A Dissertation Entitled Creating a Spatially-Explicit Habitat Suitability

A Dissertation entitled

Creating a Spatially-Explicit Habitat Suitability Index Model for Lake Sturgeon

(Acipenser fulvescens) in the Maumee River, Ohio

Jessica J. Collier

Submitted to the Graduate Faculty as partial fulfillment of the requirements for the

Doctor of Philosophy Degree in

Biology (Ecology Track)

______Jonathan M. Bossenbroek, PhD, Committee Chair

______Christine M. Mayer, PhD, Committee Member

______Todd Crail, PhD, Committee Member

______Daryl M. Moorhead, PhD, Committee Member

______Christopher S. Vandergoot, PhD, Committee Member

______Amanda Bryant-Friedrich, PhD, Dean College of Graduate Studies

The University of Toledo, May 2018

This document is copyrighted material. Under copyright law, no parts of this document may be reproduced without the expressed permission of the author. An Abstract of

Creating a Spatially-Explicit Habitat Suitability Index Model for Multiple Life Stages of Lake Sturgeon (Acipenser fulvescens) in the Maumee River, Ohio

Jessica J. Collier

Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Doctor of Philosophy Degree in Biology (Ecology Track)

The University of Toledo

May 2018

Biodiversity and ecological function are increasingly threatened by human impacts including fragmented systems, modified water and sediment flow, pollution, habitat degradation and alteration, overexploitation of species, and invasive species introduction. These impacts necessitate the need for conservation and restoration practices to protect natural resources and biodiversity. This dissertation outlines the development and implementation of habitat suitability index (HSI) models as tools to support species reintroduction efforts and monitor populations of imperiled species. Lake sturgeon (Acipenser fulvescens), a state listed species in Ohio, are a candidate for reintroduction in the Maumee River, Ohio, where they were historically abundant, but are now functionally extirpated. The goal of my dissertation was to determine if current habitat quantity and quality in the Maumee River are sufficient to support lake sturgeon reintroduction using habitat suitability index models for two important life stages: spawning adult and age-0 fish. The models I developed, using substrate, water velocity, and water depth, indicated that habitat quality, quantity, and connectivity for both spawning adult and age-0 lake sturgeon would support efforts to reintroduce this species. iii

The results of these HSI models were used in the development of a reintroduction plan to summarize important elements for successful reintroduction efforts. The reintroduction plan provided a comprehensive outline incorporating biological, managerial, and societal perspectives, to identify potential barriers to lake sturgeon reintroduction and highlight direct actions to increase success. HSI models are valuable tools for reinforcing species restoration plans and improve conservation monitoring. After the development of the lake sturgeon HSI models for the Maumee River, I wanted to further investigate if the model structure and habitat data could be utilized for other species in the Maumee River. I tested model transferability on native unionid communities, a highly imperiled group of organisms, and found that the HSI model structure successfully predicted higher unionid abundances in habitats designated as high-quality, compared to marginal and unsuitable habitats. The models developed in this dissertation provide a tool for resource managers to evaluate restoration practices and monitor species populations which will help protect biodiversity and sustain our natural resources.

This dissertation is dedicated to the amazing women in my life. Especially my mother,

Dalyce, and my Aunt Chris. Your steadfast encouragement, support, reassurance, and love kept me going and made this dissertation a reality. I am so grateful to you. And to my husband, Chris, who brought me dinner on many late nights, listened to countless presentations, and wholly embraced my love for sturgeon. Thank you. I love you.

Acknowledgements

The completion of this dissertation would not have been possible without support and help from the wonderful people in my life. First and foremost, I would like to thank my advisor, Dr. Jonathan Bossenbroek, for his encouragement, advice, and patience. He let me forge my own path while providing guidance and structure to keep me on track. A sincere thank you to my committee, Drs. Christine Mayer, Daryl Moorhead, Todd Crail, and Christopher Vandergoot, for their helpful insights and thoughtful challenges. I am deeply appreciative of Justin Chiotii and James Boase for their collaboration, support, and perspectives throughout this project. I would also like to express my gratitude and appreciation to the DES administrative assistants, Scott McBride & Dianne Mauter, who answered endless questions and were always quick to provide help. Further, I am so grateful to the many volunteers who provided field assistance and I owe a great deal of appreciation to my lab mates and friends who kept me going and shared endless laughs.

A special thank you to Sara Guiher, Jake Kvistad, Deepesh Bista, and Kristen Hebebrand.

To my husband, Chris, who was so steadfast in his encouragement, love, and patience – thank you for being there for me. Finally, thank you to my wonderful family, for always supporting and believing in me. To my grandparents, my Aunts & Uncles, and Steve – I owe you so much. Thank you to my mom, Dalyce, and my Aunt Chris, who have been my biggest supporters and taught me to believe in myself.

Table of Contents

Abstract ...... iii

Acknowledgements ...... vi

Table of Contents ...... vii

List of Tables ...... xi

List of Figures ...... xii

List of Abbreviations ...... xiv

List of Symbols ...... xv

1 Introduction ...... 1

1.1 Goals & Objectives ...... 7

2 Assessing the Reintroduction of Lake Sturgeon (Acipenser fulvescens) to the

Maumee River, Ohio using Habitat Suitability Index Models ...... 9

2.1 Abstract ...... 9

2.2 Introduction ...... 10

2.3 Methods...... 13

2.3.1 Site Description ...... 13

2.3.2 Field Data Collection ...... 14

2.3.3 Model Development ...... 16

2.3.4 Sensitivity Analysis ...... 18

2.3.5 Habitat Connectivity ...... 19 vii

2.4 Results ...... 19

2.4.1 Spawning Adult HSI Model ...... 19

2.4.2 Age-0 HSI Model ...... 20

2.4.3 Sensitivity Analysis ...... 21

2.4.4 Habitat Connectivity ...... 23

2.4.5 Relatedness of Habitat Variables ...... 23

2.5 Discussion ...... 24

2.5.1 Implications for Reintroduction ...... 29

2.6 Acknowledgements ...... 31

3 Maumee River Lake Sturgeon Reintroduction Plan ...... 46

3.1 Executive Summary ...... 46

3.2 Introduction ...... 49

3.2.1 Biology and Historic Status of Lake Sturgeon in the Maumee

River ...... 52

3.2.2 Assessing Lake Sturgeon Habitat in the Maumee River ...... 54

3.2.2.1 Objective 1 ...... 54

3.2.3 Potential Habitat Constraints ...... 56

3.3 Lake Sturgeon Reintroduction Strategy ...... 60

3.3.1 Objective 2 ...... 60

3.2.2 Biological Monitoring ...... 65

3.2.2.1 Objective 3 ...... 65

3.2.2.2 Objective 4 ...... 66

3.2.2.3 Objective 5 ...... 67

viii

3.3.3 Public Education and Outreach ...... 68

3.3.3.1 Objective 6 ...... 68

3.3.4 Regulation and Enforcement Strategies ...... 70

3.4 Long-Term Management and Future Goals ...... 71

3.5 Acknowledgments...... 72

4 Using a Habitat Suitability Index Model to Locate Unionid Communities in Large

Rivers: A Case Study from the Maumee River, USA ...... 83

4.1 Abstract ...... 83

4.2 Introduction ...... 84

4.3 Methods...... 87

4.3.1 Study Area Description ...... 87

4.3.2 Model Development ...... 88

4.3.3 Model Testing and Unionid Community Assessment ...... 90

4.4 Results ...... 91

4.4.1 Habitat Delineations ...... 91

4.4.2 Unionid Community Assemblage ...... 92

4.4.3 Model Assessment ...... 93

4.5 Discussion ...... 93

4.5.1 Unionid Community Assemblages ...... 94

4.5.2 Modelling Directions ...... 95

4.5.3 Management and Ecological Implications ...... 96

4.6 Acknowledgments ...... 97

5 Dissertation Conclusion ...... 106

5.1 Practical Guidelines and Recommendations ...... 109

5.2 Future Work ...... 110

References ...... 113

A Input Values for Lake Sturgeon Habitat Suitability ...... 133

B Potential Release Sites in the Maumee River for Age-0 Hatchery-Reared Lake

Sturgeon ...... 138

List of Tables

2.1 Age-0 lake sturgeon sensitivity analysis ...... 32

2.2 Adult lake sturgeon sensitivity analysis ...... 33

2.3 Correlation coefficients of suitability indices ...... 34

3.1 Age-0 lake sturgeon sensitivity analysis ...... 74

4.1 Unionid suitability input values ...... 98

4.2 List of unionid species surveyed ...... 99

4.3 Overview of sampling locations ...... 100

4.4 Overview of unionid survey data ...... 101

4.5 Poisson Regression analysis ...... 102

List of Figures

2-1 Study site Map ...... 35

2-2 Adult lake sturgeon suitability indices by habitat characteristics ...... 36

2-3 Age-0 lake sturgeon suitability indices by habitat characteristics ...... 37

2-4 Adult lake sturgeon habitat suitability histogram ...... 38

2-5 Adult lake sturgeon habitat suitability index map ...... 39

2-6 Age-0 lake sturgeon habitat suitability histogram ...... 40

2-7 Age-0 lake sturgeon habitat suitability index map iteration 1 ...... 41

2-8 Age-0 lake sturgeon habitat suitability index map iteration 2 ...... 42

2-9 Adult lake sturgeon indices comparisons ...... 43

2-10 Age-0 lake sturgeon indices comparisons...... 44

3-1 Map of historical sturgeon spawning stocks in Lake Erie ...... 75

3-2 Study site map ...... 76

3-3 Habitat suitability index model structure ...... 77

3-4 Map of adult lake sturgeon habitat suitability ...... 78

3-5 Map of age-0 lake sturgeon habitat suitability iteration 1 ...... 79

3-6 Map of age-0 lake sturgeon habitat suitability iteration 2 ...... 80

3-7 Comparison of river water temperatures ...... 81

3-8 Streamside rearing facility location map ...... 82

4-1 Study site map ...... 103 xii

4-2 Unionid habitat suitability indices ...... 104

4-3 Map of unionid abundance and richness ...... 105

xiii

List of Abbreviations

HSI ...... Habitat suitability index LAS ...... Lake Sturgeon

xiv

List of Symbols

Id ...... Suitability index value for water depth Is ...... Suitability index value for substrate Iv ...... Suitability index value for velocity r ...... Pearson’s correlation coefficient

Chapter 1

Introduction

Freshwater ecosystems are ecological hotspots for diversity as they host approximately 10% of known species while comprising <1% of the Earth’s surface, but these systems are increasingly subjected to ever-growing human demands that threaten biodiversity (Dudgeon et al. 2006, Strayer and Dudgeon 2010). The ecological impacts associated with anthropogenic use of freshwater systems, including fragmenting rivers, modifying water and sediment flow, pollution, habitat degradation and alteration, overexploitation of species, and invasive species introduction, interfere with the balance of these systems and can cause species extirpation and extinction (Dudgeon et al. 2006,

Strayer and Dudgeon 2010, Gangloff et al. 2016). As anthropogenic pressures on freshwater ecosystems and species increase with growing populations and demands, strategies to reconcile human needs for resources with the limited capacity of our natural environments will become necessary to protect biological integrity and biodiversity.

Freshwater species in North America face a projected mean future extinction rate of 4% per decade; a rate that is comparable to that of the fauna of tropical rainforests and five times greater than the extinction rate for terrestrial species (Ricciardi and Rasmussen

1999). Globally, we are experiencing a human-induced mass extinction at an accelerated rate, threatening biodiversity at a pace unparalleled in human history and surpassing extinction rates of the past 65 million years (Ceballos et al. 2015). These stark projections indicate a growing and dire need for collaborative action to address species conservation and ecological restoration that will curb the widespread ecological impacts of human use and ameliorate biodiversity declines and species extinctions. The purpose of this project is to examine some key, physical habitat characteristics in the Maumee River and create a habitat suitability index (HSI) model to aid species management and reintroduction practices in this system.

For many species that face severe population declines, restoration efforts are necessary to help rehabilitate population numbers. Species restoration techniques range from physical efforts to replenish populations, like captive propagation, translocation, and reintroduction efforts, to projections and monitoring techniques, like population viability analysis, predictive habitat models, trend analysis, and factor resolution, that will help ensure the best probability of success (Bowles and Whelan 1996).

Reintroduction and translocation are management strategies for restoring populations of threatened species (Minckley 1995, Shute et al. 2005, George et al. 2009, Dunham et al.

2011, Fisk et al. 2014, Hayes and Banish 2017), but they often require a feasibility assessment before application in order to insure success. Habitat suitability index (HSI) models are useful tools that can help improve the success of restoration efforts by quantifying if current habitat conditions have the capacity to support species restoration or if the target habitat has been altered to the extent that species restoration is unpractical

(Service 1980, Brooks 1997). These models often build on the knowledge of life history traits for a target species and provide a numerical index value (usually 0 – 1) that represents how suitable the habitat is for supporting the target species (Service 1980).

Habitat suitability modeling has been used extensively for conservation monitoring and to reinforce species restoration plans (Daugherty et al. 2008, Daugherty et al. 2009, Cook et al. 2010, Cianfrani et al. 2013, Kimanzi et al. 2014, Knudson et al.

2015). Lake sturgeon (Acipenser fulvescens) are a candidate for reintroduction in the

Maumee River where they were historically abundant but are currently absent from the system (Kirsch 1895, Trautman 1981, Goodyear 1982, Boase 2008). In order to determine if current habitat quantity and quality are sufficient to support lake sturgeon reintroduction, a HSI model was constructed to evaluate the feasibility of lake sturgeon restoration in this system.

This research is focused on constructing a HSI model that can be used to assess the feasibility of reintroducing lake sturgeon to a system where they are extirpated and build a set of guidelines (e.g., a restoration plan) to direct these efforts. This restoration project is important for many reasons: it will help bring awareness to an imperiled species, it can be used as a guideline for re-establishing lake sturgeon populations in other rivers where they are extirpated, it can provide economic benefits for the region through sturgeon related ecotourism activities, it will highlight the ecological contributions of the Maumee River to the Great Lakes, it could potentially be transferred to other species to improve management of the system, and it is focused on reintroducing a species which has existed for over 100 million years.

Lake sturgeon were once a common species throughout the Great Lakes with a historical abundance estimated between 671,000 – 2.3 million fish (Haxton et al. 2014), but their populations have been reduced to less than 1% of their historic abundance (Tody

1974). Anthropogenic stressors have caused widespread declines in lake sturgeon populations throughout their native range and the species has become extirpated from many areas, including the Maumee River. Published accounts suggest they may have been absent from the Maumee River as early as 1885 with no documentation of spawning or recruitment in the last century (Kirsch 1895, Trautman 1981, Goodyear 1982, Boase

2008). Lake sturgeon decline began in the mid-19th century as commercial fisheries throughout the Great lakes were starting to expand throughout the basin. Initially, lake sturgeon were considered a nuisance species to commercial fishermen, and this perception led to the indiscriminate killing of sturgeon when encountered; they were often maimed and tossed back in the water to die, burned for fuel on ships, fed to hogs, thrown on shore to rot or used as fertilizer (Harkness and Dymond 1961, Scott and

Crossman 1973). The perception of lake sturgeon as a nuisance species quickly changed with the establishment of commercial fisheries in Lake Erie and the other Great Lakes around 1860 which targeted lake sturgeon for roe (eggs), meat, skin, and swim bladders

(for isinglass production (Harkness and Dymond 1961, Scott and Crossman 1973, Tody

1974). The commercial fishery harvest for lake sturgeon rose steadily, reaching a peak catch of around 2.3 million kg in 1885, before it experienced a rapid and permanent decline (Harkness and Dymond 1961, Scott and Crossman 1973). In a ten year span, the

Lake Erie sturgeon fishery fell below 453,000 kg, an 80% reduction by 1895 (Harkness

and Dymond 1961). The fishery declined to less than 2,300 kg by 1920 and all commercial fisheries in the Great Lakes were closed by the mid-1900’s (Auer 1996).

Overfishing severely depleted lake sturgeon populations but their decline was further compounded by anthropogenic stressors across the landscape. The widespread implementation of dams impeded access to spawning areas and the elimination of viable spawning habitat due to habitat degradation from deforestation, siltation, log sluicing, and pollution from manufacturing (i.e., mining and sawmills) impeded lake sturgeon spawning and recruitment around the Great Lakes (Harkness and Dymond 1961,

Trautman 1981, Auer 1996). Life history characteristics of lake sturgeon (i.e., slow age to maturity, return to natal streams for spawning, protracted spawning, etc.) also exacerbated the pressures that influenced their decline (Rochard et al. 1990, Birstein

1993, Auer 1996, Beamesderfer and Farr 1997). Today, lake sturgeon are a listed species throughout the Great Lakes basin (Haxton and Findlay 2008, Bruch et al. 2016), but restoration efforts have been initiated to restore spawning and juvenile habitats and rebuild lake sturgeon populations (Auer 1996, Schram et al. 1999, Chalupnicki et al.

2011, McDougall et al. 2014). While the specific cause of lake sturgeon extirpation from the Maumee River (i.e., overharvesting or habitat alteration) is unknown, this project will use the HSI model to assess if current habitat conditions are favorable to support lake sturgeon reintroduction.

To determine if transferability of the HSI model created for lake sturgeon to other species in the Maumee River is plausible, I tested HSI model framework could predict suitable habitat for unionids (native freshwater mussels) in the lower Maumee River.

Unionids are semi-infaunal organisms: they use a muscular organ called a foot to burrow and anchor into substrates (Bauer and Wächtler 2012). This stationary characteristic makes the adults suitable organisms to study as they are unlikely to disperse across long distances. Successfully transferring the HSI model to sport fish, invasive, rare, or cryptic species would be beneficial for monitoring and restoration work in the Maumee River and other systems. The HSI model developed for lake sturgeon will be a useful tool to guide restoration efforts in the Maumee River.

With approximately 70% of species listed as endangered, threatened, or species of concern, unionids are one of the most endangered groups of organisms in North America

(Williams et al. 1993, Master et al. 2000, Strayer et al. 2004, Watters et al. 2009). Like lake sturgeon, widespread unionid population declines have been attributed to anthropogenic influences including overharvesting, loss of habitat from channelization and dams, the introduction of invasive species, loss or decline of host fish species, and pollution (Lydeard et al. 2004, Strayer et al. 2004, Watters et al. 2009).

Unionids are found throughout the Maumee River basin (Grabarkiewicz and Crail

2006) and I evaluated if the HSI model developed for lake sturgeon could be transferred to these species by integrating habitat preferences for unionids and surveying areas delineated by the HSI model to determine presence and absence of unionid communities.

In a successfully transferred model, we would expect to find unionids present in habitats delineated as good and absent in habitats delineated as poor. The information from this

exercise will be used to evaluate the capacity of the HSI model developed for lake sturgeon to be used for evaluating habitats for other species.

1.1 Goals and Objectives

The goal of my dissertation was to create a habitat suitability index model for the

Maumee River that can be used to evaluate current habitat conditions for target species as an aid to restoration work and species monitoring in the system. The objectives of my dissertation were as follows:

1. Construct a spatially-explicit habitat suitability index model to evaluate the

quality, quantity, and connectivity of habitat in the Maumee River for lake

sturgeon. Model parameters will be designed to evaluate two life stages:

o Spawning adult lake sturgeon

o Age-0 lake sturgeon

2. Use the model framework developed for lake sturgeon to delineate habitat for

imperiled unionid communities in the Maumee River.

The HSI models assessed if conditions in the system have been altered beyond the likelihood of successful lake sturgeon reintroduction in the lower Maumee River.

Substrate composition, water depth, water velocity, water temperature, and total spawning area were analyzed to create the HSI models. A reintroduction plan for lake sturgeon in the lower Maumee River was developed to integrate results of the HSI model and provide an outline for reintroduction efforts. The plan reviewed the feasibility of 7

reintroducing lake sturgeon, based on results from the HSI model, and provided a baseline of strategies to help achieve a self-sustaining population in the system. The second objective of my dissertation was to determine the transferability of the HSI model developed for lake sturgeon by testing if it could successfully delineate habitat for imperiled unionid communities in the Maumee River. This objective was tested by field surveys to detect the presence and absence of unionid communities in areas delineated by the HSI model as good, moderate, or poor habitat.

