Prepared by members:

Justin Chiotti (Chair) U.S. Fish and Wildlife Service – Alpena FWCO Dave Borgeson Michigan Department of Natural Resources Lori Criger U.S. Fish and Wildlife Service – Marquette Biological Station Chris Davis Ontario Ministry of Natural Resources and Forestry Paul Sullivan Department of Fisheries and Oceans Canada

And non‐members:

Edward Baker Michigan Department of Natural Resources Jim Baker Michigan Department of Natural Resources Darryl Hondorp U.S. Geological Survey – Great Lakes Science Center Serena Lake Lake Superior State University Doug Larson Department of Fisheries and Wildlife – Michigan State University Marlena McCabe University of Windsor Trevor Pitcher University of Windsor Kim Scribner Department of Fisheries and Wildlife – Michigan State University Jeff Speers Ontario Ministry of Natural Resources and Forestry Lexi Sumner Anishinabek/Ontario Fisheries Resource Center

2017 Lake Huron Sturgeon Working Group Report

This document is intended to provide an update regarding lake sturgeon activities within the Lake Huron basin. Please contact the agency leads listed for more information about a specific project.

Location: Black Lake, MI

Project Title: Molecular diet data quantify factors affecting levels of larval lake sturgeon predation by piscivorous fishes in the Black River, MI

Project Description: Predation is a major factor affecting recruitment during early life stages of many fish species. Levels of predation of larval fish have been difficult to quantify using visual observations of gut contents. Development of genetic tools has made predation studies on larval fish more feasible. Potential fish predators of lake sturgeon larvae (N=1155) were collected in four 500‐m stream reaches dominated by sand (N=2) and gravel (N=2) substrates over 17 days during 2015 and 2016. Sampling of larvae dispersing from spawning areas was also conducted to estimate the nightly abundance of larval lake sturgeon and other potential prey (larvae of other fish species and macroinvertebrates) available to predators. Gastrointestinal (GI) tracts of predatory fish were dissected. DNA was extracted from the GI tract contents, and sturgeon‐specific PCR primers that amplify part of the cytochrome oxidase subunit I region of mitochondrial DNA were used to detect the presence of lake sturgeon DNA. Binomial logistic regression was used to assess the relative contributions of biotic (e.g. predator species, biomass of larval sturgeon in the drift) and abiotic variables (e.g. habitat substrate type, lunar phase) to variation in incidences of larval lake sturgeon predation. Metabarcoding using massively parallel sequencing of the 18S gene allowed identification of entire stomach contents, allowing analyses of prey selectivity.

Project Duration: Spring 2015 – present

Contact Information:

Kim Scribner, Department of Fisheries and Wildlife, Michigan State University, 517‐353‐3288, [email protected] Edward Baker, Michigan Department of Natural Resources, 906‐249‐1611, ext 309, [email protected] Doug Larson, Department of Fisheries and Wildlife, Michigan State University, 989‐733‐6176, [email protected]

Location: Black Lake, MI

Project Title: Behavior of juvenile lake sturgeon stocked above a hydropower dam

Project Description Hydropower dams exist on most large Great Lakes tributaries and limit lake sturgeon access to historic spawning and juvenile rearing habitats. Providing lake sturgeon passage (adults upstream and adults and juveniles downstream) is widely believed to be a management action that could improve lake sturgeon rehabilitation in Great Lakes tributaries. However, managers have limited information on the behavior of juvenile lake sturgeon of different ages as they proceed downstream, during times they reside in reservoir habitats above dams or their fate as they pass through hydroelectric facilities. We have tagged (PIT and acoustic) and stocked juvenile (ages 0‐2) lake sturgeon above two hydropower dams in the Black River system and monitored their downstream movement, habitat use, and passage at the dams using passive PIT tag antennas and acoustic telemetry. Survival of fish passing through dams (N=1,569) has been high but variable. Dam passage survival rates ranged from 0.45‐1.0 and were related to fish age (size). Age‐0 fish passage survival estimates ranged from 0.71‐0.90. Fish residence time in reservoirs has varied from a few days to months. We have documented aspects of habitat use and availability in reservoirs and continue with data analysis.

