be composed of;

Field work:

  • ~67% of time (work will be conducted BOTH during the day and at night)
    • Hydroacoustic fishery surveys
    • Fish sampling (e.g., vertical/horizontal gillnets, fyke nets, boat electroshocking, etc.)
    • Fish processing (length, weight, sex, diets, age structures, isotopes, etc.)
    • Basic limnological and zooplankton sampling

Laboratory work:

  • ~33% of time
    • Sample processing (e.g., fish diets, age structures, zooplankton, isotopes, etc.)
    • Data entry

Most of the work will be based in the field and may require long hours under sometimes adverse conditions.  Fish sampling and habitat characterization will all be done via boat.  Technicians will gain experience with several fish and limnological sampling methods.

Having students with different life experiences and backgrounds is critical to ensure the exchange of diverse ideas that is called for in training tomorrow’s scientists. Because we are actively working to increase diversity and inclusivity in our discipline, underrepresented groups are especially encouraged to apply.


  • Safe operation of UW – Madison boats and vehicles
  • Launching and towing boats
  • Careful and accurate data collection, sample processing, and data entry
  • Deploying and retrieving fish equipment
  • Handling and collecting data from various fish species
  • Assist with field and lab equipment maintenance


  • Must be eager to learn and have a genuine interest in aquatic ecology and(or) fisheries management
    • An aspect of this position will be an opportunity to conduct an independent research project (including giving an oral presentation) using data you collected
  • Maintain positive attitude while conducting work
  • Must be willing to work under sometimes adverse conditions (i.e., hot sun, cold, wind, rain, biting flies, etc.) for long hours
  • Be able to lift and carry a moderate amount (~30-50 lbs) of gear over short distances
  • Must be able to swim
  • Valid driver’s license which meets UW Risk Management standards is preferred.


  • Number of positions: 2 @ ~30-40 hrs/week
  • Start date: mid to late May 2020
  • End date: end of August 2020
  • Pay:  $11.25-no experience; $11.50-some experience; $11.75-very experienced


These positions are located at the CFL’s Trout Lake Station in Boulder Junction, WI in northern Wisconsin.   Dormitory style housing (not food) is provided free of charge. Enjoy swimming, hiking, fishing, biking and shoreline campfires while gaining valuable research experience!

How to apply:

The CFL is an equal opportunity employer and is dedicated to an inclusive and positive working environment for all.