Chapter 2

Assessing the reintroduction of Lake Sturgeon (Acipenser fulvescens) to the Maumee River, Ohio using Habitat Suitability Index Models

2.1 Abstract

Lake sturgeon (Acipenser fulvescens) are a candidate for reintroduction in the

Maumee River, Ohio, where they were historically abundant, but are now functionally extirpated. The objective of this work was to determine if current habitat quantity and quality are sufficient to support reintroduction in the lower Maumee River using a spatially explicit habitat suitability index model for two lake sturgeon life stages; spawning adult and age-0. Substrate, water depth, and water velocity were assessed and integrated into a suitability index values to delineate good, moderate, and poor areas throughout the lower Maumee for each life stage. Substrate and water depth were surveyed simultaneously using side-scan sonar and in situ validation while water velocity was modeled with HEC-RAS software and discharge data from the USGS gage on the river. Each habitat characteristic was mapped as a spatially explicit layer in ArcGIS and combined to provide an overall assessment of habitat suitability and connectivity. Model

results indicate the lower Maumee River contains 156 hectares of good habitat for spawning adults and 529 hectares of good habitat for age-0 lake sturgeon, mostly downstream of areas delineated as good spawning habitat which will provide optimal nursery areas for age-0 fish after hatching. The results of these models indicate that habitat for both spawning adult and age-0 lake sturgeon is not limiting in the Maumee

River; thereby supporting efforts to reintroduce the species to this system.

2.2 Introduction

Lake sturgeon (Acipenser fulvescens), the largest and oldest fish in the Laurentian

Great Lakes, belong to one of the most threatened vertebrate groups (order

Acipenseriformes) in the world (Birstein 1993, Pikitch et al. 2005, Ludwig 2006) and are listed as endangered, threatened, special concern, or critically imperiled in all states and provinces of the Great Lakes basin (Galarowicz 2003, Bruch et al. 2016). Although once common in the Great Lakes with a historical abundance estimated between 671,300 – 2.3 million fish (Haxton et al. 2014), lake sturgeon have been reduced to less than 1% of historic levels and extirpated in many areas due to overharvesting, habitat degradation, and blocked access to spawning habitat (Harkness and Dymond 1961, Scott and

Crossman 1973, Tody 1974, Auer 1996, Peterson et al. 2007). To mitigate and reverse these declines, management groups have focused efforts on rehabilitating lake sturgeon stocks throughout the basin.

Successful rehabilitation efforts have been implemented throughout their native range to increase numbers, rebuild habitats, and reintroduce stocks (Schram et al. 1999, 10

Auer 2003, Bezold 2007, Smith 2010, Roseman et al. 2011, Hayes and Caroffino 2012,

Dittman 2015). The Maumee River, a Lake Erie tributary that once hosted spawning lake sturgeon, is a candidate for reintroduction efforts to reestablish the fish in this system.

While habitat fragmentation and destruction are often listed as the primary driver of lake sturgeon declines, it is not currently known if lake sturgeon were extirpated from the

Maumee River because of altered habitat, blocked access due to dams, pollution, or overharvesting in Lake Erie (Harkness and Dymond 1961, Trautman 1981, Auer 1996).

This study aims to address this part of this unknown by assessing if sufficient suitable habitat for lake sturgeon exists to support species reintroduction.

Lake Erie historically had the largest stock of lake sturgeon in the Great Lakes, approximately 300,000 – 1.1 million fish (Haxton et al. 2014), with nineteen lake sturgeon spawning stocks identified (Goodyear 1982). Currently, the only existing Lake

Erie spawning stocks are in the connecting waterways; the Detroit-St. Clair river system and the Niagara River. The Maumee River stock was largely depleted by 1885 with no record of successful spawning documented in the last century (Smith and Snell 1891,

Kirsch 1895, Langlois 1954, Trautman 1981, Goodyear 1982, Boase 2008, Mapes et al.

2015). Recent surveys focused on detecting a viable population have not discovered evidence of spawning or recruitment in the Maumee River (Boase 2008, Chiotti et al.

2016b). Although some anecdotal records exist (Pollick 2001), the low frequency of sightings coupled with lack of detection indicates lake sturgeon are functionally extirpated from the Maumee River. Furthermore, lake sturgeon have a low straying rate from nearby stocks in the Detroit-St. Clair river system (Chiotti et al. 2016b), which

suggests they are not likely to reestablish on their own and will require assistance to reintroduce the extirpated Maumee River stock.

An initial step in a reintroduction effort is to determine if current habitat conditions can support the reintroduced species or if the target system has been so altered that species reintroduction is impractical without habitat restoration efforts. Habitat suitability index (HSI) models are commonly used for conservation monitoring and to support species reintroduction plans (Daugherty et al. 2008, Cook et al. 2010, Cianfrani et al. 2013, Kimanzi et al. 2014, Knudson et al. 2015). By quantifying and qualifying if habitat conditions and connectivity will support reintroduction efforts, HSI models can inform management decisions to improve reintroduction success (Service 1980, Brooks

1997). HSI models also have the capacity to identify what resources, specific to a species’ life history requirements, may be limiting within a system, thereby directing management or restoration efforts to bolster limited resources for reintroductions.

Many HSI models are constructed to assess habitat suitability for different life stages (Threader et al. 1998, Daugherty et al. 2008, Fisk et al. 2014) as some species, like lake sturgeon, utilize a variety of habitats at different times during their life history.

Stage-specific HSI models for lake sturgeon reintroduction are important as the spawning adult and age-0 life stages require differing habitats within a riverine system and the exclusion of adequate habitat for one life stage would hinder the establishment of a self- sustaining populations. Evaluating species habitat requirements through ontogenetic shifts provides a more robust habitat assessment to assess species reintroduction efforts.

In the Great Lakes, adult lake sturgeon migrate from lacustrine systems into riverine environments in early spring for spawning (Scott and Crossman 1973). This project aimed to use stage specific HSI models to determine if current habitat quantity, quality, and connectivity would support reintroduction efforts into the Maumee River.

The main goal was to answer the question, is habitat in the Maumee River suitable and sufficient to support both spawning adult and age-0 lake sturgeon? Habitat suitability index models were selected to answer this question because model inputs (i.e., habitat characteristics) can be individually adjusted to assess how each characteristic affects the final model output. The spatially-explicit design also allow for easy visualization and calculation of habitat areas to determine total optimal habitat and connectivity between patches. The results of this research will provide recommendations to guide management efforts aimed at creating a self-sustaining lake sturgeon spawning stock in the Maumee

River of 1,500 adults through 20-25 years of fingerling stocking. This study provides the framework for a broader reintroduction plan to address strategies for rearing and reintroduction and outline objectives and considerations needed for long-term management success.

2.3 Methods

2.3.1 Site Description

The Maumee River is a seventh-order stream that begins at the confluence of the

St. Marys and St. Joseph Rivers near Fort Wayne, IN and extends over 210-rkm (river kilometers) to North Maumee Bay in Lake Erie (Figure 2-1). With a watershed greater 13

than 17,000 km2, the Maumee River is the largest Great Lakes tributary (Herdendorf

1990). The study area for this project was the lower Maumee River, which encompasses approximately 56-rkm from the first geographic constraint, the low-head Grand Rapids-

Providence dams, to the river mouth at North Maumee Bay. The lower Maumee River consists of several distinct habitats: a shallow, bedrock dominated segment with intermittent rapids below the dam; a sinuous, braided stretch with scattered islands; then a wide, relatively deep (mean 9.14 m) segment comprised of a maintained shipping channel. The last 15-rkm is dredged by the U.S. Army Corps of Engineers annually, which removes approximately 229,500 tons of sediment from the river.

2.3.2 Field Data Collection

To create the spatially explicit HSI models, we collected data for substrate, water depth, and water velocity in the Lower Maumee River. Substrate and water depth were surveyed between June and September 2014 - 2016. To identify substrate types, side-scan sonar videos were collected with a Humminbird 998C Side Imaging unit (Humminbird®

Company, Eufaula, AL) and bow-mounted transducer and post-processed in SonarWiz 5

(Chesapeake Technologies 2014). We applied bottom tracking to remove the water column (i.e., reduce the empty space below the transducer that does not receive a reflected sonar pulse) measured by the transducer and automatic gain control to reduce incidence angle of the beam and clarify the images. The sonar videos were converted to image files and imported to ArcGIS 10.3 (ESRI 2011) to visually delineate substrate composition. Substrates were classified into the following categories based on grain size scales and texture used in other lake sturgeon HSI models (Threader et al. 1998,

Daugherty et al. 2009): organic, clay, silt, sand (1-2 mm), gravel (>2-80 mm), cobble

(>80-250 mm), boulder (>250 mm), or bedrock. We created a new feature dataset and used the ‘Editor’ tool in ArcGIS to digitize polygons around substrate patches and assign dominant substrate classification to each polygon.

To inform substrate delineations, we compared side-scan sonar images to data from visual assessments collected in the field (this study and Boase 2008). For this study, visual assessment data were collected in transects perpendicular to the shore every 250 m in areas of heterogeneous substrate compositions (i.e, braided river areas around island complexes which comprised sections of the river from the Grand Rapids-Providence dam to Audubon Island) and every 1.5 km in areas composed of more homogenous substrates

(i.e., straight runs and the river section between Audubon Island and the river mouth). We documented substrate classifications at three positions along each transect, on the right bank, center, and left bank. In wadable stretches (i.e., water depths less than 1.2 m), substrate was visually or tactilely assessed within a 0.5 m quadrat to estimate size and dominate substrate types. In water depths greater than 1.8 m, we collected substrate samples with an Ekman dredge. Contents of the dredge were emptied into a bin to visually estimate substrate size and classification. Dominant (primary) and sub-dominant

(secondary and tertiary) substrate classifications were recorded within each quadrat and dredge for later comparison to side-scan sonar video visual assessments. Dominant substrate classifications were ascribed to substrates comprising more than half the sample area while sub-dominant classifications were ascribed to substrates comprising less than half the sample area but more than one-sixth.

Water depths were collected with the Humminbird Side Imaging unit simultaneously as side-scan sonar video was recorded. Because water depth data were collected on multiple sampling dates and represented different discharges and water depths throughout the field season, we corrected and standardized each survey date to

June 15, 2015 using the USGS Gauge at Waterville, OH (Gauge 04193500) to make water depths comparable. Water depth was post-processed in SonarWiz 5 and imported to ArcGIS as a bathymetric file in raster format. From the raster file, we randomly extracted1000 raster values to points and interpolated with Empirical Bayesian Kriging to produce a water depth polygon layer with 10 x 10 m cells.

Two water velocity models were created with the Army Corps of Engineer’s

Hydrologic Engineering Center's River Analysis System (HEC RAS) software (Engineers

2016), one for each of the two life stages of interest. We used the average April discharge from 1930 – 2015, collected from the USGS Gauge 4193500 online database, for spawning adults and average June discharge from 1930 – 2015 for age-0 sturgeon. A triangulated irregular network (TIN) layer of the Maumee River served as a base layer and we created 122 cross-section cutlines to obtain elevation data for the channel bed and floodplains along the river. A Manning’s n coefficient of 0.015 was assigned to all cross sections to represent the roughness coefficient for open channel flow.

2.3.3 Model Development

Each habitat characteristic was represented as a spatially explicit layer in ArcGIS

10.3 and reclassified in R statistical software (R Core Team 2017) as a suitability index value ranging from 0 – 1, based on known habitat preferences from peer-reviewed

literature (Appendix A). We assigned optimal habitat characteristics values between 0.8 –

1, referred to as ‘good’ from here on, while habitat characteristics deemed marginal for each life stage were classified between 0.31 – 0.79 and designated as ‘moderate’, and unsuitable habitats were assigned values between 0 – 0.3 and called ‘poor’ (Figures 2-2 and 2-3). Habitat suitability is characterized differently for spawning adult lake sturgeon than for the age-0 life stage. Spawning habitat consists of coarse substrates (i.e., gravel, cobble, and boulders) approximately 10 – 50 cm in diameter with plentiful interstitial spaces, moderate water velocity, water depths no less than 0.3 m, and adequate area for spawning (Harkness and Dymond 1961, Threader et al. 1998, Bruch and Binkowski

2002). The interstitial spaces of coarse substrates protect demersal eggs and newly hatched larvae from predation as well as allow water flow to oxygenate the eggs and keep them clean free of particulates. Water velocity typically between 0.5 – 1 m/s is optimal to oxygenate eggs and keep them free from siltation, but water velocity that is too high could crush eggs or dislodge them from the interstices (Kempinger 1988, Threader et al.

1998, Bruch and Binkowski 2002). Spawning sturgeon are typically found in depths between 0.3 – 8 m (Scott and Crossman 1973, LaHaye et al. 2003, Chiotti et al. 2008,

Shaw 2010). Adequate spawning area, defined as 13 – 48 m2 per female (Fortin et al.

2002) or a minimum patch size of 700 m2 for a spawning population (Bruch and

Binkowski 2002), is ideal to reduce crowding and optimize eggs and larval success. After hatching, the larval lake sturgeon remain in the interstices of coarse substrates until the yolk sac is absorbed (Kempinger 1988). In most systems age-0 lake sturgeon disperse to areas of fine sediments (i.e., sand, silt, and gravel) (Threader et al. 1998, Holtgren and

Auer 2004), slightly slower water velocities between 0.1 – 0.7 m/s (Auer and Baker 2002,

Benson et al. 2005, Dittman and Zollweg 2006), and similar water depths typically between 0.2 and 6 m (Kempinger 1996, Threader et al. 1998, Benson et al. 2005, Friday

2006).

We combined the suitability indices of each habitat layer using geometric means to produce an overall habitat suitability index model for the river in 10 x 10 m grid cells

(Equation 1). Geometric mean was used because the variables are not likely independent of one another and some interaction certainly occurs (Threader 1998).

Equation 1:

1/3 퐻푆퐼 = (퐼푠 × 퐼푣 × 퐼푑)

where Is represents the substrate suitability index value, Iv is the velocity suitability index value, and Id is the water depth suitability index value.

2.3.4 Sensitivity Analysis

We conducted a sensitivity analysis to estimate how each suitability index value, when individually increased and decreased by both 10% and 25%, would change the overall HSI model output for each life stage. Each habitat variable was manipulated separately to generate the total HSI model (Equation 1), resulting in 12 alternative model outputs for the spawning adult model. For the age-0 model, I conducted an additional eight model output that did not include water depth (Tables 2-1 and 2-2). Then, I evaluated how the overall designations of good, moderate, and poor habitat in the HSI

model changed as each habitat variable was increased or decreased by either 10% or

25%.

2.3.5 Habitat Connectivity

Connectivity was estimated as the linear distance of the river thalweg between the edge of good (suitability index 0.8 – 1) spawning polygons and downstream good age-0 polygons. Through this calculation, we could estimate the distance newly hatched larvae would likely drift from good HSI spawning habitat before encountering habitat identified as good for age-0 fish.

2.4 Results

2.4.1 Spawning Adult HSI Model

The spawning adult HSI model classified approximately 7.7% of the lower

Maumee, which represents 156 hectares, as good habitat while 49.1% (1002 ha) and

43.2% (881 ha) classified as moderate and poor habitat, respectively (Figure 2-4). The majority of good spawning habitat (suitability index 0.8 – 1) was identified near the

Bluegrass Island (rkm 25) and Audubon Island (rkm 22) complexes and further upstream between Van Tassel Island (rkms 45-48) and the Missionary Islands complex (rkms 35-

40) (Figure 2-5). The lower 14 rkm included the shipping channel and was comprised mostly of soft sediments, delineated as poor habitat (suitability index 0 – 0.3) for spawning lake sturgeon (Figure 2-5). The substrate layer classified as good around the island complexes throughout the system and poor in the shipping channel with the

remainder of the river identified as moderate (suitability index 0.31 – 0.79). The least restrictive habitat characteristic was water depth, as a majority of the system classified as good with only a small fraction as moderate and no areas classified as poor. The individual water velocity later contained the highest amount of poor habitat with a majority of the thalweg and upstream areas of bedrock identified as poor. A large proportion of downstream areas, which is a wider and deeper section of the river, identified as good with moderate habitats.

2.4.2 Age-0 HSI Model

The initial age-0 HSI model classified 575 hectares, or 28% of the total area, as good habitat while the remaining area (1465 ha) delineated as moderate with no classification of poor habitat (Figures 2-6 and 2-7). When reviewing the model inputs and suitability for each characteristic, we suspected water depth, which classified as good or moderate throughout the lower Maumee, was likely inflating the model results by overcompensating for poor classification of the two other variables. For instance, if a cell classified as poor velocity, poor substrate, and good water depth, the overall value of the cell based on our index values would be designated as moderate. The sensitivity analysis for age-0 habitat characteristics indicated that even when water depth suitability indices were reduced by 25% and combined with the other two habitat characteristics, the final

HSI model still did not produce any habitat delineations of poor (Table 2.1). This further suggested that because water depth was delineated as good throughout most of the river, it was likely outweighing the substrate index, which relates to food availability, and the velocity index, which relates to the ability of the fish to maintain position in the system,

both of which are likely more important for predicting habitat suitability than water depth. Based on these assumptions, we created a second, more conservative age-0 HSI model that used only substrate and water velocity to predict suitable habitat (Figure 2-8).

The second model predicted 529 ha (26%) of good habitat, similar to the first model

(Figure 2.6), and indicated 62% (1266 ha) moderate habitat (down from 72% in the initial model) and 12% (246 ha) poor habitat for age-0 lake sturgeon. Most good habitat for age-

0 lake sturgeon classified between Bluegrass Island and the Delaware and Grassy Island complex, adjacent areas identified as ideal for spawning, with some good habitat upstream around the Missionary Island complex (Figure 2-8).

The substrate layer identified good substrate throughout the Maumee River except in a 7 rkm of poor bedrock substrate. The only area depicted as moderate substrate was the shipping channel, the lower 14 rkm before the river mouth. Water depth, as previously stated, was classified as good throughout most of the system with only the shipping channel classified as moderate and no delineation of poor. Water velocity delineated as the most limiting habitat characteristic in the age-0 model and the HEC-

RAS output depicting most thalweg areas as potentially too fast flowing for age-0 sturgeon. Most areas of flow refuge, classified as good and moderate, were located around the island complexes and along river banks.

2.4.3 Sensitivity Analysis

The sensitivity analysis assessed how variations in each habitat index value would impact the overall HSI model outputs when individually increased or decreased by 10% or 25%. For the spawning adult HSI, variations in velocity had the greatest impact on the

model and when increased by 25%, resulted in a nine-fold increase in good habitat and eliminated the presence of poor habitat. In contrast, decreasing velocity had a similar effect on the model output compared to the other two variables; producing the same amount of good habitat as most other model variations when reduced by 10% but decreasing good habitat to 7.7% proportionally (Table 2.2). Variations in substrate and water depth produced similar proportions of good, moderate, and poor habitat in the overall HSI model during the sensitivity analysis. However, when water depth was decreased by 25%, it yielded a model output with more poor delineations compared to a velocity decrease of the same increment. The sensitivity analysis also illustrates the significance of substrate on the adult model. In the initial model iteration, soft substrates like silt and clay were given a suitability index value of zero as these fine-grain substrates are likely to foul eggs; making reproduction unsuccessful. During the sensitivity analysis, when these substrate indices were increased, they yielded far more moderate habitat delineations than poor.

The sensitivity analysis confirmed that water depth had a disproportionate effect on the age-0 HSI model compared to substrate and velocity indices (Table 2.1). In all scenarios including water depth, and even when the water depth suitability index was decreased by 10% and 25%, the overall HSI model did not produce any poor habitat.

When water depth was removed and the sensitivity analysis conducted with models using only substrate and velocity, the amount of good, moderate, and poor delineations fluctuated very little. Substrate and velocity had similar effects on model output, but when velocity was decreased by 25%, model output had slightly fewer good delineations

than when substrate was decreased by the same increment. Overall, I conclude from the sensitivity analysis that the habitat suitability index models for spawning adults and age-0 fish are relative insensitive to variation in index values

2.4.4 Habitat Connectivity

Connectivity between spawning areas and age-0 habitat is important for the survival of age-0 lake sturgeon. The majority of good spawning habitat is located around

Blue Grass Island and the Audubon Island complex, documented historical spawning grounds (Smith and Snell 1891). These spawning sites coincide with good age-0 habitat along the margins of the river that extends for approximately 12 rkm downstream. The furthest spawning site downstream is connected to approximately 6 rkm of good age-0 habitat. Beyond the areas designated as good age-0 habitat are areas classified as moderate, and while they may not be optimal habitats, they could still support age-0 lake sturgeon. Smaller patches of good spawning habitat exist in the upper reaches of our study area around Van Tassel island. Good age-0 habitat is adjacent to these sites and downstream around Missionary Island complex.