Project Duration: Spring 2014 – present

Contact Information:

Kim Scribner, Department of Fisheries and Wildlife, Michigan State University, 517‐353‐3288, [email protected] Edward Baker, Michigan Department of Natural Resources, 906‐249‐1611, ext 309, [email protected] Doug Larson, Department of Fisheries and Wildlife, Michigan State University, 989‐733‐6176, [email protected]

Location: Black Lake, MI

Project Title: Variation in retention time: how riverine characteristics influence female spawning behavior, reproductive success, and ovarian quality in lake sturgeon

Project Description: Spawning ground surveys conducted in 2012 and 2013 monitoring N=247 and 271, respectively, adult lake sturgeon indicated that females spent between 1 to 23 days on the spawning grounds with 60% of females spending only one day. Retention time (RT, the number of days on the spawning grounds) was influenced by initial arrival date, mean temperature, maximum discharge, and the number of males with the availability of mates having the largest influence. Female reproductive success (RS) determined using genetic parentage analysis ranged from 2 to 38 larvae, and varied due to initial arrival date onto the spawning grounds, mean temperature, maximum discharge, number of males, total length of males, and the operational sex ratio (OSR). Testosterone concentrations quantified in pre‐spawned females to determine ovary quality ranged from 0.29 to 136.94 ng/mL with two fish having levels indicative of atresia in 2013. Both atretic females were assigned larvae during parentage analysis that was below the mean RS. Ovary quality and RS did not vary due to RT. Results indicate that plasticity in the timing of female spawning does not negatively impact RS or ovary quality; however, female RS is largely influenced by environmental conditions and access to mates which are increasingly variable in riverine systems.

Project Duration: Spring 2012 – present

Contact Information:

Kim Scribner, Department of Fisheries and Wildlife, Michigan State University, 517‐353‐3288, [email protected] Edward Baker, Michigan Department of Natural Resources, 906‐249‐1611, ext 309, [email protected] Doug Larson, Department of Fisheries and Wildlife, Michigan State University, 989‐733‐6176, [email protected]

Location: Black Lake, MI

Project Title: Effects of parentage and microhabitat variation within adult‐selected spawning sites on lake sturgeon growth during early life stages

Project Description: Understanding the impact of environmental variation on organismal traits during early life stages is essential for predicting changes in populations. Maternal effects including oviposition site selection are one source of variation. Female choice of sites can vary based on microhabitat variation which directly affects larval development and survival. However, the persistence of microhabitat effects across sequential early ontogenetic stages is limited. In 2013, we collected fertilized lake sturgeon eggs from the Black River, Michigan, just prior to hatch from an adult‐selected spawning location, and quantified three microhabitat variables (water depth, discharge, and substrate size). Larval body length, body area, and yolk‐sac area were quantified at hatch. Body size was measured for an additional four weeks post‐ emergence. Genetic‐based parentage analysis was conducted using fin clips. The traits at hatch varied due to the microhabitat variables, but not due to additive genetic effects. Growth significantly varied among larvae with the greatest range in body size observed at 41 days post‐hatch. Additive genetic variance covaried with age. Narrow‐sense heritability estimates for body length ranged from 0.45 to 0.64. Results demonstrate that female‐selected, microhabitat variation influenced offspring phenotypic variation at hatch, but had no influence on body length at sequential ontogenetic stages. Additionally, the additive genetic effects explained roughly half the variation observed in body size, but individuals showed considerable variation in growth which may be due to differences in the degree of plasticity among individuals.

Project Duration: Spring 2012 – present

Contact Information:

Kim Scribner, Department of Fisheries and Wildlife, Michigan State University, 517‐353‐3288, [email protected] Edward Baker, Michigan Department of Natural Resources, 906‐249‐1611, ext 309, [email protected] Doug Larson, Department of Fisheries and Wildlife, Michigan State University, 989‐733‐6176, [email protected]

Location: Black Lake, MI

Project Title: Factors Affecting Lake Sturgeon Spawning Migration in the Black River, MI

