Two bright orange, solar-powered sailing vessels will launch from Ashland this week on a mission to study the changing fish populations in the Apostle Islands and across Lake Superior. One goal is to better track the sustainability of lake trout populations, by gathering more precise data about the prey fish the trout eat.
Saildrones being assembled at the Great Lakes Science Center Ashland Biological Station dock – Dave Olson photo
The US Geological Survey (USGS) says the month-long fisheries science mission will involve two uncrewed saildrones from Saildrone, Inc., and two two long-range autonomous underwater vehicles (LRAUVs) developed by the Monterey Bay Aquarium Research Institute in California.
Saildrone under way – photo from Saildrone, Inc.
Monterey Bay Aquarium Research Institute LRAUV collecting hydroacoustic data on Lake Michigan in 2016. – public domain photo
The 23-foot-long saildrones are propelled by the wind and guided by computer with oversight from remote operators. The onboard research equipment is powered by solar arrays on the boat and sail. Sonar equipment (essentially scientific-grade fish finders) will estimate fish populations and biomass in the Apostle Islands and elsewhere in Lake Superior. The saildrone data and data from the underwater vehicles, will be compared to data collected during recent lake-wide hydroacoustic surveys using the 107-foot USGS research vessel Kiyi.
File video from Saildrone, Inc.
The USGS says the second saildrone will be part of “overtake experiments” where boats from various agencies will follow the same track as a saildrone on the same night to measure the distances at which vessel noise scares fish away. Six different research vessels operated by the USGS, the states of Minnesota and Wisconsin, the Grand Portage and Red Cliff Bands of Lake Superior Chippewa, and the Province of Ontario will be part of the mission.
Locations in Lake Superior targeted for data collection using remotely-crewed and autonomous vehicles. Black lines indicate intended data-collection transects while yellow boxes indicate areas where a crewed vessel will “overtake” a saildrone while each is collecting data. – USGS Map
The USGS tracks populations of prey fish species including cisco, whitefish and rainbow smelt every year. Changes to these populations affects lake trout populations.
By comparing fish densities measured using the very quiet saildrones to the fish densities measured using much louder conventionally powered vessels, the mission team will learn how vessel noise influences fish distributions during hydroacoustic surveys. Increasing the accuracy of future prey fish counts should lead to more effective fishery management.
The scientific mission will begin with a ceremony on Tuesday, August 9th in Ashland, hosted by the USGS and the Great Lakes Fisheries Commission (GLFC). Scientists and other leaders from the USGS, the GLFC, Saildrone, Inc., Monterey Bay Aquarium Research Institute, partner agencies and elected officials are scheduled to attend:
- U.S. Congressman Tom Tiffany
- Tanya Trujillo, Assistant Secretary for Water and Science, U.S. Department of the Interior
- Anne Kinsinger, Associate Director, USGS Ecosystems Mission Area
- Robert Lambe, Executive Secretary, Great Lakes Fisheries Commission
- Russell Strach, Director, USGS Great Lakes Science Center
Given the nature of the mission, the US Coast Guard asks boaters to stay at least 1/3 mile or 500 meters away from the saildrones to avoid interfering with the data collection and to avoid any collisions. The saildrones will be gathering data on Lake Superior through the end of September, when they will return to Ashland.
See our earlier coverage here.
If you like reading stories like this, please consider becoming a Friend.
Jon Okerstrom is a Friends of the Apostle Islands National Lakeshore board member and digital and social media volunteer with a background in digital and television journalism, photography and graphic design.