2.4.5. Relatedness of Habitat Variables

Although we assumed some level of relatedness among our habitat variables, and used the geometric means to combine habitat layers, we also investigated if a relationship existed among each habitat index by calculating Pearson’s Correlation coefficient (r) for each pairwise comparison (Table 2.3). For the spawning adult suitability indices, there were weak relationships between the velocity indices (Iv) or substrate indices (Is) (r = -

0.266) or between velocity and depth (Id) (r = -0.187; Figure 2.9). However, substrate and 23

depth displayed a stronger correlation (r = 0.478). We found similar results for the suitability index values of the age-0 model with no correlation between velocity and either substrate (r =0.001) or depth (-0.103), but a correlation between substrate and depth (r = 0.387) (Figure 2-10). Of course, with 204,024 total observations we would expect most of these correlations between the suitability index values to be significant, but do not believe this is important to the model results based on the individual variations from the sensitivity analysis.

2.5 Discussion

This study is the first to evaluate lake sturgeon reintroduction in Lake Erie tributaries and the habitat suitability index models developed in this paper are crucial for determining if reintroduction efforts in the Maumee River would be a good use of financial and biological resources. Our HSI models for spawning adult and age-0 lake sturgeon suggest the quality and quantity of habitat in the Maumee River is sufficient to support reintroduction efforts. Model results indicate spawning adult lake sturgeon migrating to the Maumee River will have access to 156 ha of optimum spawning habitat and juvenile fish emerging from successful spawning events will have access to 529 hectares of optimal age-0 habitat. Previous literature documented that spawning habitat in tributaries of Lake Michigan which host remnant populations of lake sturgeon ranges from 1-10% of the available habitat (Daugherty et al. 2008), and our findings of 7.7% good spawning habitat in the Maumee River are comparable to other systems hosting lake sturgeon. Furthermore, Fortin et al. (2002) suggest the average female lake sturgeon 24

requires 13 – 48 m2 of spawning area to maximize spawning success. Although lake sturgeon population recovery may be restricted if the species does not have access to its whole historic habitat (Auer 1999), the best estimates of our model suggests the 156 ha

(1.56 million m2) depicted in the spawning adult HSI model could support between

32,500 and 120,000 spawning lake sturgeon (based on 13 – 48 m2 for spawning females); well over our target population of 1,500 spawning adults.

Additionally, connectivity between good spawning habitat and good age-0 habitat plays an integral role in ensuring habitat requirements are met during ontogenetic shifts.

A large portion of good age-0 habitat, critical nursery areas for young fish, depicted in our models is located adjacent to or downstream of the good spawning sites with a large segment, ~12 rkm, downstream of historical spawning sites for lake sturgeon. These HSI models suggest the quantity and quality of lake sturgeon habitat is not limiting in the

Maumee River; thus, supporting the objectives for lake sturgeon reintroduction in the system.

Habitat suitability index models are a practical approach for assessing feasibility of species reintroductions and examining applicability and necessity of restoration efforts. Habitat degradation, especially of spawning and nursery areas, is a leading cause of lake sturgeon population decline throughout their native range (Harkness & Dymond

1961; Auer 1996; Holey et al. 2000; Peterson et al. 2007). In many instances, restoration efforts are needed to rebuild functional habitats for species reintroduction or population augmentation to be successful. Restoration of lake sturgeon spawning habitat has succeeded in many areas throughout their native range (Folz & Meyers 1985, Johnson et

al. 2006, Kerr et al. 2010, Roseman et al. 2011, Manny et al. 2015), and our models helped evaluate if similar restoration efforts would be necessary for reintroduction to succeed. The quantity of suitable spawning and age-0 habitat designated by our HSI models suggest that habitat is not limited in the Maumee River, thereby negating the need for habitat restoration in this instance of species reintroduction. These results further suggest that habitat limitation was likely not the driving cause of lake sturgeon extirpation in the Maumee River and could indicate that extirpation was largely due to overexploitation, decreased water quality or another perturbation within the system.

Commercial harvesting historically had a significant impact on lake sturgeon populations which experienced a rapid and permanent decline after a peak harvest of nearly 2.3 million kg per year in 1885 fell to less than 453,000 kg in 1895; an 80% reduction (Harkness and Dymond 1961). High fishing pressure over a relatively short time frame, combined with evidence that suitable spawning and age-0 habitat is not limiting in the Maumee River, suggests overexploitation could have been the driving cause of lake sturgeon extirpation in our study area, but it is hard to say what role pollution and decreasing water quality played.

Though pollution and reduced water quality are associated with sturgeon declines

(Harkness and Dymond 1961, Trautman 1981, Auer 1996), recent studies suggest sediment loads in the Maumee River are declining while the presence of lithophilic spawning fish is increasing; suggesting an improvement in water quality likely to benefit lake sturgeon reintroduction. Sediment concentration and loading trends have continually decreasing over a 30-year period, from 1975-2005 (Richards et al. 2008).

Concurrently, family level fish diversity and richness increased with the abundance and density of lithophilic spawning fish (e.g., Sander vitreus (walleye) and Percina caprodes

(log perch)), significantly increased (Mapes et al. 2014). Though lithophilic spawning fish, like Catostomus spp., Moxostoma spp., Percopsis spp., and Etheostoma spp., were absent from Maumee River surveys in 1976 and 1977, surveys in 2011 and 2012 documented the presence of these species (Mapes et al. 2014). The increasing diversity, abundance, and density of lithophilic spawning fish in the Maumee River is a good sign for lake sturgeon; indicating that water quality improvements will likely support reintroduction efforts.

Of the 19 historic lake sturgeon spawning stocks in Lake Erie, 15 are currently extirpated (Goodyear 1982, Haxton et al. 2014). The cause of extirpation, whether it be overexploitation or degraded habitat, should be evaluated on a system by system basis to inform how reintroduction efforts are implemented in each system. The HSI models developed for the Maumee River provides a tool to assess reintroduction potential based on habitat potential in other Lake Erie tributaries and could be used to determine the feasibility of restoration efforts.

The utility of this model for assessing and prioritizing lake sturgeon reintroduction efforts in other Great Lakes tributaries could also be extending to other species with similar habitat requirements. Walleye (Sander vitreus) require similar habitat characteristics for spawning as lake sturgeon (Lyttle 2008) and the three most important habitat variables for predicting optimal walleye spawning sites are depth, velocity, and substrate (Gillenwater et al. 2006); which were used to create the HSI

models in this paper. Similarly, other lithophilic spawners such as lake whitefish

(Coregonus clupeaformis), white sucker (Catostomus commersonii), shorthead redhorse

(Moxostoma macrolepidotum), and troutperch (Percopsis omiscomaycus) are known to utilize spawning reefs constructed to increase spawning habitat for lake sturgeon in the

Detroit River (Roseman et al. 2011). The HSI models constructed in this paper could be utilized to evaluate habitat quantity and quality for other species and evaluate the necessity for restoration efforts to restore or augment targeted fish stocks.

While developing these HSI models, we explored the use of some well-known ecological survey techniques in novel ways to assess habitat conditions for lake sturgeon.

For example, side-scan sonar is a commonly used tool for surveying riverine habitats

(Kaeser et al. 2010, Powers et al. 2015, Oliver et al. 2017; Walker & Alford 2017), but we implemented this technology to identify fine-scale substrate composition across a large distance to designate suitability indices calibrated for sturgeon reintroductions; a novel instance of combining this technology with HSI modeling. In contrast, previous sturgeon HSI models have employed wading poles and ponar grabs to collect substrate data for interpolation (Daugherty et al. 2009; Krieger et al. 2017), but the methods used for this study provide a more comprehensive coverage of data to inform the model.

Previous HSI models typically use flow meters, Acoustic Doppler Profilers, or

WHYSWESS hydraulic simulations to assess water velocity (Daugherty et al. 2009, Yi et al. 2014, Krieger et al. 2017). However, this model used the Army Corps of Engineer’s

Hydrologic Engineering Center's River Analysis System (HEC RAS) software (Engineers

2016) to create a large-scale velocity model for the lower Maumee River. This software

program, not previously used in sturgeon HSI models, allowed us to create a comprehensive velocity map for this very large area using discharge information and some adjustments to a triangulated irregular network layer. The velocity layer created by the HEC RAS software was conveniently produced without laborious or time-consuming field data collection and provides high resolution spatial extrapolation. However, it likely needs some further discharge data added to the model at a downstream location to balance the water flow along such a long river stretch. We suspect that one discharge input, from an upstream USGS gauge, is needed to be accompanied by a downstream discharge that would account for smaller tributary, surface water, or ground water

(spring) inputs. For example, the final model produced some high velocity outputs and failed to model water around some of the downstream island complexes; faults that could likely be remediated with more discharge data to inform the model.

Finally, because lake sturgeon are extirpated from the Maumee River, we could not validate our model by documenting current sturgeon habitat use within the river to compare to our suitability designations. Instead, we consider the model results to be a rough estimate of habitat suitability and quantity, which seems unlikely to limit reintroduction efforts.

2.5.1 Implications for Reintroduction

Successful species reintroduction is often contingent upon the quality and quantity of suitable habitat, especially if habitat requirements change through ontogeny. A crucial step to reintroduce a self-sustaining population is to first determine if current conditions

meet the habitat requirements for all life stages of the target species. This step will serve to rule out the possibility the target system has been altered to the extent that species reintroduction is not feasible. Because lake sturgeon have been extirpated from the

Maumee River for nearly a century, it was imperative to evaluate the current habitat in the river prior to expending resources for reintroduction.

The main goal of this project was to determine if habitat quality and quantity was present in the Maumee River to support lake sturgeon reintroduction efforts because it was unknown if extirpation and the lack of recolonization from nearby systems was driven by inadequate habitat or other variables. Before expending resources for reintroduction, we wanted to ensure habitat would support the species and allow the fish to become self-sustaining. Multiple ontogenetic habitat considerations within the river were evaluated to help ensure the species could become self-sustaining after reintroduction efforts. Our habitat suitability index models suggest habitat in the lower

Maumee River is plentiful for both spawning adult and age-0 lake sturgeon and thus reintroduction efforts are supported by the presence and quantity of promising habitats.

Optimal age-0 habitat is located downstream from good spawning sites, allowing changing habitat requirements through ontogenetic shifts to be met. These models may serve as a tool that can be applied to other Lake Erie tributaries to determine which systems have intact habitat and which ones would require restoration efforts before reintroductions could be accomplished; thereby prioritizing reintroduction efforts on a basin-wide scale. Continued management to rebuild lake sturgeon stocks throughout their native range should focus not only on areas with intact habitats, but also on the potential

for restoration of spawning or nursery grounds and protection of high-quality habitats from degradation.

2.6 Acknowledgements

I owe a great deal of gratitude to Justin Chiotti and Jim Boase with the USFWS for their insight, support, and dedication to this project. I would like to thank Ed Roseman, David

Bennion, and Bruce Manny at the U.S. Geological Survey and Kent Bekker from the

Toledo Zoo and Aquarium for their helpful insights during project development. A big thanks to field work volunteers Brian Schmidt, Chris Collier, Kristen Hebebrand, Ben

Kuhaneck, Wendy Stevens & Rachel Johnson. Additional thanks to friendly reviewers

Jake Kvistad, Austin Bartos, and Linnea Viccari. This project was funded by a grant provided from the U.S. Fish and Wildlife Service, #205150.

Table 2.1. Results from the sensitivity analysis for the Age-0 lake sturgeon HSI model when each habitat characteristic was individually increased (P) or decreased (M) by 10% or 25%. Sub represents substrate, Vel represents velocity, and the numbers indicate the amount of area (m2) or proportion of the area that changed with each model iteration. Area (m2) Proportion Model Description Good Moderate Poor Good Moderate Poor Substrate + velocity + depth 57516 146508 0 28.2 71.8 0.0 Substrate + velocity 52860 126576 24588 25.9 62.0 12.1 SubP10 + velocity + depth 57516 146508 0 28.2 71.8 0.0 SubP10 + velocity 53333 126103 24588 26.1 61.8 12.1 SubP25 + velocity + depth 67070 136954 0 32.9 67.1 0.0 SubP25 + velocity 53333 126103 24588 26.1 61.8 12.1 SubM10 + velocity + depth 53333 150691 0 26.1 73.9 0.0 SubM10 + velocity 52860 126576 24588 25.9 62.0 12.1 SubM25 + velocity + depth 52860 151124 40 25.9 74.1 0.0 SubM25 + velocity 40860 119483 43681 20.0 58.6 21.4 Substrate + VelP10 + depth 57516 146508 0 28.2 71.8 0.0 Substrate + VelP10 53333 126103 24588 26.1 61.8 12.1 Substrate + VelP25 + depth 67070 136954 0 32.9 67.1 0.0 Substrate + VelP25 53333 126103 24588 26.1 61.8 12.1 Substrate + VelM10 + depth 53333 150691 0 26.1 73.9 0.0 Substrate + VelM10 52860 126576 24588 25.9 62.0 12.1 Substrate + VelM25 + depth 52860 151164 0 25.9 74.1 0.0 Substrate + VelM25 40382 139054 24588 19.8 68.2 12.1 Substrate + Velocity + DepthP10 57516 146508 0 28.2 71.8 0.0 Substrate + Velocity + DepthP25 57516 146508 0 28.2 71.8 0.0 Substrate + Velocity + DepthM10 53333 150691 0 26.1 73.9 0.0 Substrate + Velocity + DepthM25 52860 151164 0 25.9 74.1 0.0

Tables 2.2. Results from the sensitivity analysis for the spawning adult lake sturgeon HSI model when each habitat characteristic was individually increased (P) or decreased (M) by 10% or 25%. Sub represents substrate, Vel represents velocity, and the numbers indicate the amount of area (m2) or proportion of the area that changed with each model iteration. Area (m2) Proportion Model Description Good Moderate Poor Good Moderate Poor Substrate + velocity + depth 20839 95584 87601 10.2 46.8 42.9 SubP10 + velocity + depth 20839 168395 14790 10.2 82.5 7.2 SubP25 + velocity + depth 20839 168395 14790 10.2 82.5 7.2 SubM10 + velocity + depth 20839 167867 15318 10.2 82.3 7.5 SubM25 + velocity + depth 15629 173077 15318 7.7 84.8 7.5 Substrate + VelP10 + depth 54745 134489 14790 26.8 65.9 7.2 Substrate + VelP25 + depth 189234 14790 0 92.8 7.2 0.0 Substrate + VelM10 + depth 20839 166457 16728 10.2 81.6 8.2 Substrate + VelM25 + depth 15629 170639 17756 7.7 83.6 8.7 Substrate + Velocity + DepthP10 20839 168395 14790 10.2 82.5 7.2 Substrate + Velocity + DepthP25 20839 173008 10177 10.2 84.8 5.0 Substrate + Velocity + DepthM10 20839 166457 16728 10.2 81.6 8.2 Substrate + Velocity + DepthM25 15629 167888 20507 7.7 82.3 10.1

Table 2.3. Pearson correlation coefficients for pairwise comparisons between each habitat index value where Is represents the substrate suitability index value, Iv is the velocity suitability index value, and Id is the water depth suitability index value. Spawning Adult Is Iv

Iv -0.226

Id 0.478 -0.187 Age-0 Is

Iv 0.001

Id 0.387 -0.103

Figure 2.1. Our study area, in the Lake Erie basin of the Laurentian Great Lakes, consisted of 56-rkm of the lower Maumee River from first geographical constraint, the Grand Rapids and Providence low head dams (indicated by the icon west of Grand Rapids), to the mouth of the river at North Maumee Bay, Lake Erie.

Figure 2.2. Estimated habitat suitability index values for spawning adult lake sturgeon in the Maumee River, OH for (A) substrate type (IS), (B) water velocity (IV), and (D) water depth (ID). Habitat suitability indices are ranked from 0 – 1 with 0 – 0.29 representing poor habitat, 0.3 – 0.79 representing moderate habitat, and 0.8 – 1 representing good habitat.

Figure 2.3. Estimated habitat suitability index values for age-0 lake sturgeon in the Maumee River, OH for (A) substrate type (IS), (B) water velocity (IV), and (D) water depth (ID). Habitat suitability indices are ranked from 0 – 1 with 0 – 0.29 representing poor habitat, 0.3 – 0.79 representing moderate habitat, and 0.8 – 1 representing good habitat.

Figure 2.4. Results of the adult lake sturgeon spawning habitat suitability index model for the lower Maumee River where (A) indicates the overall model output classified by frequency of poor, moderate, and good habitat classifications and (B) represents output displayed as finer scale distribution of suitability index values with solid bars representing poor habitats, diagonal patterns representing moderate habitats, unfilled bars representing good habitats.

Figure 2.5. Preliminary results for the spawning adult lake sturgeon habitat suitability model for the lower Maumee River.

Figure 2.6. Comparison of age-0 habitat suitability index model results from the first model iteration that included water depth indices but failed to produce poor habitat delineations and the second model iteration that excluded water depth and only used suitability indices for substrate and velocity. (A) represents the frequencies of overall model output classified by poor, moderate, and good habitat classifications for the first model iteration while (B) represents the same classifications for the second age-0 model. The model output is also displayed in finer increments of suitability index values for the first model (C) and the second model (D) with solid bars representing poor habitats, diagonal patterns representing moderate habitats, unfilled bars representing good habitats.

Figure 2.7. Preliminary results for the age-0 lake sturgeon habitat suitability index model in the lower Maumee River included substrate, water depth, and velocity but resulted in an initial model with only good (28%) and moderate (72%) habitat classification.

Figure 2.8. In the second age-0 HSI model iteration for age-0 lake sturgeon in the Maumee River, we used just substrate and water velocity, as water depth appeared to artificially inflate the habitat classifications and failed to identify areas likely to be classified as poor. In this model, total good habitat area changed very little with the exclusion of water depth, but moderate habitat fell from 78% to 62% and the classification of poor habitat, consisting of 12% of the total area, was now documented.

Figure 2.9. Pairwise comparisons of spawning adult lake sturgeon habitat index values where Is represents the substrate suitability index value, Iv is the velocity suitability index value, and Id is the water depth suitability index value.

Figure 2.10. Pairwise comparisons of age-0 lake sturgeon habitat index values where Is represents the substrate suitability index value, Iv is the velocity suitability index value, and Id is the water depth suitability index value.

Chapter 3

Maumee River Lake Sturgeon Reintroduction Plan

3.1 Executive Summary

This plan was developed to address strategies for rearing and reintroducing lake sturgeon to the Maumee River and outline objectives and considerations needed for long-term management success to aid establishment of a self-sustaining population.

Many lake sturgeon (Acipenser fulvescens) populations have been reduced to less than 1% of historical abundance (Tody 1974), consequently, rehabilitation and restoration efforts are being implemented throughout their native range (Hay-Chmielewski and

Whelan 1997, Schram et al. 1999, Auer 2003, Bezold 2007, Smith 2010, Roseman et al.

2011, Hayes and Caroffino 2012, Dittman et al. 2015). Nineteen spawning stocks of lake sturgeon were identified as historically occurring in Lake Erie (Goodyear 1982) however, recent surveys suggest lake sturgeon recruitment in Lake Erie is only supported by stocks in two connecting channels, the St. Clair – Detroit River System (SCDRS) and the

Niagara River. In the mid-1800’s the Maumee River hosted extensive spawning runs of lake sturgeon, but these were largely extirpated by 1885 with no record of successful 45

spawning in the system documented in the last century (Kirsch 1895, Langlois 1954,

Trautman 1981, Goodyear 1982, Boase 2008, Chiotti et al. 2016). Multiple factors may have contributed to lake sturgeon decline in the Maumee River including, but not limited to, over-fishing in Lake Erie, habitat degradation, and the construction of dams (Harkness and Dymond 1961, Scott and Crossman 1973, Trautman 1981, Auer 1996). However, recent surveys and habitat suitability index models demonstrate that quality, quantity, and connectivity of habitat for both spawning adult and age-0 lake sturgeon exists in the

Maumee River thereby supporting reintroduction efforts to restore lake sturgeon in this system.

