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  2. Great Lakes Monitoring

Great Lakes Mysis Monitoring

On this page:

  • What are Mysis?
  • Why does GLNPO monitor Mysis?
  • How does GLNPO sample and analyze Mysis?

What are Mysis?

Mysis are a type of crustacean, similar to shrimp, that feed on zooplankton and phytoplankton. Mysis are sensitive to light and temperature, staying in deeper waters during daylight to avoid being eaten and migrating up at night in the water column to feed. Mysis diluviana are the species found in the Great Lakes.

Mysid
A Mysid, usually 1-2cm in length (Image from NOAA GLERL)

Why does GLNPO monitor Mysis?

Mysis are an important part of the Great Lakes food web.  They eat phytoplankton and zooplankton, and Mysis serve as a food source for Great Lakes fish. Mysis also compete with fish for their zooplankton and phytoplankton food source.

How does GLNPO sample and analyze Mysis?

Aboard the R/V Lake Guardian, Mysis are collected at night by a full depth net tow using a mysid net. During the net tow, lights are turned off to maintain the dark environment and avoid disturbing the Mysis while scientists use red lights to conduct the sampling. Once collected, the Mysis sample is used to evaluate population size, organism size, and reproductive status of the Mysis in each lake.

Scientists collecting Mysis from the net tow
Scientists, in the glow of red lights on deck, collect the mysid net tow from aboard R/V Lake Guardian 

Great Lakes Monitoring

  • Great Lakes Monitoring
    • Great Lakes Water Quality Monitoring Program
    • Integrated Atmospheric Deposition Network
    • Great Lakes Biology Monitoring Program
    • Great Lakes Fish Monitoring and Surveillance Program
  • EPA's Research Vessel Lake Guardian
  • Great Lakes Coastal Wetland Monitoring Program
    • Why Monitoring of the Great Lakes Coastal Wetlands is Important
    • How the Great Lakes Coastal Wetlands are Monitored
    • Where Great Lakes Coastal Wetlands Occur
    • Great Lakes CWMP Results and Major Findings
    • How the CWMP Data are Being Used
  • Cooperative Science and Monitoring Initiative (CSMI)
    • About Cooperative Science and Monitoring Initiative (CSMI)
    • 2021 Surveys Conducted on Lake Guardian
    • 2019 Surveys Conducted on Lake Guardian
Contact Us About Great Lakes Monitoring
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on February 21, 2025
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