Project Description: Variation in timing of spawning migrations for lake sturgeon (Acipenser fulvescens) and duration of occupancy of spawning areas are often attributed to environmental cues (e.g., temperature, discharge, day length) or biotic (e.g., operational sex ratios). Using several passive detection systems (PIT antenna array), spawning migration data was collected from 341 lake sturgeon river migrations during the 2016 spawning season in the Black River, MI. Data on body size was obtained for a subset of adults upon capture while on the spawning grounds. Timing of migration was most often between dusk and dawn, particularly when spawning density was lowest. Migration timing did not differ between sexes. Multiple intra‐seasonal migration events were undertaken by males and females, contrary to previous reports. Based on Akaike’s Information Criterion, the model that included the largest lag change in water temperature over a 72‐hour period prior to detection at the upstream spawning sites was the best predictor of daily number of migrating of lake sturgeon. Additionally, including the effect of discharge within a 24‐hour lag improved model fit. Results show that lagged effects including increasing temperature and declining discharge strongly impact spawning behavior. Results of duration of migration and occupancy of spawning areas and evaluation of the consequences of variation in migratory behavior to reproductive success are being investigated based on genetic determination of paternity.

Project Duration: Spring 2014 – present

Contact Information:

Kim Scribner, Department of Fisheries and Wildlife, Michigan State University, 517‐353‐3288, [email protected] Edward Baker, Michigan Department of Natural Resources, 906‐249‐1611, ext 309, [email protected] Doug Larson, Department of Fisheries and Wildlife, Michigan State University, 989‐733‐6176, [email protected]

Lake Sturgeon papers by Baker/Scribner Research Group at Black Lake during 2017

Bussy, Ugo, Lydia Wassink, Kim T. Scribner and Weiming Li. 2017. Determination of cortisol in lake sturgeon (Acipenser fulvescens) eggs by liquid chromatography tandem mass spectrometry. J Chromatogrphy B. 1040: 162‐168.

Fujimoto, Masanori, Brian Lovett, Roshan Angoshtari, Paul Nirenburg, Thomas P Loch, Kim T Scribner, and Terence L Marsh. 2017. Antagonistic interactions and biofilm forming capabilities among bacterial strains isolated from the egg surfaces of Lake Sturgeon (Acipenser fulvescens). Microbial Ecology. doi.org/10.1007/s0024.

Baker, Edward, A., and Kim T. Scribner. 2017. Evaluation of Lake Sturgeon Stocking and Estimation of Cohort‐specific First‐ Year Survival in Black Lake, Michigan. Journal of Applied Ichthyology. 33: 892‐897.

Valentine, S., J. Bauman, and K.T. Scribner. 2017. Effects of alternative foods on body size and survival of larval lake sturgeon. North American Journal of Aquaculture. 79: 275‐282.

Waraniak, Justin M., Daniel Blumstein, and Kim T. Scribner. 2017. Effects of changes in alternative prey densities on predation of drifting larval Lake Sturgeon Acipenser fulvescens. Conservation Genetics Resources. doi.org/10.1007/s12686‐017‐0790‐5.

Donofrio, Michael C., Kim T. Scribner, Edward A. Baker, Jeannette Kanefsky, Iyob Tsehaye, and Robert F. Elliott. 2017. Telemetry and Genetic Data Characterize Lake Sturgeon Breeding Ecology and Spawning Site Fidelity in Green Bay Rivers of Lake Michigan. Journal of Applied Icthyology. In press.

Forsythe, P.S., J.A. Crossman, C.P. Firkus, K.T. Scribner, and E.A. Baker. 2018. Predation rates on lake sturgeon eggs by invasive crayfish is related to crayfish density, body size, and substrate size. Journal of Applied Ichthyology. In press.

Crossman, J.A., K.T. Scribner, P.S. Forsythe, and E.A. Baker. 2017. Lethal and non‐lethal effects of predation by native fish and an invasive crayfish on hatchery‐reared age‐0 lake sturgeon. Journal of Applied Ichthyology. In press. 2017;00:1–9. https://doi.org/10.1111/jai.13558.

Jay, K.J., J. M. McGuire, and K.T. Scribner. 2017. Ecological conditions affect behavioral and morphological trait variability of Lake Sturgeon yolk‐sac larvae. Journal of Applied Ichthyology. 2017;00:1–7.https://doi.org/10.1111/jai.13572.