This reintroduction plan outlines a comprehensive approach to incorporate biological, managerial, and community perspectives to help facilitate successful reintroduction efforts. To accomplish this, we integrated aspects of current habitat conditions, potential habitat constraints, juvenile rearing and stocking strategies, biological monitoring and evaluation, public education and outreach, regulation and enforcement, and incorporation of long-term management techniques to provide a comprehensive strategy to inform successful reintroduction and species restoration. This plan integrates an adaptive management approach to use post-stocking information, like survival rates and habitat use, to inform future decisions on stocking numbers and release locations. The Maumee River lake sturgeon reintroduction project is a multi-agency, international effort to provide a basis for continued research and strategies to restore lake sturgeon populations throughout Lake Erie.

The goal of this project is to successfully reintroduce lake sturgeon to the

Maumee River by establishing a self-sustaining population via stocking. We plan to complete the following objectives to meet this goal:

1. Estimate how much spawning and juvenile lake sturgeon habitat exists in the

lower Maumee River and calculate carrying capacity for the system using

field habitat measurements and life-stage specific habitat suitability index

models.

2. Annually stock 3,000 fall fingerling lake sturgeon into the Maumee River

(1,500 from stream-side rearing facility; 1,500 from Genoa National Fish

Hatchery).

3. Estimate and compare stocking-site fidelity rates (e.g., natal imprinting) of

lake sturgeon reared under streamside and traditional hatchery conditions.

4. Estimate and compare post-stocking survival (i.e., short term) and site fidelity

rates of age-0 fingerlings reared under streamside and traditional hatchery

conditions.

5. Evaluate the contribution of juvenile lake sturgeon reared in streamside and

traditional hatchery facilities to adjoining waters (i.e., Detroit River and

western basin of Lake Erie).

6. Develop education and outreach programs to engage the local community,

increase awareness and educate the public about native species restoration and

water quality issues pertaining to the Maumee River watershed.

A successfully reintroduced population will display long term persistence (i.e., a spawning population consisting of 1,500 sexually mature adults, representing at least 20 age classes) without the need for intervention, in this case, continued stocking (Seddon

1999). Furthermore, successful reintroduction in the Maumee River combined with other efforts to reestablish lake sturgeon populations in other Lake Erie tributaries could eventually down list and de-list the species under the Ohio Revised Code for Endangered

Species.

3.2 Introduction

Lake sturgeon are the largest and oldest fish in the Great Lakes and belong to one of the most threatened groups of vertebrates – order Acipenseriformes (Birstein 1993,

Pikitch et al. 2005, Ludwig 2006). Once common throughout the Great Lakes, a historical abundance for lake sturgeon is estimated between 671,000 – 2.3 million fish (Haxton et al. 2014). Anthropogenic influences have extirpated lake sturgeon from many areas throughout their native range and their populations have been reduced to less than 1% of their historic levels (Tody 1974). The widespread decline of lake sturgeon populations began in the mid-19th century through overharvesting and exploitation, habitat degradation, blocked access to spawning habitat from the implementation of dams, and reduced water quality (Harkness and Dymond 1961, Scott and Crossman 1973, Trautman

1981, Auer 1996, Peterson et al. 2007). Changing perspectives on lake sturgeon utility, first regarded as a useless nuisance then as a valued commodity, had a profound impact on reducing their populations.

Commercial fishermen initially regarded lake sturgeon as a nuisance because they often became entangled in nets, and thus were indiscriminately killed when encountered

(Harkness and Dymond 1961, Scott and Crossman 1973). Lake sturgeon became a valued commodity with the establishment of commercial fisheries in the Great Lakes around

1860. Lake Erie, which historically contained a robust population estimated between

294,000 – 1.1 million adult fish (Haxton et al. 2014) hosted the highest commercial harvest (Harkness and Dymond 1961, Scott and Crossman 1973). In Lake Erie, unregulated commercial lake sturgeon harvest peaked at 2.3 million kg in 1885 before a rapid decline reduced harvests by 80% within ten years (Harkness and Dymond 1961,

Scott and Crossman 1973). By 1920, only a fragment of the Lake Erie fishery remained with an annual harvest less than 2,300 kg and all lake sturgeon commercial fisheries in the Great Lakes closed by the mid-1900’s (Auer 1996). Despite closing the commercial fisheries, lake sturgeon populations were imperiled, and the species became extirpated from many areas where it once thrived. Of the original nineteen spawning stocks in Lake

Erie, five were located in Ohio including the Maumee, Portage, Sandusky, and Cuyahoga rivers and along the shore at Conneaut (Figure 3-1; Goodyear 1982). None of these stocks exist today and lake sturgeon are currently listed as Endangered in the state of

Ohio.

Overfishing depleted lake sturgeon populations but their decline was compounded by dams and habitat degradation. Widespread implementation of dams impeded access to spawning areas and reduced habitat availability while deforestation, siltation, log sluicing, and pollution from manufacturing degraded other areas (Harkness and Dymond

1961, Trautman 1981, Auer 1996). Life history characteristics, such as slow growth and maturation, imprinting and return to natal streams for spawning, and intermittent spawning allowed sturgeon to thrive for the last 100 million years but now exacerbate pressures influencing their decline (Rochard et al. 1990, Birstein 1993, Auer 1996,

Beamesderfer and Farr 1997). Low population numbers and regional extirpations combined with these life history characteristics suggest management intervention is needed to rehabilitate populations. The Maumee River, which once hosted a large spawning stock of lake sturgeon that is now extirpated, is a candidate for reintroduction efforts.

The Maumee River is a seventh-order stream that begins at the confluence of the

St. Marys and St. Joseph rivers near Fort Wayne, IN and travels over 210-rkm (river kilometers) through northwest Ohio to North Maumee Bay in Lake Erie. With a watershed greater than 17,000 km2, the Maumee River is one of the largest tributaries to the Great Lakes (Herdendorf 1990). A low-head dam constrains accessible habitat to the lower 56-rkm for species migrating upriver. The lower Maumee is characterized by distinct habitats: a shallow, bedrock dominated segment with scattered rapids below the dam; a sinuous, braided stretch with scattered islands; then a wide, relatively deep (mean

9.14 m) section ending in a maintained shipping channel. This lower 14-rkm segment between the I-75 bridge and the mouth of the river, is dredged annually by the Army

Corps of Engineers to remove approximately 229,500 tons (850,000 cubic yards) of sediment (Engineers 2015).

Lake sturgeon serve as an indicator of biodiversity and system health. Reintroducing extirpated populations throughout their native range is important to rebuild ecological integrity and maintain resilient ecosystems. Reintroduction efforts have proven successful in restoring lake sturgeon populations in other systems including the St. Louis,

Kalamazoo, and St. Regis rivers (Schram et al. 1999, Smith 2010, Dittman et al. 2015).

3.2.1 Biology and Historic Status of Lake Sturgeon in the Maumee River

Lake sturgeon are broadcast, lithophilic spawners that prefer gravel, cobble, or boulder substrates for spawning (Scott and Crossman 1973, Kempinger 1988, LaHaye et al. 1992, Threader et al. 1998, Manny and Kennedy 2002). Suitable spawning sites are characterized by clean, coarse substrates approximately 10 – 50 cm in diameter with plentiful interstitial spaces, moderate water velocity, adequate area for spawning, water temperatures from 9-16 °C, and water depths no less than 0.6 m (Harkness and Dymond

1961, Bruch and Binkowski 2002). Coarse substrates with interstitial spaces are necessary to protect the demersal eggs and newly hatched larvae from predation as well as allow water flow to oxygenate the eggs and keep them clean of particulates in the water column. Water velocity plays a key role and optimal velocity (typically between

0.5 – 1 m/s) keeps eggs oxygenated and clean, but water velocity that is too high could crush the eggs or dislodge them from the interstices (Kempinger 1988, Threader et al.

1998, Bruch and Binkowski 2002).

In the Maumee River, spawning lake sturgeon were documented primarily between the Missionary Islands near Waterville (between rkm 35-40) and Ewing Island

near Perrysburg (rkm 22) (Smith and Snell 1891, Kirsch 1895, Trautman 1981). Recent studies have focused on detecting spawning adults, eggs, or juveniles using an array of survey techniques including setlines, gillnets, egg mats, and acoustic receivers, but have not documented evidence of lake sturgeon spawning or recruitment in the Maumee River

(Boase 2008, Mapes et al. 2015, Chiotti et al. 2016). Recolonization of the Maumee

River by lake sturgeon from the nearby St. Clair – Detroit River System (SCDRS) has also been investigated. Since the SCDRS contains one of the largest populations of lake sturgeon in the Great Lakes with an estimated population near 30,000 individuals, it is possible that sturgeon from this population could stray into other tributaries with suitable spawning habitat, such as the Maumee River (Chiotti et al. 2012, Chiotti Personal

Communication). Between 2011 – 2016, 282 adult lake sturgeon have been tagged with acoustic transmitters in the SCDRS. None of these fish have been detected on acoustic receivers in the Maumee River, suggesting that if recolonization were to occur, the process would be slow (Chiotti et al. 2016). Sportsmen have provided anecdotal evidence of adult sturgeon occasionally being present in the Maumee River with the last documented sighting below the Grand Rapids and Providence Dams in 2000 (Pollick

2001). Low sighting frequency coupled with lack of detection through multiple survey efforts indicates lake sturgeon are functionally extirpated from the system and a remnant of the historically abundant population does not exist.

3.2.2 Assessing Lake Sturgeon Habitat in Maumee River

3.2.2.1 Objective 1: Estimate how much spawning and juvenile lake sturgeon habitat exists in the lower Maumee River and calculate carrying capacity for the system using field habitat measurements and life-stage specific habitat suitability index models.

Before establishing a reintroduction program, it is important to determine if the target system contains suitable habitat to meet life history requirements for the focal species. To address this idea, we developed a habitat suitability index (HSI) model to assess current habitat conditions for two specific lake sturgeon life stages: spawning and age-0 (defined here as sturgeon in their first year of life). Habitat characteristics, including substrate type, water velocity, and water depth, were assessed for the lower

Maumee River (Figure 3-2) and incorporated into a spatially explicit habitat suitability index model (Sherman et al., in prep).

Substrate and water depth were surveyed simultaneously using side-scan sonar and ground-truthing techniques while water velocity was modeled with HEC-RAS software and discharge data from the USGS gage at Waterville, OH. Each habitat characteristic was mapped as a spatially explicit layer in ArcGIS, assigned a suitability index value specific to each life stage, and then combined to provide an overall assessment of habitat suitability and connectivity. Habitat characteristics were delineated based on known habitat preferences from peer-reviewed literature (Appendix A) and assigned a habitat suitability index value between 0 – 1 which were classified into three categories: poor (0 – 0.3), moderate (0.3 – 0.8), or good (0.8 – 1) (Figure 3-3).

The HSI model indicated suitable habitat for both spawning adults and age-0 lake sturgeon is present in the lower Maumee River. For spawning lake sturgeon, approximately 10% of the lower Maumee, which represents 208 hectares, classified as good habitat while 47% and 43% classified as moderate and poor habitat, respectively

(Figure 3-4). Previous research has documented that spawning habitat in tributaries of

Lake Michigan which host remnant populations of lake sturgeon ranges from 1-10% of the available habitat (Daugherty et al. 2008), therefore 10 % total ‘good’ habitat in the

Maumee River compares well to other systems that have self-sustaining populations.

Furthermore, Fortin et al. (2002) suggest the average female lake sturgeon requires 13 –

48 m2 of spawning area to maximize spawning success. The HSI model depicts 208 hectares (2.08 million m2) classified as good spawning areas which would support roughly 43,000 spawning lake sturgeon. The majority of good spawning habitat was identified around the Bluegrass and Audubon Island complex (between rkm 22-25) near

Perrysburg and Maumee, and further upstream between Van Tassel Island and the

Missionary Island complex (between rkm 35-48). The lower 14 rkm of the river, which is the shipping channel and comprised mostly of soft sediments, was delineated as poor spawning habitat.

To create the age-0 HSI model, we used substrate and water velocity characteristics because water depth delineated as mostly good throughout the river for this life stage and seemed to inflate the results to produce an initial model without any areas of poor habitat (e.g., 28% good habitat and 72% moderate habitat; Figure 3-5). We conducted a sensitivity analysis to evaluate how each habitat characteristic, when

individually increased or decreased by 10% and 25%, would change the overall habitat suitability index classification. Even when the suitability index for water depth was decreased by 10 and 25%, it still did not yield an overall HSI model that included a designation of poor habitat (Table 3.1); consistent with our concern that water depth inflated the overall HSI model. Using only substrate and water velocity, the HSI model delineated a more conservative 26% of the lower Maumee (529 ha) as good habitat for age-0 lake while the remaining area was classified as moderate (62%; 1266 ha) and poor

(12%; 246 ha) habitat. The majority of good habitat for age-0 lake sturgeon was identified between Bluegrass Island and the Delaware and Grassy Island complex (rkm

16-25), immediately adjacent and downstream to areas identified as ideal for spawning, with some good habitat upstream around the Missionary Island complex (rkm 35-40)

(Figure 3-6). From this information, we created a list of potential release sites based on adjacent habitat suitability for age-0 lake sturgeon while also considering accommodations for public release ceremonies (Appendix B).

3.2.3 Potential Habitat Constraints

Water temperature preference and lethal thermal maxima for lake sturgeon are important considerations for reintroducing the species into a system they currently do not occupy. While lethal thermal maxima and water temperature preferences are not clearly known for lake sturgeon, they are considered a coolwater species which are often characterized as preferring water temperatures <25°C while temperatures near 31 – 33°C are likely lethal (Cech and Doroshov 2004, Lyons et al. 2009, Lyons and Stewart 2014)

and temperatures greater than 28°C may cause reduced growth rates (Mohseni et al.

2003). Therefore, we evaluated water temperatures in the Maumee River during the summer months (June – September) in 2015 to specifically monitor the frequency and duration of water temperatures exceeding 28°C. Onset® HOBO® Dissolved Oxygen

Data Loggers were installed at two locations in the river, an upstream site at Grave Island

(rkm 37; 41.466224, -83.748515) and a downstream site at Clark Island (rkm 16;

41.615963, -83.576876) near the proposed stream-side rearing facility. Data loggers were placed inside a protective perforated PVC pipe, anchored at the substrate with an 11.3 kg kettlebell, and programmed to measure dissolved oxygen and temperature at hourly intervals.

During the warmest part of the summer, water temperatures at both locations fluctuated between 19 – 29°C with an average of 23.8 ±2.3°C at Clark Island and 25.0

±2.2 °C at Grave Island. At Clark Island, water temperatures exceeded 28°C on three days (27, 28, 29 July), but fell below 28°C at night. Water temperatures at Grave Island exceeded 28°C on five days (27 – 30 July and 7 September), but similar to the downstream site, the temperatures decreased below 28°C at night.

Preliminary observations suggest water temperatures in the Maumee River would not increase mortality for lake sturgeon. On five occasions during the summer of 2015 water temperatures at the monitoring locations exceeded 28°C, a threshold that likely poses metabolic challenges to coolwater fish species (Mohseni et al. 2003), but did not exceed the proposed lethal threshold of 31 – 33°C. These observations were only recorded for one growing season and should include further surveys to assess inter-annual

temperature fluctuations and extremes in the system. While water temperatures in the

Maumee River do not currently preclude lake sturgeon reintroduction, warming climate regimes could decrease the amount of thermally suitable riverine habitats for lake sturgeon across their habitat range (Lyons and Stewart 2014). However, it is unknown how these changes will affect sturgeon populations as many species have shown juvenile acclimation to warming water temperatures and increased lethal thermal maxima (Chipps et al. 2008, Sardella et al. 2008, Ziegeweid et al. 2008, Deslauriers et al. 2016).

Therefore, there is a need to evaluate lethal thermal maxima and temperature acclimation specifically for lake sturgeon and to identify potential thermal refugia in target systems to add this information to the scientific literature and assess restoration implications across their range.

To further investigate potential water temperature limitations, we compared

Maumee River water temperatures to two southern rivers which have received lake sturgeon reintroductions, the Coosa River system and the French Broad River. The Coosa

River begins in northeast Georgia at the confluence of the Etowah and Oostanaula Rivers and flows 450 km to the northwestern Alabama. The French Broad River, a tributary to the Tennessee River, begins in southwest North Carolina near Rosman and flows for 350 km. Both river systems have been stocked with lake sturgeon broodstock from the Wolf

River, Wisconsin since 2002. Since these southern river systems have undergone similar reintroduction efforts compared to the planned efforts for the Maumee and the broodstock came from a northern stock of lake sturgeon genetics, we surmised if water temperature

in the Maumee River was not significantly warmer than these two systems, then water temperature would not limit lake sturgeon survival in our strategy.

A linear mixed-effects model (R Core Team 2017) was used to compare the average monthly temperatures of May – October from 2013 – 2017 for the Maumee,

Coosa, and French Broad rivers (Figure 3-7). Daily average water temperatures during this time period were collected from USGS gauging stations on each river; USGS

04193490, USGS 02397000, and USGS 03451500 for the Maumee, Coosa, and French

Broad, respectively. The model comparison demonstrates the Coosa River is significantly warmer than the Maumee River during all 6 months while the French Broad is significantly warmer during May and October and comparable to or cooler than the

Maumee River during August – September. As lake sturgeon have been successfully reintroduced in these southern systems, these comparisons support our decision that while

Maumee River water temperatures do approach critical metabolic thresholds for lake sturgeon, it will not likely inhibit reintroduction efforts.

Access to suitable sturgeon habitat in the upper reach of Maumee River is limited by the first geographic constraint, a pair of low head dams, the Grand Rapids and

Providence, located 56-rkm upstream. Exploring the potential to remove these dams, which span from each shoreline to Howard Island in the middle of the river, would increase the amount of available habitat an additional 44 rkm up to the Independence

Dam at Napoleon, Ohio. A feasibility study assessing the implications of dam removal on upstream erosion, downstream sedimentation, and changes in flood regime, determined there would be little to no detrimental impacts on these factors (Mueller 2008). While the

presence of these dams does not preclude lake sturgeon reintroduction, access to habitat upstream, either through a bypass or dam removal, could provide additional habitat to bolster reintroduction efforts and increase carry capacity in the system.

3.3 Lake Sturgeon Reintroduction Strategy

3.3.1 Objective 2: Annually stock 3,000 fall fingerling lake sturgeon into the Maumee

River (1,500 from stream-side rearing facility; 1,500 from Genoa National Fish

Hatchery).

The goal for creating a self-sustaining population is to have consistent, natural recruitment without a continued need for stocking and intervention. Within the Great

Lakes Basin, systems with large, stable sturgeon populations typically have an estimate adult population size between 1,100 – 5,200 fish (i.e., the Black Lake system, Sturgeon

River, Menominee River, and Detroit River) and up to 30,000 adults (i.e., St. Clair River/

Lake St. Clair system) (Chiotti et al. 2012, Hayes and Caroffino 2012). Several studies have focused on the number of adult fish a population should reach to reduce the risk of extinction and become self-supporting. A minimum viable population of 80 – 150 adults

(post-young-of-year, male and female) is needed to reduce inbreeding effects and decrease the risk of extinction (Schueller and Hayes 2010), but Auer (2003) suggests a population of 1,500 sexually mature adults should be the minimum target for building a self-sustaining population. The habitat suitability index model results suggest this target population is achievable in the Maumee River as good spawning comprises approximately 208 hectares (2.08 million m2) which could support roughly 43,000

spawning lake sturgeon. Lake sturgeon life history characteristics, such as slow maturation and intermittent spawning, indicate reintroduction efforts will likely require a minimum of 20 years before successful reproduction will help build the target population

(Auer 1996, Welsh et al. 2010).

Some potamodromous fish imprint to rivers, or cue to aspects (i.e., water chemistry) of systems in which they were spawned and will return to those systems to spawn. Lake sturgeon imprint on their natal streams, but in cases like the Maumee River where sturgeon are extirpated, there are simply no fish. There are two remaining populations that are supporting recruitment in Lake Erie, in the SCDRS and Niagara

River, but since lake sturgeon tend to have a low estimated natural straying rating rate

(3.5%) (Homola et al. 2010), recolonization of the Maumee River via sexually mature fish from existing populations is unlikely. Given these constraints, supplemental stocking is necessary to achieve restoration targets over a shorter time scale (Chiotti et al. 2016).

