Prepared by: Doug Aloisi U.S. Fish and Wildlife Service Kent Bekker Toledo Zoo James Boase U.S. Fish and Wildlife Service Andrew Briggs Michigan Department of Natural Resources Justin Chiotti U.S. Fish and Wildlife Service Matt Cross Toledo Zoo Chris Davis Ontario Ministry of Natural Resources and Forestry Richard Drouin Ontario Ministry of Natural Resources and Forestry James Francis Michigan Department of Natural Resources Dimitry Gorsky U.S. Fish and Wildlife Service William Hintz University of Toledo Darryl Hondorp U.S. Geological Survey Jennifer Johnson U.S. Fish and Wildlife Service Richard Kraus U.S. Geological Survey Christine Mayer University of Toledo John Navarro Ohio Department of Natural Resources Ed Roseman U.S. Geological Survey Brian Schmidt Ohio Department of Natural Resources John Sweka U.S. Fish and Wildlife Service Chris Vandergoot Great Lakes Acoustic Telemetry Observation System Eric Weimer Ohio Department of Natural Resources 2019 Lake Erie Sturgeon Working Group Report This document is intended to provide an update regarding lake sturgeon activities within the Lake Erie basin. Please contact the agency leads listed for more information about a specific project. Location: Southern Lake Huron and Upper St. Clair River Project Title: Lake Sturgeon Population Assessment in Southern Lake Huron Project Description: Southern Lake Huron (Upper St. Clair River) contains one of the largest populations of lake sturgeon in the Great Lakes. In 1995, the Ministry of Natural Resources and Forestry began a mark‐recapture study to gain a better understanding of lake sturgeon population demographics at this location. Tagging operations ceased in 2008. Overall, 1,657 lake sturgeon were marked and it is estimated that the lake sturgeon population is near 30,000 individuals. In 2012, the U.S. Fish and Wildlife Service along with the Ministry of Natural Resources and Forestry and Purdy Fisheries resurrected lake sturgeon tagging operations at this location. Lake sturgeon are tagged annually with the cooperation of Purdy Fisheries. Since 2012, 1,058 sturgeon have been tagged, with 126 tagged in 2019. The goal of this work is to obtain a more precise estimate of lake sturgeon abundance and monitor trends in abundance overtime. Project Duration: Spring 2012 ‐ Annually Contact Information: Justin Chiotti, USFWS, Alpena FWCO ‐ Detroit River Substation, 248‐891‐0087, [email protected] Chris Davis, MNRF, Upper Great Lakes Management Unit ‐ Lake Huron, 519‐371‐8303, [email protected] Location: Southern Lake Huron and Upper St. Clair River Project Title: Lake Sturgeon Gamete Collection in Southern Lake Huron Project Description: Beginning in 2017, the U.S. Fish and Wildlife Service, Ontario Ministry of Natural Resources and Forestry, University of Windsor, and Purdy Fisheries began collecting lake sturgeon gametes in order to stock fall fingerling lake sturgeon in the Lake Erie and Huron basins. The gametes collected will be used to restore the Maumee River, OH and Saginaw River, MI lake sturgeon populations. These lake sturgeon restoration programs are a bi‐national effort between Federal, Provincial, State, and non‐ governmental agencies. The lake sturgeon gametes collected will be reared at either the U.S. Fish and Wildlife Service Genoa National Fish Hatchery or a streamside rearing facility operated along the Maumee River by the Toledo Zoological Society. The upper St. Clair River lake sturgeon population was chosen as the source for this reintroduction effort due to the healthy abundance of lake sturgeon, on‐going monitoring efforts, and it’s genetic similarity to what was historically found in the Saginaw and Maumee Rivers (GSU 1; Welsh et al. 2010). In the spring of 2019, gametes were collected from 8 female and 32 male lake sturgeon. Project Duration: Spring 2017 ‐ Annually Contact Information: Justin Chiotti, [email protected], U.S. Fish and Wildlife Service Doug Aloisi, [email protected], U.S. Fish and Wildlife Service Rich Drouin, [email protected], Ontario Ministry of Natural Resources and Forestry Location: St. Clair River and Lake St. Clair Project Title: Survey of Lake Sturgeon Populations in the St. Clair River and Lake St. Clair Project Description: The Michigan Department of Natural Resources’ Lake St. Clair Fisheries Research Station (LSCFRS) has been conducting lake sturgeon assessment surveys since 1996. Setlines with large and small hooks baited with round goby are used in the St. Clair River to catch juvenile, subadult, and adult lake sturgeon. A custom trawl, designed to ride over vegetation, is used to capture lake sturgeon in the open waters of Lake St. Clair during the summer. Most lake sturgeon captured in Lake St. Clair are subadult or adult size fish. All sturgeon captured