Waraniak, Justin M., Shaley A. Valentine, Kim T. Scribner. 2017. Effects of changes in alternative prey densities on predation of drifting larval Lake Sturgeon Acipenser fulvescens. J. Freshwater Ecology. 32: 619‐632.

Waraniak, Justin M., Edward A. Baker, Kim T. Scribner. Molecular diet analysis reveals predator‐prey community dynamics and environmental factors affect predation of larval lake sturgeon (Acipenser fulvescens) in a natural system. J. Fish Biol. In press.

Abdul Razak, S.A. and K.T. Scribner. Ecological and Ontogenetic Components of Larval Lake Sturgeon Gut Microbiota Assembly, Successional Dynamics, and Ecological Evaluation Of Neutral Community Processes. Journal of Applied and Environmental Microbiology. In Review.

Abdul Razak, S, Griffin, M. J. Mischke, C. M., Bosworth, B. G. Waldbieser, G. C. Wise, D.J. Marsh. T. L. , Scribner, K. T.. Biotic And Abiotic Factors Influencing Channel Catfish Egg And Gut Microbiome Dynamics During Early Life Stages. Aquaculture. In Review.

Dammerman, K., J.P. Steibol, and K.T. Scribner. Effects of parentage and microhabitat variation within adult‐selected spawning sites on lake sturgeon (Acipenser fulvescens) growth during early life stages. Environmental Biology of Fishes. In review.

Dammerman, K., M. Webb, and K.T. Scribner. The influence of reproductive timing on female reproductive success and ovarian quality determined using plasma testosterone concentrations in lake sturgeon (Acipenser fulvescens). J. Fish Biology. In review.

Waraniak, Justin M., Terence Marsh, and Kim T. Scribner. 18S metabarcoding diet analysis of the predatory fish community in the Black River, Cheboygan County, MI, during and after the larval lake sturgeon drift period. Molecular Ecology. In review.

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 will be tagged annually with the cooperation of Purdy Fisheries. Since 2012, 760 sturgeon have been tagged, with 174 tagged in 2017. 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, Michigan Department of Natural Resources, 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 is being proposed as the stock for this reintroduction effort due the large size of the population, on‐going monitoring efforts, and is likely similar genetically to what was historically found in the Saginaw and Maumee Rivers (GSU 1; Welsh et al. 2010). All fall fingerling stocked will receive a PIT tag.

Project Duration: Spring 2017 ‐ Annually

Contact Information: Justin Chiotti, USFWS, Alpena FWCO (Detroit River Substation), 248‐891‐0087, [email protected]

Location: Saginaw River Watershed

Project Title: Lake Sturgeon Rehabilitation in the Saginaw River Watershed

Project Description: Beginning in 2018, the Michigan Department of Natural Resources will begin stocking fall fingerling lake sturgeon in the Saginaw River Watershed. Gametes will be collected by USFWS in southern Lake Huron and Michigan State University (MSU) in the Black River to rear 500 lake sturgeon fingerlings each at the Black River facility and Genoa National Fish Hatchery. If sufficient larval fish are collected in the Black River, these will replace the collected gametes. During each fall, between 2018 and 2043, a target of 1,000 lake sturgeon will be stocked in the Saginaw River system. A target of 125 fall fingerlings each from Black River and Genoa hatchery will be stocked into the Tittabawassee, Shiawassee, Cass, and Flint rivers. All fall fingerlings stocked will receive a PIT tag.

Objectives:

1. Through annual stocking, build a genetically diverse adult population of lake sturgeon that return to the Saginaw River system. 2. Determine if there are differences in survival and stream fidelity between Black Lake source sturgeon reared at a streamside facility (on Black River) and southern Lake Huron sturgeon reared at a “traditional” hatchery. 3. Build public support for lake sturgeon rehabilitation within the Saginaw River watershed.

Project Duration: Fall 2017 ‐ Annually

Contact Information: Dave Borgeson, MDNR, Fisheries Division, 989‐732‐3541 ext. 5070, [email protected] Jim Baker, MDNR, Fisheries Division, 989‐684‐9141, [email protected]

Location(s): Detroit‐St. Clair River System; Lake Huron; Lake Erie Project Title: Geographic organization and population structure of lake sturgeon in the Lake Huron‐to‐Lake Erie corridor as inferred from long‐term, population‐scale movement patterns.