When reintroducing fish species that rely on natal homing or “imprinting” to return to a target waterbody, researchers often use stream-side rearing techniques to recreate this innate behavior. Specifically, eggs and larvae are reared in water pumped from the target system allowing cultured fish to imprint on the chemical signature of the desired water body. Since 2004, streamside rearing facilities have stocked more than

30,000 fingerling lake sturgeon into Lake Michigan tributaries (Holtgren et al. 2007; Rob

Elliot, USFWS personal communication). Assuming adequate numbers of adults exist and gamete collection will not affect recruitment and diversity in the donor population, directly collecting gametes (eggs and milt) from a donor population is stated as the most

appropriate collection method for reintroduction into extirpated waters (Welsh et al.

2010). Direct gamete collection increases the likelihood of success for streamside rearing facilities to reach target stocking numbers, compared to collecting naturally produced eggs or larvae for propagation. However, collecting naturally produced eggs or larvae for propagation has been shown to increase genetic diversity since a greater number of females and males contribute to offspring compared to direct gamete collection

(Crossman et al. 2011). In order to maximize genetic diversity, 10 female lake sturgeon will be targeted each year for gamete collection and the eggs from each female will be fertilized with milt from up to five males (Welsh et al. 2010).

The most appropriate donor population of lake sturgeon for this reintroduction effort would come from within genetic stocking unit (GSU) 1, Southern Lake Huron or

St. Clair River (Welsh et al. 2010) where sufficient numbers of donors can be collected.

The Southern Lake Huron/St. Clair River population is one of the largest in the Great

Lakes, with an estimated 30,000 lake sturgeon (Chiotti et al. 2012). The Michigan DNR

(MDNR), Ontario Ministry of Natural Resources and Forestry (OMNRF) and U.S. Fish and Wildlife Service (USFWS) annually collect lake sturgeon at this location through setline population assessments. Therefore, gametes will be collected from the St. Clair

River lake sturgeon population for rearing and release in the Maumee River.

Over the past four years (2012 – 2016) more than 10 black egg (ready to spawn) female lake sturgeon, along with adequate numbers of males, have been collected each year during the spawning season (i.e. over a three to four-week time period). Therefore, gamete collection will target 10 females crossed with five males per female each year.

Standard biological information (ex. total length, weight, etc.) and a genetic sample will be collected from each donor. Half of the fertilized eggs from each family will be transferred to the USFWS Genoa National Fish Hatchery (Genoa, WI) and half will be transferred to the Toledo Zoo Maumee River stream-side rearing facility (Toledo, OH).

Eggs will be reared at the two respective locations from spring through the fall until they are stocked as fingerlings into the Maumee River. Since it is currently not known when lake sturgeon imprint to a particular system during development (i.e., egg, yolk sac larvae, or juvenile), stocking fingerling sturgeon reared using stream side and traditional hatchery techniques will allow us to evaluate if one rearing technique is more effective.

Our goal is to release 3,000 fingerling lake sturgeon each fall into the Maumee

River, 1,500 from the streamside rearing facility at the Toledo Zoo, and 1,500 from the

USFWS Genoa National Fish Hatchery. Over the course of 25 years, we anticipate this stocking rate will result in a target adult population of 1,500 sexually mature individuals

15 – 25 years of age. While the target population (1,500 adults) is greater than other river systems currently being restored in the Lake Michigan basin (750 adults), we believe the

Maumee River can support this number of sexually mature adults on an annual basis based on the extent of good spawning habitat (208 hectares) identified in the system.

The stream-side rearing facility proposed for this plan will be the first lake sturgeon rearing facility for use on Lake Erie, and will be constructed on Toledo Zoo property adjacent to the Maumee River (Figure 3-8). The rearing facility will be a 3.1 m x

12.2 m trailer outfitted with McDonald-type fish egg incubating jars to hatch collected eggs and 10 circular (1.23 m width x 0.96 m depth) tanks to raise the larval and age-0

sturgeon for approximately six months. Starter tanks (0.33 m depth) will be nested in the circular tanks while rearing larvae. Lake sturgeon reared from individual female/males(s) pairs will be reared in separate rearing tanks so the progeny from each family can be equalized during the rearing process. Rearing procedures would be similar to other streamside rearing facilities in the Lake Michigan and Superior basins (Eggold et al.

2012, Bauman 2015). Recent studies to maximize survival and growth of hatchery reared lake sturgeon have made progress on developing standard operating procedures for these facilities. Bauman et al. (2016) suggest direct feeding strategies of three feedings per day of brine shrimp (Artemia sp.) significantly increase survival and body weight of larval sturgeon versus strategies that feed more frequently throughout the day and use fortified food. Rearing densities are also an important aspect as densities greater than 19,375/m2

(or more than 300 larvae in a 3.0 L tank) produced significantly smaller (by total length) fish than methods using less than 9,688 larvae per m2 (or 150 larvae per 3.0 L tank)

(Bauman et al. 2015). Rearing specifications, including larval density, feeding regime, and water temperature will be comparable between the Toledo Zoo stream-side rearing facility and the Genoa National Fish Hatchery.

The Genoa National Fish Hatchery has been in operation since 1932 and aims to assist research and management objectives to facilitate species protection and recovery efforts throughout the Great Lakes and upper Mississippi River basins. The facility contains 17 open air ponds, six raceways, and rears 23 species, including Higgins Eye mussel (Lampsilis higginsii), Winged Mapleleaf mussel (Quadrula fragosa), coaster brook trout (Salvelinus fontinalis), lake trout (Salvelinus namaycush), and lake sturgeon.

Over 30 to 40 million fish and mussels are reared annually and provided to support restoration programs for threatened and endangered species and for researchers to monitor water quality and toxicology.

3.3.2 Biological Monitoring

This reintroduction plan will initially stock 3,000 age-0 fingerlings (1,500 from traditional hatchery and 1,500 from stream-side hatchery) into the Maumee River. An adaptive management approach will be used to monitor and evaluate age-0 fingerlings in order to adjust stocking rates to achieve our target restoration goal of 1,500 adult lake sturgeon. The contribution of lake sturgeon stocked from the Maumee River to adjoining waters (i.e., western basin of Lake Erie and Detroit River) will also be evaluated through biological assessments conducted by project partners.

3.3.2.1 Objective 3: Estimate and compare stocking-site fidelity rates (i.e. natal imprinting) of lake sturgeon reared under streamside and traditional hatchery conditions.

For the past 10 years, the approach for lake sturgeon stocking in the Lake

Michigan and Superior basins has been through streamside rearing (Holtgren et al. 2007,

Eggold et al. 2012) to maximize imprinting and minimize the chance of outbreeding depression where genetically distinct lake sturgeon populations are in close proximity to one another. The current project will compare lake sturgeon spawning site fidelity rates between streamside reared (i.e., Maumee River/Toledo Zoo) and traditionally reared (i.e.,

Genoa National Fish Hatchery) lake sturgeon fingerlings. Equal numbers of fall fingerling lake sturgeon will be stocked and all marked with PIT tags. Based on the size of fingerling lake sturgeon stocked at rearing facilities in Lake Michigan and the water temperature in the Maumee River, it is expected that fall fingerlings will attain sizes large enough (150 mm) to be passive integrated transponder (PIT) tagged at time of release. As adults return to the Maumee River, they will be collected using setlines and/or gill nets to determine the proportion of individuals returning from streamside rearing vs. traditional rearing techniques. The Maumee River provides the perfect opportunity to assess this research question because no other remnant populations are found in the Lake Erie basin, minimizing the chance of outbreeding depression. Furthermore, if lake sturgeon straying were to occur the only populations that exist are in the SCDRS and Niagara River, which are considered the same genetic population (GSU 1; Welsh et al. 2010). While the initial results of this work will not be attained for at least ten years, this information will help guide future lake sturgeon restoration efforts throughout the Great Lakes.

3.3.2.2 Objective 4: Estimate and compare post-stocking survival (i.e., short term) and site fidelity rates of age-0 fingerlings reared under streamside and traditional hatchery conditions

Acoustic telemetry will be used to evaluate stocking site fidelity, survival, and movement patterns of age-0 fingerlings released from the streamside and traditional rearing facilities. A combination of fixed and mobile tracking methodologies will be employed. A curtain of fixed acoustic receivers will be placed along Maumee Bay and 65

additional receivers will be deployed at strategic areas throughout the river (i.e., stocking site and suspected stage-specific suitable habitats). Lake sturgeon detection data will also be obtained from the Great Lakes Acoustic Telemetry Observation System (GLATOS) receiver arrays within Lake Erie and the St. Clair – Detroit River System. Based on these detections, we will create individual fish recapture histories to estimate survival rates utilizing Cormack-Jolly-Seber survival models within Program MARK (White and

Burnham 1999) or by using other appropriate statistical methods. The estimated survival rates will be assessed to inform stocking numbers and assist adaptive management practices for this plan. For instance, if estimated survival is significantly lower than expected for multiple consecutive years (e.g., less than the 40-50% age-0 survival predicted by Crossman et al. 2009, Farrell et al. 2009, McDougal et al. 2014), then stocking rates will be evaluated and increased to compensate for these loses. Habitat use, based on detection and duration of time spent in different parts of the river, will be used to validate the age-0 HSI model and evaluate stocking locations for future year classes.

Areas where the age-0 sturgeon are detected for a large amount of time may be better release locations for future year classes, especially if the sturgeon are not detected actively using areas around the proposed release sites.

3.3.2.3 Objective 5: Evaluate the contribution of juvenile lake sturgeon reared in streamside and traditional hatchery facilities to adjoining waters (i.e., Detroit River and western basin of Lake Erie).

To assess progress toward meeting the Maumee River Lake Sturgeon Restoration

Program goal of establishing a self-sustaining population and evaluate the success of the stocking efforts, populations in the recipient (Maumee River and Maumee Bay) and adjoining waters will be sampled. Prior to release, each fingerling lake sturgeon will be tagged with a PIT tag. During population assessments conducted by project partners and commercial fisherman in the western basin of Lake Erie, lake sturgeon will be scanned for the presence of PIT tags to determine the percent contribution of catch originating from Maumee River stocking events.

3.3.3 Public Education and Outreach

3.3.3.1 Objective 6: Develop education and outreach programs to engage the local community, increase awareness and educate the public about native species restoration and water quality issues pertaining to the Maumee River watershed.

Public education and outreach to raise awareness will be a crucial aspect of this project. Successful lake sturgeon restoration projects are strongly driven by public sentiment and support, which aid in sturgeon recovery (Pollock et al. 2015). Signage displayed at public accesses along the Maumee River will increase the visibility of the reintroduction project, spread awareness of the history of lake sturgeon in the region, and create opportunities to engage the public in activities focused on sturgeon life history characteristics, water quality in the Maumee River, and the health of Great Lakes ecosystems. A variety of target interest groups exist for outreach and education endeavors

including sportsmen and outdoor retailers, public agencies and naturalists, non- governmental and governmental agencies, children’s groups, and media forums. There are also opportunities for developing local sturgeon awareness and conservation groups, like establishing local chapters of Sturgeon for Tomorrow and Sturgeon Conservation

Societies.

Public agencies and naturalist groups have the capacity to establish public programs, build interactive exhibits, engage members through service opportunities and are likely to reach a high volume of people. There is a broad variety of public agencies and naturalist groups in Northwest Ohio that would be ideal for broadening the reach of lake sturgeon education including the Toledo Metroparks, the Toledo Zoo, Lake Erie

Waterkeepers, Clean Streams Ohio, Scenic Rivers, city and county parks, the Black

Swamp Conservancy, Partners for Clean Streams, the Green Ribbon Initiative, and many more. Outreach and engagement through local, state, and federal agencies would also provide opportunities to reach large audiences through respected groups adept at public outreach and communication.

Sportsmen, outdoor retailers, and commercial fisheries often provide an economic incentive for maintaining and regulating fish populations. Sportsmen will be in contact with the fish (either directly or indirectly) and it is important to educate them on the necessity for protective regulations and to have them supporting restoration efforts and protective guidelines. For sportsmen and commercial or charter fisheries that may incidentally capture lake sturgeon, it is important to educate them on the identification and protection status of lake sturgeon and emphasize the use of techniques to reduce

stress and ensure survival of captured fish. In the Maumee River and Western basin of

Lake Erie, examples of target sportsmen and outdoor retailers include charter boat captains (i.e., Lake Erie Charter Captain Association), Maumee Tackle, Bass Pro Shop,

Cabela’s, fishing license counters, and homepages for fishing report websites.

As the next generation of our culture, children have the potential to drive public perceptions in the future and have the opportunity influence the perspectives of their family and community. With the Maumee River Lake Sturgeon Reintroduction Program comes the unique opportunity to develop curriculums for schools and education groups to positively engage children with lake sturgeon. Successfully reaching this target group will involve creating resource guides for teachers, establishing curriculums for school systems, park districts, and clubs, and integrating field trips to the stream-side hatchery and rearing facility at the Toledo Zoo. Aside from connecting with children directly through school programs, other target groups include clubs and groups like the Boy

Scouts and Girl Scouts of America, children-focused activities through the Toledo

Metroparks, 4-H groups, and the Imagination Station.

3.3.4 Regulation and Enforcement Strategies

Educating the public about an endangered species being reintroduced to a region is imperative, but there will also be a need to establish regulation and enforcement to protect the species as the population increases. Adult lake sturgeon will be the most conspicuous and likely life stage encountered, but it is vital to protect all life stages and identify potential threats that may counter reintroduction efforts. These threats may

include commercial fishery or recreational fishery by-catch, boating collisions during spawning runs, habitat degradation, invasive species, and treatment for sea lamprey control. While the Maumee River is currently not treated for sea lamprey (Petromyzon marinus), precaution should be taken if treatment is established in the future.

3.4 Long-Term Management and Future Goals

Reintroduction efforts in the Maumee River and other systems will require local and state-wide long-term management plans to ensure that populations are continuously monitored and managed and the reintroduction plan adapts with progress of management efforts. One obstacle consistently faced by lake sturgeon restoration projects is the lack of information regarding the age-0 life stage, including habitat use, movement, duration of stay in natal streams, survival to the next life stage, and habitat tolerances. To further improve sturgeon restoration and reintroduction plans, and subsequently improve long- term management, more research regarding this life stage is needed (Pollock et al. 2015).

Lake sturgeon life history traits, such as habitat use, diet, residence time, and spawning site selection, are often plastic, meaning they can vary significantly between different populations and systems. As this plan is focused on reintroducing an extirpated species, there is no direct way to a priori validate the habitat suitability index model or the habitat characteristic delineations. Continual research will be needed to understand more about topics such as: population dynamics, age at maturity, residence time, year- class strength, habitat use, survival, and site fidelity within the Maumee River to further evaluate the reintroduction efforts. 70

For this lake sturgeon reintroduction plan to be successful, there will need to be cohesive collaboration among interested parties to ensure education programs, continual monitoring, and protection and regulation efforts are in place for several decades. The adaptive management structure of this plan will help ensure stocking numbers and release locations reflect the survival rates and habitat use of stocked sturgeon, thereby providing the best reintroduction approach we can apply. The implementation of this plan and successful reintroduction of lake sturgeon into the Maumee River will provide a template to guide restoration projects in other Lake Erie tributaries (i.e., Portage, Sandusky,

Cuyahoga, and Conneaut rivers; Figure 3-1). In a broad context, this reintroduction plan can set in motion a strategy for lake-wide lake sturgeon population rehabilitation, creation of another meta-population, and delisting this species from the Ohio Revised

Code for Endangered Species, all of which would indicate progress and success.

3.4 Acknowledgements

A very special thank you and a great deal of gratitude go to Justin Chiotti and Jim Boase with the USFWS for their insight, support, and dedication to this project. Thank you to

Ed Roseman, Bruce Manny, & Dave Bennion (U.S. Geological Survey), Doug Aloisi

(U.S. Fish & Wildlife Service, Genoa National Fish Hatchery), and Kent Bekker (the

Toledo Zoo & Aquarium) for providing technical knowledge, perspective, and support.

Additional thanks to friendly reviewer Daryl Moorhead. A special thanks to those that helped with field work: Brian Schmidt, Chris Collier, Kristen Hebebrand, Ben Kuhaneck,

Wendy Stevens, and Rachel Johnson. This project was funded by a grant provided from the U.S. Fish and Wildlife Service, #205150.

Table 3.1: Results from the sensitivity analysis for the Age-0 lake sturgeon HSI model when each habitat characteristic was individually increased (P) or decreased (M) by 10% or 25%. Sub represents substrate, Vel represents velocity, and the numbers indicate the amount of area (m2) or proportion of the area that changed with each model iteration. Area (m2) Proportion Model Description Good Moderate Poor Good Moderate Poor Substrate + velocity + depth 57516 146508 0 28.2 71.8 0.0 Substrate + velocity 52860 126576 24588 25.9 62.0 12.1 SubP10 + velocity + depth 57516 146508 0 28.2 71.8 0.0 SubP10 + velocity 53333 126103 24588 26.1 61.8 12.1 SubP25 + velocity + depth 67070 136954 0 32.9 67.1 0.0 SubP25 + velocity 53333 126103 24588 26.1 61.8 12.1 SubM10 + velocity + depth 53333 150691 0 26.1 73.9 0.0 SubM10 + velocity 52860 126576 24588 25.9 62.0 12.1 SubM25 + velocity + depth 52860 151124 40 25.9 74.1 0.0 SubM25 + velocity 40860 119483 43681 20.0 58.6 21.4 Substrate + VelP10 + depth 57516 146508 0 28.2 71.8 0.0 Substrate + VelP10 53333 126103 24588 26.1 61.8 12.1 Substrate + VelP25 + depth 67070 136954 0 32.9 67.1 0.0 Substrate + VelP25 53333 126103 24588 26.1 61.8 12.1 Substrate + VelM10 + depth 53333 150691 0 26.1 73.9 0.0 Substrate + VelM10 52860 126576 24588 25.9 62.0 12.1 Substrate + VelM25 + depth 52860 151164 0 25.9 74.1 0.0 Substrate + VelM25 40382 139054 24588 19.8 68.2 12.1 Substrate + Velocity + DepthP10 57516 146508 0 28.2 71.8 0.0 Substrate + Velocity + DepthP25 57516 146508 0 28.2 71.8 0.0 Substrate + Velocity + DepthM10 53333 150691 0 26.1 73.9 0.0 Substrate + Velocity + DepthM25 52860 151164 0 25.9 74.1 0.0

Figure 3-1. Map of historic lake sturgeon spawning sites in the Lake Erie basin based on data from Goodyear 1982. The fish icons indicate the historic spawning sites and the corresponding numbers represent the following site names: 1. St. Clair River; 2. Lake St. Clair; 3. Detroit River; 4. Huron River; 5. Stony Point; 6. Maumee River; 7. Portage River; 8. Sandusky River; 9. Pelee Island; 10. Point Pelee shoals; 11. Rondeau Harbor; 12. Cuyahoga River; 13. Clear Creek; 14. Long Point Bay; 15. Conneaut (nearshore); 16. Walnut Creek; 17. Cattaraugus Creek; 18. Upper Niagara River; 19. Eastern basin.

Figure 3-2. Our study area consisted of 56-rkm of the lower Maumee River from first geographical constraint, the Grand Rapids and Providence low head dams (indicated by the icon west of Grand Rapids), to the mouth of the river at North Maumee Bay, Lake Erie.

Figure 3-3. Habitat Suitability Index Model structure and habitat characteristic classifications for spawning adults and age-0 lake sturgeon. Green boxes and lines indicate habitat characteristics that fall within a good or optimal range, yellow lines and boxes represent characteristics that are moderate, and red lines and boxes designate characteristics within a range that indicates poor habitat.

Figure 3-4. Preliminary results for the spawning adult lake sturgeon habitat suitability index model for the lower Maumee River. Approximately 10% classified as good habitat while 47% and 43% classified as moderate and poor habitat, respectively.

Figure 3-5. Preliminary results for the age-0 lake sturgeon habitat suitability index model in the lower Maumee River included substrate, water depth, and velocity resulted in an initial model with only good (28%) and moderate (72%) habitat classification.