are scanned for PIT tags and untagged fish are PIT tagged prior to release. Lake sturgeon over 1,016 mm also receive external Monel tags. The data obtained during these assessments have been used to obtain growth, genetics, distribution, spawning site, and population demographic information. In 2019 we captured a total of 100 unique lake sturgeon during our annual St. Clair River Setline Survey. Of these, 37 were recaptures from previous year’s surveys (37%). Fish caught on setlines ranged from 585 to 1761 mm total length. We captured a total of 44 lake sturgeon during our annual Lake St. Clair trawls that target lake sturgeon. Of these, one was a recapture from previous surveys (2%). Fish caught in trawls ranged from 1041 to 1846 mm total length. Project Duration: 1996 – Present (annually) Contact Information: Andrew Briggs, Michigan DNR, Lake St. Clair Fisheries Research Station, Phone: 586‐465‐4771 ext. 23, [email protected] Project Title: Lake Sturgeon Use of Newly Constructed Artificial Reefs in the St. Clair River and Detroit River Location: St. Clair River and Detroit River Project Description: The USGS Great Lakes Science Center monitored lake sturgeon use of the functional constructed artificial spawning reefs since 2008; two in the St. Clair River at Harts Light and Point aux Chenes and four in the Detroit River near Fighting Island, Grassy Island, Belle Isle, and Fort Wayne (completed summer 2018). Egg deposition upstream, downstream, and on the reefs was assessed using egg mats (all reefs), while larval drift was sampled using benthic D‐ frame and depth‐stratified conical nets upstream and downstream of the reef (Fort Wayne Reef in the Detroit River only). At all reefs, lake sturgeon eggs were not detected during pre‐construction monitoring, but were detected on the reefs immediately post‐construction. In 2019 specifically, lake sturgeon spawning was detected on or near all reefs except Grassy Island and Belle Isle. Larvae were sampled near the Fort Wayne reef from late‐May to mid‐June. Yolk‐sac and post‐yolk sac larvae were collected upstream (9 larvae) and downstream (14 larvae) of the reef, and at the control location (1 larvae downstream of Grassy Island Reef). Egg and larval drift monitoring at the Fort Wayne constructed reef sites will continue in 2020. Project Duration: 2015‐2016 (St. Clair River), 2015‐2020 (Detroit River) Contact Information: Ed Roseman, USGS, Great Lakes Science Center Phone: 734‐214‐7237, [email protected] Project Title: Geographic organization and population structure of lake sturgeon in the Lake Huron‐to‐Lake Erie corridor Location: Detroit‐St. Clair River System; Lake Huron; Lake Erie Project Description This study is using acoustic telemetry to describe the spatial structure and habitat use of lake sturgeon populations that spawn in the St. Clair and Detroit rivers. Since 2011, a total of 282 adult lake sturgeon have been captured in the Detroit and St. Clair rivers, implanted with high‐power acoustic tags with a battery life of 10 years, and then released near the capture site. Strategically‐located acoustic receivers in the Detroit‐St. Clair river system (see map to the right), as well as in lakes Huron and Erie, are allowing scientists to track sturgeon movements over thousands of square miles. Study results have been used to test the hypothesis that a number of separate sturgeon populations occur in the Lake Huron‐to‐Lake Erie corridor rather than one large population. Preliminary results: The most significant finding of the study so far has been the discovery of significant within‐population variability in lake sturgeon migratory behavior (graphic below). Analysis of the movements of 178 individuals over several years identified as many as five distinct migratory strategies or behaviors based on the phenology and duration of river (red) and lake (blue) use. Specific strategies included year‐round river residency and multiple lake‐migrant behaviors that involved movements between lakes and rivers. Individual movements were repeatable, which suggested that lake sturgeon do not switch behaviors. Differential use of specific rivers or lakes by acoustic‐tagged lake sturgeon further grouped individuals into “contingents.” Contingent structure and dynamics suggested that lake sturgeon in the Detroit and St. Clair rivers function as semi‐independent units that require separate management consideration. Limited exchange of spawners between rivers likely prevents the Detroit and St. Clair lake sturgeon populations from becoming genetically distinct. Additional insights provided by the study included 1) the importance of Lake St. Clair as overwintering habitat for lake sturgeon, 2) the potential for complex metapopulation dynamics among lake sturgeon populations