Project Description: This study uses acoustic telemetry to describe the spatial structure of lake sturgeon populations that spawn in the St. Clair and Detroit rivers in order to provide managers with information on habitat use by different sturgeon populations as well as on population‐ scale movements and dispersal patterns at ecologically‐ relevant temporal scales. 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, Lake Huron, and Lake Erie (map to the right), are allowing scientists to track sturgeon movements between feeding, overwintering, and spawning grounds over thousands of square miles. Study results will be 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.

Results to date have shown that lake sturgeon habitat use varies by release location. Lake sturgeon released into the Detroit River (black circles, left) tended to remain in the Detroit River or move up into Lake St. Clair, whereas lake sturgeon released into the lower St. Clair River (red circles) either remained in the St. Clair River or moved down into Lake St. Clair. Lake sturgeon released into the upper St. Clair river (blue circles) spread out to occupy Lake Huron, the St. Clair River, and Lake St. Clair. Significant mixing of release groups occurs in Lake St. Clair, whereas Lake Erie is rarely used by lake sturgeon, even those released into the Detroit River. The extent and timing of movements by different release groups suggest the potential for complex metapopulation dynamics, which could impact conservation strategies. Year‐round tracking of lake sturgeon movements also has confirmed the existence of migratory and river‐resident life histories. The high incidence of river residency in Detroit‐St. Clair river lake sturgeon was a surprise.

Project Duration: 2012‐2022

Contact Information: Darryl Hondorp, USGS ‐ Great Lakes Science Center (Ann Arbor, MI), 734‐214‐7241, [email protected]

Location: Garden River/St Mary’s River

Project Title: Investigation of Lake Sturgeon Spawning Migration and Larval Drift Dynamics in the Garden River

Project Description: The use of the Garden River as a spawning tributary for lake sturgeon in the St Mary’s River system is being studied. Adult lake sturgeon were captured in the lower reaches of the Garden River in short‐set gill nets in spring 2016 and 2017 targeting sturgeon migrating up the river to spawn. These sturgeon were implanted with acoustic telemetry transmitter tags and their movements are being monitored by receivers deployed in the Garden River, St Mary’s River and Lake George. In total, 39 adult lake sturgeon have been tagged. Receivers in the Garden River have recorded 2 sturgeon migrating up river to suspected spawning locations, one in spring 2016 and in spring 2017. To gain insight into the over‐ wintering movement of sturgeon, telemetry receivers were left in the water over winter where water was sufficiently deep. These receivers will be retrieved in early spring 2018, and then re‐deployed for the final year of this study.

Following the spawn, larval lake sturgeon were captured at four locations along the Garden River using larval drift nets. A total of 85 and 243 larval sturgeon were captured in 2016 and 2017, respectively, thus confirming that the Garden River is indeed a spawning tributary for lake sturgeon in the St. Mary’s River system.

Project Duration: Spring 2016 – Fall 2018

Contact Information: Lexi Sumner, A/OFRC, Phone: 705‐626‐3712 ext. 5, [email protected]

Location: Huron‐Erie Corridor

Project Title: Scent Enhancement and Tagging Effects in Juvenile Lake Sturgeon

Project Description: Restoration efforts are ongoing to supplement Huron‐Erie Corridor populations of the threatened Lake Sturgeon. Knowledge is currently limited on more effective supportive breeding programs for Lake Sturgeon. Our research aims to explore whether a supportive breeding program can be effective for lake sturgeon by focusing on two potential barriers to a successful program. Lake Sturgeon rely on imprinting behavior to find appropriate spawning grounds. To ensure successful restoration of captively released sturgeon, we will examine whether scent enhancement can impact imprinting behavior. Furthermore, tracking the movement patterns of these released juvenile sturgeon is critical to establish the success of the program. Knowledge is currently limited on whether acoustic telemetry tags impact juvenile sturgeon. Laboratory studies will be used to determine whether these tags effect swimming abilities and respiration of juvenile lake sturgeon. Collectively, the results of these studies will have implications for future conservation groups in rearing effective lake sturgeon populations while enhancing research in successful supportive breeding of species at risk.