Figure 3-6. In the second model iteration for age-0 lake sturgeon in the Maumee River using only substrate and water velocity, total good habitat area was 26%, moderate habitat fell was 62% and poor habitat consisted of 12% of the total area.

Figure 3-7. Comparison of average monthly river temperatures between the Coosa, French Broad, and Maumee rivers. During the summer months, water temperature in the Maumee River is comparable to the other two systems.

Figure 3-8. Location of streamside rearing facility along the Maumee River and proximity to Toledo Zoo.

Chapter 4

Using a Habitat Suitability Index Model to Locate Unionid Communities in Large Rivers: A Case Study from the Maumee River, USA

4.1 Abstract

A Habitat Suitability Index model was created to predict presence and absence of freshwater mussel (unionid) communities in the lower Maumee River. Substrate, water depth, and water velocity were assessed and translated into suitability index values to delineate good, moderate, and poor habitat classes. Substrate and water depth were surveyed using side-scan sonar while water velocity was modeled with HEC-RAS software. Each habitat characteristic was mapped as a spatially explicit layer in ArcGIS and then combined to provide an overall assessment of habitat suitability. Field surveys were conducted at 34 sites to evaluate how the model performed in predicting the presence and absence of unionid communities. Unionids were documented at 17 of the 34 sites for a total of 245 individuals comprising 10 species. A Poisson regression

(generalized linear model) indicated the HSI model predicted a higher abundance of unionids in habitats delineated as high-quality (p<0.001) than areas delineated as

marginal (p = 0.48), which in turn contained a higher abundance than unsuitable delineations (p<0.001). Nonetheless, the HSI model failed to predict a relationship between habitat delineations and species richness (all p-values >0.05). The HSI model developed in this study provides a conservation tool for managers to monitor imperiled unionid communities and to identify starting locations for unionid surveys in systems without prior survey histories.

4.2 Introduction

Unionids (freshwater mussels) are a highly imperiled group of invertebrates that play critical roles in freshwater ecosystems. As infaunal organisms, provide a plethora of benefits including bioturbation (sediment mixing), benthification of resources from the water column to substrates, nutrient cycling, sediment stabilization, and ecosystem engineering; they can also represent a large portion of biomass in some systems where they are an important food source for fishes, birds, and mammals (Vaughn and

Hakenkamp 2001, Gutierrez et al. 2003, Vaughn et al. 2004, Lopes-Lima et al. 2014,

Chowdhury et al. 2016). Life history traits such as long-life spans, relatively stationary adult stages, and sensitivity to water quality enable unionids to act as a bellwether of ecosystem imbalance or stress (Naimo 1995, Bauer and Wächtler 2012). As essential organisms in many freshwater systems, unionids are linked to the integrity of the ecosystems they occupy, but most populations are imperiled or on the brink of extinction and their population declines have been associated with impaired ecosystem function

(Haag and Williams 2014, Quinlan et al. 2015). As one of the most imperiled groups

organisms in North America (Williams et al. 1993, Stein et al. 2000), it is imperative to develop tools that can model patchiness and refine the technique of locating unionid assemblages. The aim of this research was to determine if a habitat suitability index model, created to reintroduce an extirpated fish, could also be applied to detect unionid communities thereby providing a tool for managers to assess these imperiled organisms.

Unionids are one of the most endangered groups of organisms in North America with approximately 65% of species listed as endangered, threatened, or vulnerable (Haag and Williams 2014). Their widespread population declines have been attributed to anthropogenic stressors including overharvesting, hydrologic diversions, dam implementation, habitat alteration, loss or decline of host fish, introduction of invasive species, and pollution (Lydeard et al. 2004, Strayer et al. 2004, Lucy et al. 2014).

Detailed conservation strategies have been outlined to guide protection and rehabilitation of unionid communities (NNMCC 1997).

The imperiled status and rapid decline of unionid populations underscores the need for conservation efforts to protect assemblages and their habitats. Translocation of adult mussels and release of juveniles reared in captive propagation programs have shown some success in maintaining and augmenting unionid populations (Carey et al.

2015), but many conservation challenges still impede recovery efforts. In particular, unionid conservation programs are hindered by a lack of information regarding habitat requirements that underlie unionid presence, the association between unionid communities and hydrogeomorphology, and a holistic approach to managing host fish species, abiotic conditions, and unionid assemblages (Hegeman et al. 2014, Quinlan et al.

2015, Inoue et al. 2017, Lopes-Lima et al. 2017). In addition to these conservation challenges, population monitoring can be difficult and it is essential to identify areas of unionid presence and absence in order to take stock of current population dynamics, evaluate changes in unionid assemblages, and develop management protocols to mitigate their population declines.

Unionids are relatively stationary as adults, and often patchy in distribution

(Strayer et al. 2004, Ries et al. 2016) which can hinder population monitoring, especially in large river systems. It can be difficult to identify a starting point for unionid surveys in large systems when little or no historical community data exists. Spatially explicit habitat models that identify suitable patches could improve detection and survey efficiency of unionid communities by focusing efforts on areas identified as suitable. Models that predict patch distribution are important for prioritizing management efforts by identifying both areas likely to contain mussels and areas where large unionid assemblages may influence ecosystem function (Ries et al. 2016). Habitat suitability index (HSI) models can be used to assess the quality of habitat within a system in regard to a target species.

HSI models use preferred habitat conditions associated with life history traits of a species to create a numerical index value (usually 0 – 1) that represents the suitability a system and/or the capacity for supporting the target species (Service 1980).

Recent habitat suitability index (HSI) models for lake sturgeon (Acipenser fulvescens) were created for the lower Maumee River, OH using substrate composition, water velocity, and water depth (Collier et al. in prep). Unionid communities are tightly associated with similar abiotic habitat characteristics (Inoue et al. 2017) and I wanted to

determine if the same habitat suitability model structure used for sturgeon could be applied to unionids. The objectives of this study were to (1) use pre-existing habitat data on substrate composition, water velocity, and water depth to develop a spatially explicit habitat suitability index model to delineate high-quality, marginal, and unsuitable habitats for unionids in the lower Maumee River, and (2) conduct field surveys to test if the model could accurately predict higher unionid abundance and richness in areas delineated as high-quality and lower values in the marginal and unsuitable delineations, respectively. The ability of this HSI model to accurately predict unionid abundance and richness could provide a conservation tool to help monitor community assemblages and understand abiotic conditions impacting the presence and absence of these imperiled organisms.

4.3 Methods:

4.3.1 Study Area Description

The study area consisted of a 29-rkm section of the lower Maumee River in northwestern Ohio. The Maumee River is the largest tributary to the Great Lakes, collecting water from a 17,000 km2 watershed which spans three states (Herdendorf

1990). Our study area in the lower Maumee River was between the low-head Grand

Rapids-Providence dams and the Audubon Islands (Figure 4-1); a relatively shallow and wadable section of the river characterized by bedrock and boulder/cobble deposits below the dams followed by a sinuous, braided stretch with scattered islands.

4.3.2 Model Development

In brief, a spatially explicit habitat suitability index (HSI) model to identify potential locations of unionid communities in the lower Maumee River was developed using pre-existing habitat data for water velocity, substrate composition, and water depth

(Collier et al. in prep). These data were used to generate suitability index values based on literature references (Table 4.1; Figure 4-2). Next, each index was used to generate a habitat layer as a rater layer in ArcGIS 10.3 (ESRI 2011). Finally, habitat layers were combined to create an overall habitat suitability index value representing the lower

Maumee River.

Water velocity was estimated using the Army Corps of Engineer’s Hydrologic

Engineering Center's River Analysis System software (Engineers 2016) using average

June discharge from 1930 – 2015, accessed from the USGS Gauge 4193500 online database (Collier et al. in prep). Velocity was imported as a raster layer in ArcGIS 10.3

(ESRI 2011).

Substrate and water depth were surveyed with a Humminbird 998C Side Imaging unit (Humminbird® Company, Eufaula, AL) and bow-mounted transducer between June and September 2014 – 2016. Side-scan sonar videos were collected, post-processed in

SonarWiz 5(Chesapeake Technologies 2014) software, converted to image files, and imported to ArcGIS 10.3 to visually delineate substrate composition. Substrates were classified into the following categories: organic, clay, silt, sand (1-2 mm), gravel (>2-80 mm), cobble (>80-250 mm), boulder (>250 mm), or bedrock. The ArcGIS ‘Editor’ tool was used to digitize polygons around substrate patches and assign dominant substrate

classification throughout the river. Water depths were recorded simultaneously with the side-scan sonar video and then standardized to one sampling date (June 15, 2015) using gauge height information collected from the USGS Gauge at Waterville, OH (Gauge

04193500). Water depth was post-processed in SonarWiz 5 and imported to ArcGIS as a bathymetric file in raster format. From the raster file, we randomly selected extracted1000 raster values to points and interpolated with Empirical Bayesian Kriging to produce a water depth polygon layer with 10 x 10 m cells.

For each habitat layer, I used the ArcGIS Spatial Analyst Reclass tool to reclassify each habitat value to as a suitability index value ranging from 0 – 1 with habitat suitability delineated as high-quality (0.8 – 1), marginal (0.29 – 0.79), or unsuitable (0 –

0.3) based on known habitat preferences of unionids from peer-reviewed literature (Table

4.1; Figure 4-2). From these sources, I assumed substrate composition was the most important driver of habitat selection for unionids whereas water depth was likely the least important factor, and so I weighted each variable when I combined the them using the

Spatial Analysis Map Algebra tool (Equation 4.1).

[Equation 4.1]: Unionid HSI = ((Is*3) + (Iv*2) + Id)/6

where Is represents the substrate suitability index value, Iv is the velocity suitability index value, and Id is the water depth suitability index value, and the division by 6 provides the arithmetic mean for the overall habitat suitability index value. The resulting model

produced a map identifying areas of potential high-quality, marginal, and unsuitable habitats for unionid mussels in the lower Maumee River (Figure 4-3).

4.3.3 Model Testing & Unionid Community Assessment

A qualitative field survey method for locating unionids was used to determine if the HSI model predicted different presence and absence of unionid communities in habitats designated as high-quality or unsuitable, respectively. For unionid communities, qualitative assessments provide similar estimates of species richness, diversity, and evenness as quantitative assessments (Miller and Payne 1993, Hornbach and Deneka

1996), but are better at evaluating broad distribution patterns (Obermeyer 1998) and are often preferred over quantitative assessments as a more cost effective alternative for large rivers (Miller and Payne 1993). While qualitative assessments may be limited in detecting small mussels or buried species, these methods are better at evaluating species presence and detecting rare species (Miller and Payne 1993, Smith et al. 2001).

Field surveys were conducted between July and August, 2016. Using the a priori

HSI model habitat delineations, we randomly selected polygons (discrete patches of varying sizes) that represented four high-quality, 18 marginal, and 12 unsuitable habitat designations and documented the center point of each polygon as GPS coordinates. In the field, at each GPS coordinate, a 10 x 10 m survey area was marked using a weight and float system at each corner and the center. This survey area was comprehensively searched for unionids and at each of the five points outlining the area, substrate composition was also assessed. Tactile searches were conducted at all sites except one, a

site downstream of Otter Island at rkm 43, which was too deep to implement tactile searchers. Instead, a custom-made clam rakes (garden rakes cover with 0.5 x 0.5 cm metal mesh) was used to survey unionids. To estimate substrate composition, a large metal scoop was used to sample a portion of the substrate. These five substrate samples were place in a bucket and then taken to shore where they were sifted to metal sieves to separate size classification into <2 mm, 2 – 4 mm, 4 – 6 mm, 8 – 64 mm and > 64 mm.

Unionid surveys were conducted in overlapping transects across the entire quadrat for a minimum time search of two person-hours per hectare. In quadrats with unionid presence, surveys continued beyond the minimum time search until at least five minutes after the last unionid was found. Unionids were placed in mesh bags during the surveys and then were enumerated, identified to species, measured for shell length, and replaced as close to their original location as possible. For each quadrat, we collected information on total unionid abundance and number of species. We used a Poisson regression model

(generalized linear model) in Program R (R Core Team 2017) to assess the prediction that unionid abundance and richness varied with estimate habitat suitability (Equation 4.1).

4.4 Results

4.4.1 Habitat Delineations

High-quality, marginal, and unsuitable habitats were delineated for unionids in the lower Maumee River. Marginal habitat (suitability index of 0.31 – 0.79) comprised a majority (62.2%; 1,100 ha) of the survey area, while unsuitable habitat (SI 0 – 0.3) was

delineated as the second greatest amount of area (32.8%; 580 ha) and high-quality habitat

(SI 0.8 – 1) comprised the smallest area (5.0%; 88 ha).

4.4.2 Unionid Community Assemblage

Unionids were documented at 17 4 sampled sites with a total of 245 individuals representing 10 species (Table 4.2). Of the sites with unionid presence, abundance ranged between 1 – 52 mussels per 10 x 10 plot, species richness ranged from 1 – 8 species, and

Simpson’s Diversity was between 1.0 and 6.25 (Table 4.3; Figure 4-3). Unionid shell length ranged from 10 – 163 mm with a median shell length of 72 mm. The most abundant species was Quadrula quadrula (n = 66). Although our surveys extended from rkm 22 to rkm 50 though we did not detect unionids downstream of the Missionary Island complex (rkm 35). As an aside, these surveys documented 59 mussels less than 50 mm in shell length, a size class often overlooked in tactile surveys (Meador et al. 2011), which were comprised of five species: Lasmigonia complanata (n = 2), Leptodea fragilis (n =

2), Quadrula pustulosa (n = 3), Obliquaria reflexia (n = 21), and Truncilla truncata (n =

31).

The highest abundance of unionids (52) was found in a high-quality quadrat, but unionids were absent in the other three high-quality quadrats surveyed. In marginal habitats, unionids were present in 12 of the 18 surveyed quadrats and included the most diverse communities found. In unsuitable polygons, unionids were present in four of 12 quadrats. Three of these unsuitable quadrats contain only one or two unionids, while the fourth, site 334, hosted 8 species comprised of 18 individuals for a species richness of

5.78. Although site 334 was delineated an unsuitable unionid habitat, because of substrate estimated to be bedrock, field surveys revealed the majority (71%) of substrate was fine

(<2 mm) or small (2 – 6 mm) grain sizes.

4.4.3 Model Assessment

Of the four high-quality polygons sampled, unionids were present in one quadrat

(52 individuals) which produced an average for all high-quality polygons of 13 (S.E.

±13) unionids. Marginal habitats contained an average of 9.5 (S.E. ±3.2) unionids, while habitats delineated as unsuitable contained an average of 1.8 (S.E. ±1.5) unionids (Table

4). We expected high-quality habitat delineations to contain a higher abundance and higher species richness than marginal habitat delineations, which would have a higher abundance and species richness than unsuitable habitats. The Poisson regression

(generalized linear model) indicated the HSI model for unionids accurately predicted that high-quality habitat delineations contained a higher abundance of unionids (p<0.001) than areas delineated as marginal (p = 0.48), which in turn contained a higher abundance than unsuitable delineations (p<0.001). However, the HSI model failed to predict a relationship between habitat delineations and species richness (all p-values >0.05) (Table

4.5).

4.5 Discussion

Unionids are patchy in nature (Strayer et al. 2004, Ries et al. 2016) and identifying a starting point to assess unionid communities can be difficult, especially in 92

large systems with little data on existing assemblages. The HSI model developed in this paper aimed to explore the potential of creating a spatially explicit model to identify areas of high-quality, marginal, or unsuitable habitats for unionid communities using data for water velocity, substrate, and water depth from an earlier study of this ecosystem. While these characteristics generally have not produced accurate models for predicting unionid presence or density (Newton et al. 2008), our model successfully predicted that more unionids would be present in areas delineated as high-quality habitat compared to areas delineated as marginal or unsuitable. As one of the most imperiled faunal groups, it is critical to develop tools that can model patchiness and improve locating techniques for unionid assemblages. Improving the ability to detect unionid communities will aid conservation efforts through documentation of species presence and tracking population changes.

4.5.1 Unionid Community Assemblages

In the Maumee River drainage, there are 39 documented unionid species

(Grabarkiewicz and Crail 2006) of which we encountered 10 during our surveys in the lower section of the river (Table 2). We observed the highest abundance and diversity of unionids between river kilometers 34 – 43, suggesting that the island complexes provide the right combination of water velocity and substrate composition for unionids. While the majority of species present in this study are commonly found throughout the Maumee

River drainage and hold no conservation status, two species have state listed conservation

status; Truncilla truncata (n = 48) is listed as a Species of Concern in Ohio, while

Obliquaria reflexa (n=31) is a state Threatened Species (Ohio DNR 2017).

Although capture probabilities for small mussels can be quite low, less than 10% for shells under 50 mm (Meador et al. 2011), our survey methods detected 59 unionids with shell lengths less than 50 mm (roughly 24% of our total catch in this study). The observation of multiple small-sized unionids emphasizes the potential for our sampling methods to detect a broad array of unionid sizes and species, suggesting that our results depict a more accurate assessment of the unionid community in the lower Maumee River.

4.5.2 Modelling Directions

The unionid HSI model indicates that just 5% of the lower Maumee River classifies as high-quality habitat and based on field assessments, these sites contained a higher abundance of unionids compared to marginal or unsuitable habitats. Though these results indicate the HSI model used to locate unionid communities, the lower number of sampling sites and misclassification of suitability in some instances suggests model refinement is necessary to increase the precision of habitat mapping, especially on smaller scales. In some cases, substrate interpolation incorrectly designated substrate type which led to misidentified habitat suitability. For instance, site 334 (rkm 37) delineated as unsuitable unionid habitat, based on the substrate layer which indicated bedrock. Field surveys revealed the majority (71%) of substrate was fine (<2 mm) or small (2 – 6 mm) grain sizes; indicating high-quality unionid habitat. This site, deemed to be unsuitable by our HSI model calculations, should have been classified as high-quality habitat and upon

field assessments, we documented 18 individuals comprising 8 species and a species diversity index of 5.78

To combat errors with data interpolation, one could invest more time and effort to collect more field data that would better inform the model and interpolation. Instead, we suggest the potential to use geomorphology features of the river, such as channel gradient and sinuosity angles, to predict velocity and substrate thereby eliminating the need for time consuming field work and post processing of data. Unionid abundance is associated with geomorphology features (Gangloff and Feminella 2007), which have been used to successfully predict community presence at large scales (Brainwood et al. 2008). By employing geomorphology features, large-scale characteristics such as channel gradient, attack angle of water flow, and sinuosity could be used as proxies for water velocity and depth could then characterize substrate type. We could also suggest, when conducting surveys in deeper habitats, to combine HSI models with sampling techniques like side scan sonar, which have been successfully employed to identified mussel beds in large river systems (Powers et al. 2015).

4.5.3 Management and Ecological Implications

Spatially explicit habitat suitability index models are a useful predictive tool that can help stakeholders and managers prioritize conservation efforts. The habitat suitability index model developed in this study successfully predicted high-quality habitats that hosted the greatest average abundance of unionids. Although this model can refine search areas for unionid surveys to help locate and assess imperiled populations, improvements can be

made to increase the accuracy and precision of habitat delineations. While detection rates in a natural setting are rarely perfect (Thompson 2002), our model helped identify starting locations for unionid surveys and the methods we employed detected a range of shell sizes, including very small sizes, and a relatively high diversity of species. In conclusion, the HSI models constructed for unionids can be used to locate communities in target systems.

4.6 Acknowledgments

Thank you to the dedicated volunteers who helped with the field work for this project:

Chris Collier, Sara Guiher, Casey Yanos, Jake Kvistad, Wendy Stevens, Marty

Simonson, Kristen Hebebrand, Ben Kuhaneck, David Burton, and Paige Pierce. Funding to create the lake sturgeon habitat suitability index model was provided through a grant from the U.S. Fish and Wildlife Service, #205150.

Table 4.1. Input values for the habitat suitability index model used to delineate high- quality (Suitability Index 0.8 – 1), marginal (S.I. 0.3 – 0.79), or unsuitable (S.I. 0 – 0.29) for unionid communities in the Lower Maumee River.

