New robotic lake-bottom laboratories will be used to help researchers at the University of Michigan monitor western Lake Erie’s cyanobacteria bloom. One is a mobile lab housed in a cigar-shaped autonomous underwater glider. Scientists also are searching for previously unknown toxins in the bloom as well as compounds that could serve as sources of new medicines.
A team from the university’s Cooperative Institute for Great Lakes Research (CIGLR) and the National Oceanic and Atmospheric Administration (NOAA) field tested an environmental sample processor (ESP) in fall 2016 in the lake and deployed it for regular service in July 2017.
The $375,000 ESPniagara sits on the lake bottom and tracks levels of dangerous toxins produced by cyanobacteria. The lab was positioned several miles west of the city of Toledo’s water intake, where it could provide about a day’s notice if highly toxic water was heading toward the intake. The lab was tested and positioned in response to the 2014 Toledo water crisis.
Two more labs – ESPrush and ESPnessie – will enter service this summer. Funding was provided through the federal Great Lakes Restoration Initiative and Great Lakes Observing System.
The three labs will rotate so two are always in the lake during the summer, providing uninterrupted data collection during bloom season, and the first of the two new ESPs is scheduled for deployment this week near the city of Monroe’s water intake, according to Tom Johengen, associate director of CIGLR, which is based at U-M’s School for Environment and Sustainability.
The research team is also testing a roving underwater lab in western Lake Erie for 10 days in mid-August. The AUV glider is about 7 feet long, 2 feet in diameter, and is shaped like a cigar. It will cover about 25 miles per day. The lab will collect data about the harmful algal bloom (HAB) including toxin concentrations as well as genetic and environmental information.
The rover has mobile 3G-AUV technology that is being developed in partnership with CIGLR, NOAA’s Great Lakes Environmental Research Laboratory in Ann Arbor, the Monterey Bay Aquarium Research Institute, and the University of Washington.
“NOAA is developing this autonomous technology to enable persistent, 24/7 detection and mapping of HAB toxins,” says Steve Ruberg, observing systems researcher at NOAA’s Ann Arbor lab who is leading the development of the Mobile 3G-AUV technology.
CIGLR and NOAA researchers also maintain eight monitoring stations in Lake Erie’s western basin. Water samples are collected weekly throughout the summer to study bloom development, spatial extent, duration, and termination.
In related news, U-M researchers are collecting and analyzing samples from the cyanobacteria bloom to discover and characterize previously unknown toxins that may threaten human health as well as compounds that could serve as sources of new medicines.
The study is part of the new Great Lakes Center for Fresh Waters and Human Health, which is led by Bowling Green State University and founded last year with a $5.2 million federal grant. It is led by Greg Dick, microbiologist and oceanographer at U-M, and David Sherman, professor of medicinal chemistry who studies natural compounds made by microorganisms.
“Our role is to apply techniques in environmental genomics and the biochemistry of natural products to study Lake Erie cyanobacterial blooms in order to identify new toxins, and also compounds that are of potential use for medicine,” says Dick, an associate professor in the U-M Department of Earth and Environmental Sciences.
The cyanobacterium Microcystis is commonly found in Lake Erie algal blooms and produces a class of toxins called microcystins that post a threat to human and animal health. More than 50 have been discovered worldwide to date.
The project will identify genes responsible for the production of previously unknown toxins in the lake’s blooms, as well as bioactive compounds that could be targeted for further study as disease treatments.
“DNA will be isolated, sequenced, assembled from samples, and analyzed by Greg’s group. This will tell us what types of microbes are present and how the bloom composition changes over the course of the summer and fall,” says Sherman, a research professor at U-M’s Life Sciences Institute. “My group will determine the complexity of known microcystin toxins and identify new toxins. Together, we hope to understand how blue-green algae blooms change over time, the parameters that may impact toxin production, the source of the toxins, and the mechanisms behind any changes that we observe.”
