The unmanned vehicles will be busy this summer, covering Lake Erie in their research mission. (USGS)

BY D’ARCY PATRICK EGAN

Boaters and fishermen have been surprised by the appearance of a very quiet, bright orange Saildrone Explorer that has been slowly navigating the waves of the Western Basin of Lake Erie in July and August. The new unmanned Saildrone Explorer has been employed by the U.S. Geological Survey (USGS) to perform fishery surveys like never before.

The Saildrone Explorer is heading to the Central Basin this week, its electronics efficiently monitoring Lake Erie’s fishery in late summer and fall. In the coming weeks it will scan waters off of Huron, Lorain and Cleveland. The Saiidrone Explorer will operate in Lake Erie’s western, central and eastern basins, circumnavigating the lake in a clockwise direction through the end of September.

“This is the first time a long-range wind powered autonomous surface vehicle is being used on Lake Erie,” said USGS Fishery Biologist Dr. Mark DuFour, who is stationed at a new USGS office in Huron, Ohio. “We’re working closely with fishery managers in Michigan, Ohio and New York to promote and improve our Lake Erie fishery.

The U.S. Geological Survey is using autonomous surface and underwater vehicles on Lake Erie, like the Saildrone Explorer, this summer to improve fishery research surveys. (Michael Berlin, Braden McClain, and Bryan Geary for U.S. Geological Survey)

“The Saildrone Explorer is quite unusual, and fishermen and boaters must stay a safe distance away from the vehicle in order to allow it to perform its research mission,” said DuFour.

In addition to the Saildrone Explorer, the USGS will deploy a different unmanned underwater vehicle on Lake Erie in mid-September near Fairport Harbor. The long range autonomous underwater vehicle, or LRAUV, is much longer, and is operated by the Monterey Bay Aquarium Research institute (MBARI). It will travel well under the Lake Erie waves at 5 to 15 meters below the surface.

“These vehicles will be able to record data much more efficiently than typical trawl net surveys that are used by the Ohio Division of Wildlife,” said DuFour.

The Saildrone Explorer and LRAUV are outfitted with environmental sensors, including a fisheries echo sounder, much like an electronic fish finder that many anglers rely on to find schools of fish, baitfish and the changing thermocline. That is the fish-attracting temperature level between warm surface water and cooler bottom waters of Lake Erie.

“Lake Erie is home to a world class fishery and millions of lakeside residents and vacationers,” said David Nihart, Fisheries Management Chief for the Pennsylvania Fish and Boat Commission and Chair of the Lake Erie Committee in a statement.

The project is organized under the Great Lakes Fishery Commission.

The long range autonomous underwater vehicle, or LRAUV, will be launched in September from Fairport Harbor to monitor Lake Erie’s fishery while traveling well under the Lake Erie waves at 5 to 15 meters below the surface. (USGS)

Monitoring Lake Erie fish populations is integral to sustainable management of the recreational and commercial Lake Erie fishery, but fish community changes and dynamic habitat conditions often create monitoring challenges, reported Nihart. Fisheries acoustic surveys on Lake Erie are presently conducted using diesel-powered research vessels that are relatively loud and, as a result, may impact data collected from near-surface and near-bottom fish. The Saildrone Explorer and the LRAUV provide advantages for fishery research that may address these potential biases in existing fisheries acoustic surveys. Saildrones are quieter and may detect more fish swimming closer to the surface than noisy vessels, which may scatter fish.

The LRAUV, which operates in the middle of the water column and has sensors looking up and down, may detect bottom-dwelling and surface-dwelling fish more accurately than traditional fishery research vessels or the Saildrone. Scientists will compare the data gathered using each platform to address potential sampling biases in existing surveys.

The partners will also use the autonomous vehicles to study a variety of other questions on Lake Erie, including the effect of harmful algal blooms on yellow perch in the western basin, detection of large species such as lake whitefish, burbot and lake trout in the eastern basin, and the effect of low-oxygen zones on bottom-dwelling fish in the central basin.

Partners on these studies include the Ohio Department of Natural Resources, Michigan Department of Natural Resources, The Ohio State University, New York State Department of Environmental Conservation, Ontario Ministry of Natural Resources and Forestry, and the Pennsylvania Fish and Boat Commission.

“These experiments using advanced technologies and autonomous vehicles are just one part of a multi-year effort by USGS and fishery management partners across the Great Lakes to improve fishery science in support of the $7 billion Great Lakes fishery,” said Commissioner Jim McKane, chair of the Great Lakes Fishery Commission, in a press release. “This is what 21st Century science looks like, and it’s happening now here in the Great Lakes thanks to strong collaborative partnerships.”