Habitat Variable Suitability Index Reference Water Depth (m)

0-0.3 0 Morales et al. 2006 0.3-0.6 0.3 Morales et al. 2006 0.6-0.8 0.5 Morales et al. 2006 0.8-1.5 1 Morales et al. 2006 1.5-2.0 0.5 Morales et al. 2006 2.0-10 0.1 Morales et al. 2006 >10 0 Morales et al. 2006 Substrate

Clay 0.3 Grabarkiewicz & Crail 2006 Silt 0.2 Grabarkiewicz & Crail 2006 Sand 1 Morales et al. 2006 Gravel 1 Grabarkiewicz & Crail 2006 Cobble 0.5 Grabarkiewicz & Crail 2006 Boulder 0 Morales et al. 2006 Bedrock 0 Morales et al. 2006 Velocity (m/s)

0-0.01 0 Morales et al. 2006 0.01-0.1 0.3 Morales et al. 2006 0.1-0.15 0.5 Morales et al. 2006 0.15-0.2 1 Morales et al. 2006 0.2-0.6 0.8 Morales et al. 2006 0.6-0.7 0.5 Morales et al. 2006 0.7-1.6 0.3 Morales et al. 2006 >1.6 0 Morales et al. 2006

Table 4.2. List of unionid species surveyed in the Lower Maumee River, OH between July and September 2017. Abundance is the total number of mussels present across all survey quadrats.

Latin Name Common Name Abundance Amblema plicata Threeridge 1 Lasmigona complanata White Heelsplitter 18 Leptodea fragilis Fragile Papershell 15 Obliquaria reflexa Threehorn Wartyback 31 Potamilus alatus Pink Heelsplitter 29 Pyganodon grandis Giant Floater 2 Quadrula pustulosa Pimpleback 33 Quadrula quadrula Mapleleaf 66 Truncilla truncata Deer Toe 48 Utterbackia imbecillis Paper Pondshell 2

Table 4.3. Sampling sites with locations based on nearest river kilometer (rkm), a priori HSI model delineations, Shannon diversity index value, density, richness, and abundance.

Sampling Suitability Shannon Density Number Total Number of RKM Date delineation Diversity (m2) of Species Unionids 9/3/16 23 Good 0.00 0 0 0 9/13/16 25 - 26 Good 0.00 0 0 0 9/28/16 40 - 41 Good 0.00 0 0 0 8/11/16 41 Good 2.63 0.52 7 52 7/20/16 42 - 43 Moderate 5.32 0.44 7 44 8/11/16 41 Moderate 3.77 0.41 7 41 7/21/16 42 - 43 Moderate 4.88 0.21 8 21 7/21/16 42 - 43 Moderate 6.25 0.18 8 18 7/20/16 42 - 43 Moderate 3.38 0.14 5 14 9/28/16 42 Moderate 3.76 0.13 7 13 8/11/16 41 Moderate 3.57 0.05 4 5 8/26/16 48 Moderate 1.47 0.05 2 5 9/2/16 40 - 41 Moderate 2.27 0.05 3 5 7/21/16 42 - 43 Moderate 2.00 0.02 2 2 9/3/16 40 - 41 Moderate 1.00 0.02 1 2 7/20/16 42 - 43 Moderate 1.00 0.01 1 1 8/11/16 42 - 43 Moderate 0.00 0 0 0 8/26/16 48 Moderate 0.00 0 0 0 9/3/16 23 Moderate 0.00 0 0 0 9/13/16 27 Moderate 0.00 0 0 0 9/13/16 25 Moderate 0.00 0 0 0 9/13/16 25 - 26 Moderate 0.00 0 0 0 7/19/16 40 - 41 Poor 5.78 0.18 8 18 7/21/16 42 - 43 Poor 2.00 0.02 2 2 7/23/16 42 - 43 Poor 1.00 0.01 1 1 9/2/16 35 - 36 Poor 1.00 0.01 1 1 7/21/16 42 - 43 Poor 0.00 0 0 0 8/26/16 43 Poor 0.00 0 0 0 9/2/16 35 - 36 Poor 0.00 0 0 0 9/2/16 35 - 36 Poor 0.00 0 0 0 9/2/16 35 - 36 Poor 0.00 0 0 0 9/2/16 40 Poor 0.00 0 0 0 9/13/16 30 Poor 0.00 0 0 0 99

9/13/16 25 - 26 Poor 0.00 0 0 0 Table 4.4. Overview of unionid survey data with habitat delineation representing the suitability index name for each polygon, the number of quadrats sampled within each suitability designation, mean unionid abundance and standard error for all suitability designations, and the mean species richness and standard error.

Habitat No. Delineation Sites Abundance ± S.E. Richness ± S.E. Good 4 13 13 1.75 1.75 Moderate 18 9.5 3.24 3 0.75 Poor 12 1.8 1.48 1 0.66

100

Table 4.5. The Poisson regression (generalized linear model) results comparing unionid abundance and species richness to habitat suitability designations of high-quality, marginal, or unsuitable.

Habitat Delineation Coefficients Significance High-quality 2.56 <0.001 Unionid Marginal -0.31 0.0476 Abundance Unsuitable -1.96 <0.001 High-quality 0.56 0.139 Species 0.56 0.165 Richness Marginal Unsuitable -0.56 0.239

101

Figure 4.1. Our study area consisted of 56-rkm of the lower Maumee River in NW Ohio from the Grand Rapids and Providence low head dams (indicated by the dam icon west of Grand Rapids), to the Audubon Islands at rkm 22 (east of Maumee).

102

Figure 4.2. Estimated habitat suitability indices for unionid mussels in the Maumee River, OH for (A) substrate type (IS), (B) water velocity (IV), and (D) water depth (ID). Habitat suitability indices are ranked from 0 – 1 with 0 – 0.29 representing unsuitable habitat, 0.3 – 0.79 representing marginal habitat, and 0.8 – 1 representing high-quality habitat. Suitability indices were adapted from Morales et al. (2006) and Grabarkiewicz & Crail (2006). 103

Figure 4.3. Survey sites for unionid communities in the Maumee River. Insets display unionid abundance and species richness at selected sites.

104

Chapter 5

Dissertation Conclusion

Biodiversity and ecological function are increasingly threatened by human influences, especially in freshwater systems which host a disproportionate number of species compared to the fraction of space they occupy. Overexploitation of resources and development of natural areas is contributing to an increasing extinction rate for freshwater species, which underpins the need for conservation and sustainability practices to protect natural resources and biodiversity. Simon Stuart, chair of the species survival commission for the International Union for Conservation of Nature from 2008 – 2016 said it best when he proclaimed, "the future of many species is going to depend on reconciling the needs of people and nature, and ensuring economic development and conservation do not undermine each other." One of the ways we can attain this goal is to implement restoration, species reintroduction, and conservation efforts to mitigate population declines, rebuild ecosystem function, and curb extinction rates. This dissertation outlines the development and implementation of habitat suitability index models as tools to assess habitat conditions to support species reintroduction and monitor populations of imperiled species. By identifying the status of habitats and species

105

populations, we can help managers and stakeholders determine the feasibility of investing resources for restoration and reintroduction efforts.

Lake sturgeon (Acipenser fulvescens) are a historically important, imperiled species in need of management efforts to conserve remnant populations, rebuild diminished populations, and reintroduce extirpated stocks. One of the initial priorities to reintroduce a species is to examine if habitat quality and quantity is present in the target system to enable a species to persist. For lake sturgeon, the goal for reintroduction is to build a self-sustaining population of about 1,500 spawning adults in any particular location. The HSI models developed in this dissertation assessed habitat conditions in the

Maumee River where lake sturgeon have been extirpated since the late 1800’s. Using physical habitat characteristics important for spawning adults and age-0 fish (e.g., substrate, water velocity, and water depth), we developed a spatially explicit HSI model to identify areas of good, moderate, or poor habitat for the two life stages and examined the connectivity between optimal spawning locations and age-0 habitat. These models indicated that 156 ha of good spawning habitat, a sufficient area to host the target population of at least 1,500 spawning adults, and 529 ha of good age-0 habitat are present in the lower Maumee River. Furthermore, most good habitat for age-0 fish is located adjacent to and downstream of good spawning areas. This is an important spatial connection between the two habitat types through an ontogenetic shift in the lake sturgeon life cycle and supporting species reintroduction efforts.

A reintroduction plan was created to summarize important elements for successful reintroduction efforts. We outlined a multifaceted approach incorporating biological,

106

managerial, and societal perspectives, to identify potential barriers to reintroduction and highlight direct actions to increase reintroduction success. By incorporating details on current habitat conditions, potential habitat constraints, juvenile rearing and stocking strategies, biological monitoring and evaluation, public education and outreach, regulation and enforcement, and incorporation of long-term management techniques, we provided a guideline for lake sturgeon reintroduction in the Maumee River that can be applied across the Lake Erie basin.

After creating the lake sturgeon HSI model, we aimed to determine if the model structure could be utilized for other species in the Maumee River. We tested model transferability on native unionid communities, another highly imperiled group of organisms. Field surveys were conducted to determine if our HSI model could predict higher unionid abundance and species richness in areas delineated as high-quality habitat and lower abundance and richness in marginal and unsuitable habitats. Using the same model inputs as the sturgeon model, we created an HSI model to identify high-quality, marginal, and unsuitable habitat for unionids in the lower Maumee River. Field surveys of 34 field plots identified 245 individuals representing 10 species, including a State

Threatened species (Obliquaria reflexa) and a State Species of Concern (Truncilla truncata). Analysis revealed a higher abundance of unionids in areas delineated as high- quality habitat compared to marginal with the lowest abundance in unsuitable habitats.

Although our model failed to predict species richness based these habitat delineations, having a tool to identify areas with a high abundance of unionids is important for managers to monitor these imperiled organisms. As unionids are patchy in nature, this

107

model can serve as a tool to help identify potential community locations. The capacity of

HSI models to identify habitats that may host a high abundance of unionids is especially helpful in large river systems as it can identify starting points for surveying unionid communities and help managers monitor population changes that may require conservation action.

5.1 Practical Guidelines & Recommendations

The goal of this dissertation was to create habitat suitability index models to evaluate current habitat conditions in the Maumee River to support restoration work and species monitoring. Habitat suitability index models are a common tool to aid conservation monitoring and reinforce species restoration plans. In this work, we demonstrate how to implement an HSI model for multiple ontogenetic life stages to support management efforts for species reintroduction. By first evaluating the habitat of a target system and ensuring the habitat requirements for multiple life stages are in high quality and quantity, we can better justify resource expenditure to reintroduce an endangered species. We identified that habitat quantity and quality in the Maumee River is likely sufficient to support lake sturgeon reintroduction efforts. Furthermore, this tool, having been successfully transferred to another group of organisms, could also be used to evaluate restoration or population augmentation for species, like other lithophilic spawners, that have similar spawning habitat requirements.

108

5.2 Future Work

Although this work provides support for lake sturgeon reintroduction in the

Maumee River and identifies starting points for unionid community assessments, there is still a lot to learn to inform species conservation efforts. Compared to other lake sturgeon life stages, very little is known about the age-0 life stage especially regarding survival, dispersal, and habitat use after stocking. Therefore, efforts to track recently released fingerling lake sturgeon are needed to provide information on what habitats are used by age-0 lake sturgeon, where and when age-0 fish disperse, survival to subsequent life stages after rearing and reintroduction and, how all of this compares to natural stocks in other systems. Tracking age-0 lake sturgeon post-release with a focus on habitat use and movement would provide critical information for Lake Erie tributaries, as this is the first instance of species reintroduction within the Lake Erie basin. Tracking information for the age-0 life stage can help reconcile discrepancies in the literature on preferred habitat use that often comes from lake sturgeon occupying a diverse array of systems and exhibiting plasticity for habitat preferences depending on available resources.

Furthermore, many species reintroduction programs are unsuccessful due to a lack of knowledge of preferred habitats. By gathering data for life stage specific habitat preferences, especially age-0 fish, we can better understand habitat use and requirements across a spectrum of systems that will help inform habitat suitability index models and reintroduction plans.

Although the HSI model developed for unionid communities accurately predicted higher abundances in areas classified as high-quality habitat, there are some flaws in the

109

both model design and data collection that if addressed, could provide a more precise model that is less intensive to construct. The HSI model initially designed for lake sturgeon was not as accurate in depicting small-scale habitat structures, like what is used by unionids, and misclassified some substrate cells based on interpolation data. For large, mobile species, some misclassifications will not have a significant effect on total habitat suitability. But for a semi-infaunal and patchily distributed organism with a small home range, these small-scale misclassifications have a more significant compared to large- bodied, highly migratory species like sturgeon. I suggest using landscape geomorphology features (i.e., stream gradient, sinuosity, river bank attack angle, etc.), and velocity modeling from discharge data to produce HSI models that would save time on field data collection and more precisely depict habitat conditions for target species.

In order to protect biodiversity and ecosystem function, our society must actively work to implement conservation and sustainability actions that will reconcile economic pressures and ecological integrity. Restoration initiatives, species reintroduction, and conservation efforts are integral parts of mitigating anthropogenic demands and influences, but without public buy-in and strong policy and legislation in place to protect resources and guide sustainable practices, these efforts will not be successful. As emphasized by Pollock et al. (2015), the survival of imperiled species hinges upon public sentiment. Public outreach and education drive the impetus of conservation, restoration, and reintroduction goals, which then in turn influence policy and legislation. To truly work toward conserving biological integrity, we should start with and emphasize public education and outreach. Ecological hotspots, like freshwater ecosystems, require

110

strenuous conservation and restoration efforts to protect biodiversity and ecological function and through vigilant management efforts, like the habitat assessments and population monitoring tools documented in this dissertation, we can reconcile human demands and impacts that threaten our natural resources.

111

References

Auer, N. A. 1996. Importance of habitat and migration to sturgeons with emphasis on

lake sturgeon. Canadian Journal of Fisheries and Aquatic Sciences 53:152-160.

Auer, N. A. 2003. A lake sturgeon rehabilitation plan for Lake Superior. Miscellaneous

Publications. Great Lakes Fishery Commission:1-4.

Auer, N. A., and E. A. Baker. 2002. Duration and drift of larval lake sturgeon in the

Sturgeon River, Michigan. Journal of Applied Ichthyology 18:557-564.

Bauer, G., and K. Wächtler. 2012. Ecology and evolution of the freshwater mussels

Unionoida. Springer Science & Business Media.

Bauman, J. M. 2015. Enhancing the success of Great Lakes lake sturgeon restoration

through development of standard operating procedures for stream-side hatcheries.

Michigan State University, East Lansing, Michigan

Bauman, J. M., B. M. Woodward, E. A. Baker, T. L. Marsh, and K. T. Scribner. 2016.

Effects of Family, Feeding Frequency, and Alternate Food Type on Body Size

and Survival of Hatchery-Produced and Wild-Caught Lake Sturgeon Larvae.

North American Journal of Aquaculture 78:136-144.

Bauman, J. M., E. A. Baker, T. L. Marsh, and K. T. Scribner. 2015. Effects of Rearing

Density on Total Length and Survival of Lake Sturgeon Free Embryos. North

American Journal of Aquaculture 77:444-448. 112

Beamesderfer, R. C., and R. A. Farr. 1997. Alternatives for the protection and restoration

of sturgeons and their habitat. Environmental biology of Fishes 48:407-417.

Benson, A. C., T. M. Sutton, R. F. Elliott, and T. G. Meronek. 2005. Seasonal Movement

Patterns and Habitat Preferences of Age-0 Lake Sturgeon in the Lower Peshtigo

River, Wisconsin. Transactions of the American Fisheries Society 134:1400-

1409.

Bezold, J. D. 2007. Lake Sturgeon Reintroduction in the Coosa River System, Georgia -

Alabama University of Georgia, Athens, Georgia.

Billard, R., and G. Lecointre. 2000. Biology and conservation of sturgeon and paddlefish.

Reviews in Fish Biology and Fisheries 10:355-392.

Birstein, V. J. 1993. Sturgeons and paddlefishes: threatened fishes in need of

conservation. Conservation Biology 7:773-787.

Boase, J. C. 2008. 2008 Annual Report: Evaluating Lake Sturgeon Spawning in the

Maumee River, Ohio. Page 17. US Fish and Wildlife Service.

Bowles, M. L., and C. J. Whelan. 1996. Restoration of endangered species: conceptual

issues, planning and implementation. Cambridge University Press.

Brainwood, M., S. Burgin, and M. Byrne. 2008. The role of geomorphology in

substratum patch selection by freshwater mussels in the Hawkesbury-Nepean

River (New South Wales) Australia. Aquatic Conservation 18:1285-1301.

Brooks, R. P. 1997. Improving habitat suitability index models. Wildlife Society Bulletin

(1973-2006) 25:163-167.

113

Bruch, R., and F. Binkowski. 2002. Spawning behavior of lake sturgeon (Acipenser

fulvescens). Journal of Applied Ichthyology 18:570-579.

Bruch, R., T. Haxton, R. Koenigs, A. Welsh, and S. Kerr. 2016. Status of Lake Sturgeon

(Acipenser fulvescens, Rafinesque 1817) in North America. Journal of Applied

Ichthyology 32:162-190.

Carey, C. S., J. W. Jones, R. S. Butler, and E. M. Hallerman. 2015. Restoring the

endangered oyster mussel (Epioblasma capsaeformis) to the upper Clinch River,

Virginia: an evaluation of population restoration techniques. Restoration Ecology

23:447-454.

Caswell, N., D. Peterson, B. Manny, and G. Kennedy. 2004. Spawning by lake sturgeon

(Acipenser fulvescens) in the Detroit River. Journal of Applied Ichthyology 20:1-

Ceballos, G., P. R. Ehrlich, A. D. Barnosky, A. Garcia, R. M. Pringle, and T. M. Palmer.

2015. Accelerated modern human-induced species losses: Entering the sixth mass

extinction. Science Advances 1:5.

Cech Jr, J. J., and S. I. Doroshov. 2004. Environmental requirements, preferences, and

tolerance limits of North American sturgeons. Pages 73-86. Sturgeons and

paddlefish of North America. Springer.

Chalupnicki, M. A., D. E. Dittman, and D. M. Carlson. 2011. Distribution of lake

sturgeon in New York: 11 years of restoration management. The American

Midland Naturalist 165:364-371.

Chesapeake Technologies, I. 2014. SonarWiz 5. 5.07.0012, Mountain View, CA.

114

Chiasson, W. B., D. L. Noakes, and F. W. H. Beamish. 1997. Habitat, benthic prey, and

distribution of juvenile lake sturgeon (Acipenser fulvescens) in northern Ontario

rivers. Canadian Journal of Fisheries and Aquatic Sciences 54:2866-2871.

Chiotti, J. A., D. Hondorp, R. Drouin, J. C. Boase, C. Holbrook, M. Thomas, T. Wills, E.

F. Roseman, L. Mohr, and C. Krueger. 2016. Dispersal of Lake Sturgeon from a

Connecting Channel: Implications for Restoration in the Great Lakes. American

Fisheries Society 146th Annual Meeting Kansas City, Missouri, August 21-25.

Chiotti, J. A., J. C. Boase, D. W. Hondorp, and A. S. Briggs. 2016a. Assigning Sex and

Reproductive Stage to Adult Lake Sturgeon using Ultrasonography and Common

Morphological Measurements. North American Journal of Fisheries Management

36:21-29.

Chiotti, J. A., J. M. Holtgren, N. A. Auer, and S. A. Ogren. 2008. Lake sturgeon

spawning habitat in the Big Manistee River, Michigan. North American Journal

of Fisheries Management 28:1009-1019.

Chiotti, J. Personal Communication. May 3, 2017.

Chiotti, J., L. Mohr, M. Thomas, J. C. Boase, and B. Manny. 2012. Lake Sturgeon

Population Demographics in the Huron-Erie Corridor, 1996-2012. American

Fisheries Society 142nd Annual Meeting Minneapolis, Minnesota, August 19-23.

Chipps, S. R., R. A. Klumb, and E. B. Wright. 2008. Development and application of

juvenile pallid sturgeon bioenergetics model

115

Chowdhury, G. W., A. Zieritz, and D. C. Aldridge. 2016. Ecosystem engineering by

mussels supports biodiversity and water clarity in a heavily polluted lake in

Dhaka, Bangladesh. Freshwater Science 35:188-199.

Cianfrani, C., L. Maiorano, A. Loy, A. Kranz, A. Lehmann, R. Maggini, and A. Guisan.