Project Duration: Spring 2017 – Spring 2018

Contact Information: Trevor Pitcher, University of Windsor, 519‐817‐2232, [email protected] Marlena McCabe, University of Windsor, [email protected]

Location: Main Basin Lake Huron

Project Title: Great Lakes Acoustic Transmitter Observation System (GLATOS)

Project Description: Manually tracking tagged lake sturgeon in a system as large as Lake Huron is severely limited by financial constraints and staff resources. Using automated stationary acoustic receivers allows continuous tracking of sturgeon throughout the year with minimal staff involvement. Building upon the success of the receiver arrays set along the Huron‐Erie corridor, one array was placed in the Ontario waters of the Main Basin targeted at tracking lake sturgeon tagged in the Detroit‐St. Clair system and southern Main Basin of Lake Huron. In addition, a second array was deployed running along the boundary between Georgian Bay and the Main Basin. In 2017 alone 46 unique acoustic tags have been recorded, 38 of which are attached to sturgeon. The remaining tags belong to carp, lake trout, sea lamprey, and walleye. Preliminary movement analysis demonstrates that sturgeon tagged in the St. Clair River and southern Lake Huron rarely venture north of the southern Main Basin, although they have been recorded as far north as the Bruce Peninsula in previous years. Greater certainty regarding sturgeon movement in this area is pending additional data collection and analysis of 2018 data.

Table: Original tagged location of fish identified by the Main Basin acoustic receiver arrays.

R

Tagged R R

Basin Cr Detour

Location Clair

Detroit False Main Plum St Species Thames Total Common Carp 1 1 Grass Carp 1 1 Lake Sturgeon 4 34 38 Lake Trout 1 1 Sea Lamprey 1 1 Walleye 1 1 Unknown 3 Total 2 1 4 1 34 1 46

Project Duration: Spring 2013 – Fall 2018

Contact Information: Jeff Speers, MNRF, Upper Great Lakes Management Unit ‐ Lake Huron, 519‐371‐ 0420, [email protected]

Location: AuSable River, Oscoda, MI

Project Title: Assessment of Lake Sturgeon (Acipenser fulvescens) Spawning Habitat in the AuSable River, MI

Project Description: Historically, Lake Sturgeon spawning was documented in 33 known tributaries throughout the Lake Huron Basin. Overexploitation, pollution, and habitat degradation have decimated the species, and slow maturation rates, coupled with barriers to historic spawning grounds, have made recovery a slow process. In recent years Federal, State, and Tribal organizations throughout the Great Lakes Basin have focused their efforts on restoring Lake Sturgeon populations. Recent studies have shown seven of the tributaries currently support spawning populations; one of which is in Michigan waters. Four watersheds have been identified as potentially highly suitable for Lake Sturgeon restoration; one of which is a 20 km reach of the AuSable River, located from the mouth to the first upstream dam. The objective of this study is to quantify suitable spawning habitat using side‐scan sonar technology to inform decisions regarding potential reintroduction strategies in the AuSable River. The 20 km study reach was floated and scanned using a 1197ϲ Humminbird Side Imaging System in November 2017. Side‐scan sonar video recordings were collected in multiple longitudinal transects and georeferenced with GPS trackpoints. Utilizing a third‐party software, SonarTRX, raw images were processed into mosaics and imported into ArcGIS and dominant substrates were delineated. Preliminary results identify suitable spawning substrate in several areas in the upper half of the study area. The extent of habitat will be examined further; in 2018, water velocity and ponar grabs will be collected at three locations along 250 m transects from the dam to the river mouth. This information will be used to verify the substrate delineated from side‐scan sonar and determine if appropriate habitat conditions exist for Lake Sturgeon spawning.

