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The Lake Guardian

The RV Lake Guardian is the largest Great Lakes' research and monitoring vessel owned by the U.S. Environmental Protection Agency; it is the only self-contained, non-polluting research vessel on the Great Lakes. The Great Lakes National Program Office, located in Chicago, manages it. A professional marine contractor operates and manns the vessel.

The Lake Guardian collects samples of the water, marine life, sediments, and air twice a year, once in spring and summer. These samples provide information that measures the health of the Great Lakes, using state-of-the-art information collection methods and instruments during the twice-a-year spring and summer surveys. As an emergency response ship, the Lake Guardian has participated in many emergency response exercises with the U.S Coast Guard, federal, state, and local governments.

For detailed monitoring research information, visit Great Lakes Monitoring Program.

Conduct research on board the Lake Guardian

During monitoring surveys, EPA offers the Lake Guardian as a ship of opportunity to scientists from federal and state government and universities. We especially encourage research compatible with the standard sampling performed at each station (i.e., simple water and/or plankton samples that can be subsequently processed and analyzed).

EPA scientists work with visiting scientists to simplify their sampling and monitoring programs. In addition, EPA scientists work with other federal and state agencies in using the Lake Guardian to collect samples requested by them. The crew operates the equipment, assisting scientists in conducting their research.

The Lake Guardian supports a number of projects every year:

  • Research requests for projects funded by USEPA have the highest priority,
  • Other projects related to EPA’s work receive the second highest priority, and
  • Projects funded by outside agencies receive third highest priority. 

To request time aboard the Lake Guardian first contact Eda Lam (lam.eda@epa.gov), 312-353-1739.

When the Lake Guardian’s chief scientist approves your research project, you will need to submit a survey plan. In addition, scientists conducting research aboard the Lake Guardian are required to view the video Safety aboard the Lake Guardian.

Surveys on board the Lake Guardian

EPA evaluates physical, chemical, and biological characteristics of the water column at each of the 8-20 sampling stations. A survey involves sampling a standard set of limitations using several methods:

  • Conducting a conductivity, temperature, depth (CTD) cast
  • Collecting water samples from several depths
  • Towing a plankton net to collect biological samples
  • Periodically collecting sediment for benthic community analyses

Scientists often measure additional limitations in response to unique environmental conditions, such as low dissolved oxygen that is seasonally present in Lake Erie.