Investigating nearshore and offshore patterns of thermocline and deep chlorophyll maxima formation in Lake Ontario

Sturgeon on Cisco June 2021
RAEON’s Slocum glider, Sturgeon, on DFO’s research vessel, Cisco. Photo credit: DFO

Continuous monitoring will provide data needed to help protect ecosystems

Scientists deployed an autonomous underwater vehicle to continuously collect high-resolution spatial and temporal data in Lake Ontario to better understand key lake processes, including currents, primary productivity, and the distribution of phytoplankton and zooplankton. The vehicle, a Slocum glider, is able to collect data 24 hours a day while moving through the western basin of the lake, providing a much more comprehensive dataset compared to other sampling methods. The glider is also gathering data on the deep chlorophyll layer which plays a critical role in food webs and energy transfer within the lake, a process that requires more study and better understanding. Scientists launched the first of three planned Slocum glider missions in late June 2021; future missions are planned over the next several months, and this work will continue over the next few years.

The data collected will help protect valuable ecosystem services in Lake Ontario. Daily, monthly, and seasonal data collected across space and time will improve understanding of lake processes and lead to better models for predicting change, particularly related to climate. Ultimately, this information will contribute to improved management. For example, the base of the food web in the lake supports the $70-million a year salmonid fishing industry. The results also have implications for ensuring water security – Lake Ontario provides an important source of drinking water to the Greater Toronto Area.

Fisheries and Oceans Canada (DFO) is providing logistical support and partial funding under a collaborative agreement with the University of Windsor and RAEON. This project marks the first time Canadian scientists are using gliders to collect this type of data in Lake Ontario.

Flight path of RAEON’s Slocum glider, Sturgeon, in Lake Ontario from June 28 – July 2nd, 2021. Sturgeon remained in the water until July 9th to collect environmental data for DFO scientists in the first of three planned missions.
Snapshot of data collected in Lake Ontario by RAEON’s Slocum glider, Sturgeon, over four dive profiles on July 2nd, 2021; data includes measurements of depth (blue), dissolved oxygen (green), and water temperature (red) and will help in better understanding lake processes.

Other RAEON Projects


Inland Lakes

Lake Erie

Huron-Erie Corridor

St. Lawrence River

Lake Superior

Lake Ontario

Lake Huron

Lake Michigan

Projects to Come

Rideau Canal Waterway

Lake Winnipeg

Get In Touch

    Great Lakes Institute for Environmental Research
    University of Windsor
    2990 Riverside Drive West
    Windsor, Ontario, N9C 1A2