Project Duration: Spring 2017 – Fall 2018 Contact Information: Serena Lake, Lake Superior State University, [email protected] Justin Chiotti, USFWS, Alpena FWCO (Detroit River Substation), 248‐891‐0087, [email protected]

Lake Huron Table 1. Observations or general status of lake sturgeon populations in the Lake Huron Basin. Table includes water bodies that historically supported or recent evidence exists lake sturgeon may be present. Population status definitions are: Extirpated or Extant; Re‐I (reintroduced) = fish stocked into a system with an extirpated population; Supp (supplementation) = fish stocked into a system with an extant population, or Unk = unknown. A “Yes” indicates regular observation or presumed annual occurrence. Occasional (Occ) observations are as noted. Successful reproduction was defined as recent capture of larval or juvenile sturgeon. Notes follow the table.

Observations: Basin/Site Population Size of Annual Juvenile Repr. Site Name Number Status Spawning Run Index (year) Success? Adults Spawning Larva Juveniles Lake Huron 1 Carp River, MI Extant Unk Yes Occ Unk Unk Unk 2 St. Marys River, MI ON Extant Unk Yes Unk Unk Yes Yes 3 Root River, ON Extirpated 4 Garden River, ON Extant Unk Yes Yes Yes Unk Yes 5 Echo River, ON Extant Unk Yes Unk Unk Occ 1.0 (2012) Unk 6 Thessalon River, ON Extant Unk Yes Unk Unk Unk 0.0 (2012) Unk 7a Mississagi River, ON Extant 150 Yes Yes Yes Yes Yes 7b Mississagi River Extant Unk Yes Yes Unk Yes Unk (upriver), ON 8 Blind River, ON Extirpated Occ 2.2 (2012) Unk 9 Serpent River, ON Extirpated Occ 5.8 (2012) Unk 10 Spanish River, ON Extant Unk Yes Yes Unk Yes 5.3 (2012) Yes 11 French River, ON Extant Unk Yes Unk Unk Occ Unk 12 Key River, ON Unk Unk Unk Unk Unk Unk 0.0 (2012) Unk 13 Magnetawan River, ON Extant Unk Occ Unk Unk Unk 0.0 (2012) Unk 14 Naiscoot River, ON Extant Unk Occ Unk Unk Unk Unk 15 Seguin River, ON Extant Unk Occ Unk Unk Unk Unk 16 Moon River, ON Extant Unk Yes Yes Yes Yes Yes 17 Go Home River, ON Extirpated 18 Severn River, ON Extant Unk Occ Unk Unk Unk Unk 19 Sturgeon River, ON Extirpated 20 Nottawasaga River, ON Extant 200 Yes Yes Unk Yes Yes 21 Manitou River, ON Unk Unk Yes Yes Unk Unk Unk

22 Sauble River, ON Unk Unk Occ Unk Unk Unk 0.0 (2012) Unk 23 Saugeen River, ON Unk Unk Occ Unk Unk Unk 0.0 (2012) Unk 24 AuSable River, ON Extirpated 0.0 (2012) 25 Blue Point, ON Unk Unk Yes Unk Unk Occ Unk 26 Musquash River, ON Unk Unk Occ Yes Unk Occ Unk 27 Saginaw River, MI Extant Unk Occ Unk Unk Unk Unk 28 Saginaw Bay, MI Extant Unk Yes Unk Unk Unk Unk 29 AuSable River, MI Extant Unk Occ Unk Unk Unk Unk 30 Thunder Bay River, MI Extirpated 31 Cheboygan River, MI Extant Unk Occ Unk Unk Unk Unk 32 Black Lake, MI Supp 200 Yes Yes Yes Yes Yes 33 Burt/Mullett Lake Supp Unk Yes Occ Yes Yes 2009‐2011 Unk (including lower Black River downstream Alverno Dam) MI 34 Rifle River, MI Extant Unk Unk Yes Unk Yes 0.0 (2013) Unk 35 Au Gres River, MI Unk Unk Unk Unk Unk Unk 36 Otsego Lake Re‐I Unk Yes No No Yes No 37 Kawkawlin River, MI Unk Unk Unk Unk Unk Unk 38 Munuscong River, MI Unk Unk Unk Unk Unk Unk 39 Ocqueoc River, MI Unk Unk Unk Unk Unk Unk 40 Pigeon River, MI Unk Unk Unk Unk Unk Unk 41 Tittabawassee River, MI Extant Unk Occ Unk Unk Unk