Research Vessel Lake Guardian

R/V Lake Guardian

At 180 feet and displacing 850 tons, the research vessel Lake Guardian is largest Great Lakes research and monitoring vessel owned by the U.S. Environmental Protection Agency (EPA). The Lake Guardian is operated by the EPA's Chicago-based Great Lakes National Program Office, conducts monitoring programs that sample the water, aquatic life, sediments, and air in order to assess the health of the Great Lakes ecosystem.  The ship is equipped with state-of-the-art data collection techniques and instruments for use during biannual spring and summer surveys.

Science and Research Support

The chemistry lab on the R/V Lake Guardian.

The chemistry lab on the R/V Lake Guardian.

EPA scientists use the ship primarily to gather chemical and biological data from the Great Lakes, as well as data concerning pollutant concentrations in the water, sediment, air, fish and other organisms. Using the vessel, EPA scientists conduct biannual, month-long monitoring surveys during April and August to collect samples from up to 20 pre-established locations on each lake. Guest scientists are invited on board as space allows.

Lake Guardian is well equipped for conducting a wide range of environmental research and monitoring. The ship supports three interior laboratories—a chemistry lab, a biology lab and a multipurpose lab. Researchers can store samples in a walk-in refrigerator and a walk-in freezer. In addition, the Lake Guardian is fitted with four modular labs that are secured to the ship deck and are customized to accommodate the needs of various research activities.

The Rosette sampler on the R/V Lake Guardian collects water samples from any depth. These samples can then be analyzed in the laboratory for a variety of nutrients and chemicals.

The Rosette sampler on the R/V Lake Guardian collects water samples from any depth. These samples can then be analyzed in the laboratory for a variety of nutrients and chemicals.

The Lake Guardian also is equipped with a “clean room,” which is housed in the chemistry lab. Special air filters, constant positive air pressure and a restricted admittance policy virtually guarantee an uncontaminated environment for storing samples.

A data sonde is used to measure water properties such as depth, temperature, conductivity (which helps to determine salinity), pH, light penetration, water transparency, and chlorophyll content. Another water sampling device, the rosette, captures an exclusive water sample from any desired depth and brings it to the surface. Scientists use the rosette to measure certain parameters of water samples, such as phosphorus and chloride levels.

To collect microscopic biological samples like phytoplankton, scientists aboard the Lake Guardian use plankton nets. Other permanent science devices aboard the Lake Guardian include equipment used to sample air contaminants, a box corer used to take samples from the lake bottom, and a sled-like device that is dragged behind the ship to capture plankton. The ship has several winches for launching a range of scientific equipment.

Navigation and Communications

The Lake Guardian navigates via a Global Positioning System and various tools such as radars, a gyrocompass, fathometers and radios. Ship-to-shore communications aboard the ship include fax via satellite phone, internet access via KVH TracNet and email via SSB HF radio.

This vessel has been operating on the waters of the Great Lakes since 1988. The ship is offshore collecting data for approximately seven months a year. Capable of traveling up to 6,000 miles at a cruising speed of 11 knots, the Lake Guardian can carry a maximum of 27 scientists and 13 crew.


To learn more:

R/V Lake GuardianExternal link, U.S. Environmental Protection Agency Great Lakes National Program OfficeExternal link