2013. There and back again? Combining habitat suitability modelling and

connectivity analyses to assess a potential return of the otter to Switzerland.

Animal Conservation 16:584-594.

Cook, C., D. Morgan, and D. Marshall. 2010. Reevaluating suitable habitat for

reintroductions: lessons learnt from the eastern barred bandicoot recovery

program. Animal Conservation 13:184-195.

Crossman, J. A., P. S. Forsythe, E. A. Baker, and K. T. Scribner. 2009. Overwinter

survival of stocked age-0 lake sturgeon. Journal of Applied Ichthyology 25:516-

521.

Crossman, J. A., K. T. Scribner, D. T. Yen, C. A. Davis, P. S. Forsythe, and E. A. Baker.

2011. Gamete and larval collection methods and hatchery rearing environments

affect levels of genetic diversity in early life stages of lake sturgeon (Acipenser

fulvescens). Aquaculture 310:312-324.

Daugherty, D. J., T. M. Sutton, and R. F. Elliott. 2008. Potential for reintroduction of lake

sturgeon in five northern Lake Michigan tributaries: a habitat suitability

perspective. Aquatic Conservation: Marine and Freshwater Ecosystems 18:692-

702.

116

Daugherty, D. J., T. M. Sutton, and R. F. Elliott. 2009. Suitability Modeling of Lake

Sturgeon Habitat in Five Northern Lake Michigan Tributaries: Implications for

Population Rehabilitation. Restoration Ecology 17:245-257.

Deslauriers, D., L. Heironimus, and S. R. Chipps. 2016. Lethal thermal maxima for age-0

pallid and shovelnose sturgeon: Implications for shallow water habitat restoration

River Research and Applications 32:1872-1878.

Dittman, D. E. C., Marc A.; Johnson, James H.; Snyder, James. 2015. Reintroduction of

Lake Sturgeon (Acipenser fulvescens) into the St. Regis River, NY: Post-Release

Assessment of Habitat Use and Growth. Northeastern Naturalist 22:704-716.

Dittman, D. E., and E. C. Zollweg. 2006. Assessment of Habitat Use by Experimentally

Stocked Juvenile Lake Sturgeon. Page 50 in U. S. G. Survey, editor. Technical

Report. Environmental Protection Agency Great Lakes National Program Office,

Cortland, New York.

Dudgeon, D., A. H. Arthington, M. O. Gessner, Z. I. Kawabata, D. J. Knowler, C.

Lévêque, R. J. Naiman, A. H. Prieur‐Richard, D. Soto, and M. L. Stiassny. 2006.

Freshwater biodiversity: importance, threats, status and conservation challenges.

Biological reviews 81:163-182.

Dunham, J., K. Gallo, D. Shively, C. Allen, and B. Goehring. 2011. Assessing the

feasibility of native fish reintroductions: a framework applied to threatened bull

trout. North American Journal of Fisheries Management 31:106-115.

Eggold, B., M. Baumgartner, S. Fajfer, J. M. Holtgren, and E. A. Baker. 2012. Great

Lakes Fishery Trust Final Report 2005.671.

117

ESRI. 2011. ArcGIS Desktop. 10.2. Environmental Systems Research Institute,

Redlands, CA.

Farrell, J. M., R. T. Colesante, D. E. Dittman, and J. H. Johnson. 2009. Lake Sturgeon

Population Enhancement as a Strategy for Improvement of Ecosystem Function

and Controlling Invasive Species. Final Report Submitted to the Fish

Enhancement Mitigation and Research Fund US Fish and Wildlife Service New

York Field Office and the Fisheries Advisory Committee.

Fisk, J., T. J. Kwak, and R. Heise. 2014. Modelling riverine habitat for robust redhorse:

assessment for reintroduction of an imperilled species. Fisheries Management and

Ecology 21:57-67.

Fortin, R., J. D'Amours, and S. Thibodeau. 2002. Effets de l’améagenement d’un

nouveau secteur de frayère sur l’utilisation du milieu en période de fraie et sur le

succès de reproduction de l’esturgeon jaune (Acipenser fulvescens) à la frayère de

la rivière des Prairies., Hydro Québec et la Société de la faune et des parcs du

Québec, et Université du Québec à Montréal.

Friday, M. J. 2006. An assessment of growth of young-of-the-year lake sturgeon in the

Kaministiquia River. Agency Report Upper Great Lakes Management Unit.

Ontario Ministry of Natural Resources, Thunder Bay, Ontario.

Galarowicz, T. 2003. Conservation assessment for lake sturgeon (Acipenser fulvescens).

USDA Forest Service, Mount Pleasant, MI, USA.

118

Gangloff, M. M., and J. W. Feminella. 2007. Stream channel geomorphology influences

mussel abundance in southern Appalachian streams, USA. Freshwater Biology

52:64-74.

Gangloff, M. M., G. J. Edgar, and B. Wilson. 2016. Imperilled species in aquatic

ecosystems: emerging threats, management and future prognoses. Aquatic

Conservation-Marine and Freshwater Ecosystems 26:858-871.

George, A. L., B. R. Kuhajda, J. D. Williams, M. A. Cantrell, P. L. Rakes, and J. Shute.

2009. Guidelines for propagation and translocation for freshwater fish

conservation. Fisheries 34:529-545.

Goodyear, C. D. 1982. Atlas of the spawning and age-0 areas of Great Lake fishes. US

Fish and Wildlife Service.

Grabarkiewicz, J., and T. Crail. 2006. Freshwater mussels of the Maumee drainage.

Lucas Soil and Water Conservation District.

Gutierrez, J. L., C. G. Jones, D. L. Strayer, and O. O. Iribarne. 2003. Mollusks as

ecosystem engineers: The role of shell production in aquatic habitats. Oikos

101:79-90.

Haag, W. R., and J. D. Williams. 2014. Biodiversity on the brink: an assessment of

conservation strategies for North American freshwater mussels. Hydrobiologia

735:45-60.

Harkness, W. J. K., and J. R. Dymond. 1961. The lake sturgeon: the history of its fishery

and problems of conservation. Fish & Wildlife Branch, Ontario Department of

Lands and Forests.

119

Haxton, T. J., and C. S. Findlay. 2008. Variation in lake sturgeon (Acipenser fulvescens)

abundance and growth among river reaches in a large regulated river. Canadian

Journal of Fisheries and Aquatic Sciences 65:645-657.

Haxton, T., G. Whelan, and R. Bruch. 2014. Historical biomass and sustainable harvest

of Great Lakes lake sturgeon (Acipenser fulvescens Rafinesque, 1817). Journal of

Applied Ichthyology 30:1371-1378.

Hay-Chmielewski, E. M., and G. E. Whelan. 1997. Lake Sturgeon rehabilitation strategy.

Michigan Department of Natural Resources

Hayes, D. B., and D. C. Caroffino. 2012. Michigan's Lake Sturgeon rehabilitation

strategy. Michigan Department of Natural Resources, Fisheries Special Report 62.

Hayes, M. F., and N. P. Banish. 2017. Translocation and reintroduction of native fishes: a

review of bull trout Salvelinus confluentus with applications for future

reintroductions. Endangered Species Research 34:191-209.

Hegeman, E. E., S. W. Miller, and K. E. Mock. 2014. Modeling freshwater mussel

distribution in relation to biotic and abiotic habitat variables at multiple spatial

scales. Canadian Journal of Fisheries and Aquatic Sciences 71:1483-1497.

Herdendorf, C. E. 1990. Great lakes estuaries. Estuaries 13:493-503.

Holtgren, J. M., and N. A. Auer. 2004. Movement and habitat of juvenile lake sturgeon

(Acipenser fulvescens) in the Sturgeon River/Portage Lake system, Michigan.

Journal of Freshwater Ecology 19:419-432.

120

Holtgren, J. M., S. A. Ogren, A. J. Paquet, and S. Fajfer. 2007. Design of a portable

streamside rearing facility for lake sturgeon. North American Journal of

Aquaculture 69:317-323.

Homola, J. J., K. T. Scribner, E. A. Baker, and N. A. Auer. 2010. Genetic assessment of

straying rates of wild and hatchery reared lake sturgeon (Acipenser fulvescens) in

Lake Superior tributaries. Journal of Great Lakes Research 36:798-802.

Hornbach, D. J., and T. Deneka. 1996. A comparison of a qualitative and a quantitative

collection method for examining freshwater mussel assemblages. Journal of the

North American Benthological Society:587-596.

Inoue, K., K. Stoeckl, and J. Geist. 2017. Joint species models reveal the effects of

environment on community assemblage of freshwater mussels and fishes in

European rivers. Diversity and Distributions 23:284-296.

Johnson, J. H., S. R. LaPan, R. M. Klindt, and A. Schiavone. 2006. Lake sturgeon

spawning on artificial habitat in the St Lawrence River. Journal of Applied

Ichthyology 22:465-470.

Kempinger, J. 1988. Spawning and early life history of Lake Sturgeon in the Lake

Winnebago system, Wisconsin. American Fisheries Society, S 5:110-122.

Kempinger, J. J. 1996. Habitat, growth, and food of young lake sturgeons in the Lake

Winnebago system, Wisconsin. North American Journal of Fisheries Management

16:102-114.

121

Kimanzi, J. K., R. A. Sanderson, and S. P. Rushton. 2014. Habitat suitability modelling

and implications for management of roan antelopes in Kenya. African journal of

ecology 52:111-121.

Kirsch, P. H. 1895. A Report upon investigations in the Maumee River Basin during the

Summer of 1983 Bulletin of the U.S. Fish Commission

Knudson, M. D., J. A. VanLooy, and M. J. Hill. 2015. A Habitat Suitability Index (HSI)

for the Western Prairie Fringed Orchid (Platanthera praeclara) on the Sheyenne

National Grassland, North Dakota, USA. Ecological Indicators 57:536-545.

LaHaye, M., A. Branchaud, M. Gendron, R. Verdon, and R. Fortin. 1992. Reproduction,

early life history, and characteristics of the spawning grounds of the lake sturgeon

(Acipenser fulvescens) in Des Prairies and L'Assomption rivers, near Montreal,

Quebec. Canadian Journal of Zoology 70:1681-1689.

LaHaye, M., S. Desloges, C. Cote, J. Deer, S. Phillips, B. Giroux, S. Clermont, and P.

Dumont. 2003. Location of lake sturgeon (Acipenser fulvescens) spawning

grounds in the upper part of the Lachine rapids (St. Lawrence River). Société de

la faune et des parcs du Québec, Direction de l’aménagement de la faune de

Montréal, de Laval et de la Montérégie, Longueuil, Montréal, Québec.

Langlois, T. H. 1954. The Western End of Lake Erie and Its Ecology. Soil Science 78:83.

Lopes-Lima, M., A. Teixeira, E. Froufe, A. Lopes, S. Varandas, and R. Sousa. 2014.

Biology and conservation of freshwater bivalves: past, present and future

perspectives. Hydrobiologia 735:1-13.

122

Lopes-Lima, M., R. Sousa, J. Geist, D. C. Aldridge, R. Araujo, J. Bergengren, Y.

Bespalaya, E. Bodis, L. Burlakova, D. Van Damme, K. Douda, E. Froufe, D.

Georgiev, C. Gumpinger, A. Karatayev, U. Kebapci, I. Killeen, J. Lajtner, B. M.

Larsen, R. Lauceri, A. Legakis, S. Lois, S. Lundberg, E. Moorkens, G. Motte, K.-

O. Nagel, P. Ondina, A. Outeiro, M. Paunovic, V. Prie, T. von Proschwitz, N.

Riccardi, M. Rudzite, M. Rudzitis, C. Scheder, M. Seddon, H. Sereflisan, V.

Simic, S. Sokolova, K. Stoeckl, J. Taskinen, A. Teixeira, F. Thielen, T.

Trichkova, S. Varandas, H. Vicentini, K. Zajac, T. Zajac, and S. Zogaris. 2017.

Conservation status of freshwater mussels in Europe: state of the art and future

challenges. Biological Reviews (Cambridge) 92:572-607.

Lucy, F., L. Burlakova, A. Karatayev, S. Mastitsky, and D. Zanatta. 2014. Zebra mussel

impacts on unionids: a synthesis of trends in North America and Europe. Quagga

and Zebra Mussels: Biology, Impacts, and Control, 2nd ed. CRC Press, Boca

Raton:623-646.

Ludwig, A. 2006. A sturgeon view on conservation genetics. European Journal of

Wildlife Research 52:3-8.

Lydeard, C., R. H. Cowie, W. F. Ponder, A. E. Bogan, P. Bouchet, S. A. Clark, K. S.

Cummings, T. J. Frest, O. Gargominy, and D. G. Herbert. 2004. The global

decline of nonmarine mollusks. Bioscience 54:321-330.

Lyons, J., and J. S. Stewart. 2014. Predicted effects of future climate warming on thermal

habitat suitability for Lake Sturgeon (Acipenser fulvescens, Rafinesque, 1817) in

rivers in Wisconsin, USA. Journal of Applied Ichthyology 30(6): 1508-1513.

123

Lyons, J., T. Zorn, J. Stewart, P. Seelbach, K. Wehrly, and L. Wang. 2009. Defining and

Characterizing Coolwater Streams and Their Fish Assemblages in Michigan and

Wisconsin, USA. North American Journal of Fisheries Management 29:1130-

1151.

Lyttle, M. 2008. Spawning Habitat Suitability for Walleye and Lake Sturgeon in the

Missisquoi River. Prepared for the Lake Champlain Fishery Technical

Committee. Prepared by the US Fish and Wildlife Service.

Manny, B., and G. Kennedy. 2002. Known lake sturgeon (Acipenser fulvescens)

spawning habitat in the channel between lakes Huron and Erie in the Laurentian

Great Lakes. Journal of Applied Ichthyology 18:486-490.

Mapes, R. L., M. R. DuFour, J. J. Pritt, and C. M. Mayer. 2015. Larval fish assemblage

recovery: a reflection of environmental change in a large degraded river.

Restoration Ecology 23:85-93.

Master, L. L., B. A. Stein, L. S. Kutner, and G. A. Hammerson. 2000. Vanishing assets:

conservation status of US species. Precious heritage: the status of biodiversity in

the United States. Oxford University Press, New York:93-118.

McDougall, C., D. Pisiak, C. Barth, M. Blanchard, D. MacDonell, and D. Macdonald.

2014. Relative recruitment success of stocked age‐1 vs age‐0 lake sturgeon

(Acipenser fulvescens Rafinesque, 1817) in the Nelson River, northern Canada.

Journal of Applied Ichthyology 30:1451-1460.

Meador, J. R., J. T. Peterson, and J. M. Wisniewski. 2011. An evaluation of the factors

influencing freshwater mussel capture probability, survival, and temporary

124

emigration in a large lowland river. Journal of the North American Benthological

Society 30:507-521.

Miller, A. C., and B. S. Payne. 1993. Qualitative versus quantitative sampling to evaluate

population and community characteristics at a large-river mussel bed. American

Midland Naturalist:133-145.

Minckley, W. 1995. Translocation as a tool for conserving imperiled fishes: experiences

in western United States. Biological Conservation 72:297-309.

Mohseni, O., H. G. Stefan, and J. G. Eaton. 2003. Global warming and potential changes

in fish habitat in US streams. Climatic change 59:389-409.

Mueller, Z. P. 2008. Feasibility Study of Removing the Grand Rapids-Providence Dams,

Maumee River (NW Ohio) Based on HEC-RAS Models. Bowling Green State

University Bowling Green, OH

N.N.M.C.C. National Native Mussel Conservation Committee 1998. National Strategy

for the Conservation of Native Freshwater Mussels. Journal of Shellfish Research

17:1419-1428.

Naimo, T. J. 1995. A review of the effects of heavy metals on freshwater mussels.

Ecotoxicology 4:341-362.

National Ballast Information Clearinghouse 2016. NBIC Online Database. Electronic

publication, Smithsonian Environmental Research Center & United States Coast

Guard. Available from http://invasions.si.edu/nbic/search.html; searched on 13

February 2017.

125

Newton, T. J., D. A. Woolnough, and D. L. Strayer. 2008. Using landscape ecology to

understand and manage freshwater mussel populations. Journal of the North

American Benthological Society 27:424-439.

Obermeyer, B. K. 1998. A comparison of quadrats versus timed snorkel searches for

assessing freshwater mussels. The American midland naturalist 139:331-339.

Ohio DNR. Ohio's Listed Species. Page 10 in Ohio Department of Natural Resources,

Division of Wildlife, editor.

Peake, S. 1999. Substrate preferences of juvenile hatchery-reared lake sturgeon,

Acipenser fulvescens. Environmental biology of Fishes 56:367-374.

Peterson, D. L., P. Vecsei, and C. A. Jennings. 2007. Ecology and biology of the lake

sturgeon: a synthesis of current knowledge of a threatened North American

Acipenseridae. Reviews in Fish Biology and Fisheries 17:59-76.

Pikitch, E. K., P. Doukakis, L. Lauck, P. Chakrabarty, and D. L. Erickson. 2005. Status,

trends and management of sturgeon and paddlefish fisheries. Fish and Fisheries

6:233-265.

Pollick, S. 2001. Another sturgeon caught, fueling hopes of resurgence. The Toledo

Blade. http://www.toledoblade.com/frontpage/2001/01/25/Another-sturgeon-

caught-fueling-hopes-of-resurgence.html, Toledo, Ohio

Pollock, M. S., M. Carr, N. M. Kreitals, and I. D. Phillips. 2015. Review of a species in

peril: what we do not know about lake sturgeon may kill them. Environmental

Reviews 23:30-43.

126

Powers, J., S. K. Brewer, J. M. Long, and T. Campbell. 2015. Evaluating the use of side-

scan sonar for detecting freshwater mussel beds in turbid river environments.

Hydrobiologia 743:127-137.

Quinlan, E., C. Gibbins, I. Malcolm, R. Batalla, D. Vericat, and L. Hastie. 2015. A

review of the physical habitat requirements and research priorities needed to

underpin conservation of the endangered freshwater pearl mussel Margaritifera

margaritifera. Aquatic Conservation-Marine and Freshwater Ecosystems 25:107-

124.

R Corp Team. 2017. R: A language and environment for statistical computing. R

Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-

project.org/.

Ricciardi, A., and J. B. Rasmussen. 1999. Extinction rates of North American freshwater

fauna. Conservation Biology 13:1220-1222.

Richards, R. P., D. B. Baker, J. P. Crumrine, J. W. Kramer, D. E. Ewing, and B. J.

Merryfield. 2008. Thirty-year trends in suspended sediment in seven Lake Erie

tributaries. Journal of Enviornmental Quality 37(5): 1894-1908.

Ries, P., N. R. De Jager, S. Zigler, and T. Newton. 2016. Spatial patterns of native

freshwater mussels in the Upper Mississippi River. Freshwater Science 35:934-

947.

Rochard, E., G. Castelnaud, and M. Lepage. 1990. Sturgeons (Pisces: Acipenseridae);

threats and prospects. Journal of Fish Biology 37:123-132.

127

Roseman, E. F., B. Manny, J. Boase, M. Child, G. Kennedy, J. Craig, K. Soper, and R.

Drouin. 2011. Lake sturgeon response to a spawning reef constructed in the

Detroit river. Journal of Applied Ichthyology 27:66-76.

Sardella, B. A., E. Sanmarti, and D. Kultz. 2008. The acute temperature tolerance of

green sturgeon (Acipenser medirostris) and the effect of environmental salinity.

Journal of Experimental Zoology 309:477-483.

Schram, S. T., J. Lindgren, and L. M. Evrard. 1999. Reintroduction of lake sturgeon in

the St. Louis River, western Lake Superior. North American Journal of Fisheries

Management 19:815-823.

Schueller, A. M., and D. B. Hayes. 2010. Minimum viable population size for lake

sturgeon (Acipenser fulvescens) using an individual-based model of demographics

and genetics. Canadian Journal of Fisheries and Aquatic Sciences 68:62-73.

Scott, W. B., and E. J. Crossman. 1973. Freshwater fishes of Canada. Bull. Fish. Res.

Board Can.:184-184.

Seddon, P. J. 1999. Persistence without intervention: assessing success in wildlife

reintroductions. Trends in Ecology & Evolution 14:503-503.

Shaw, S. L. 2010. Lake Sturgeon (Acipenser fulvescens) population attributes,

reproductive structure, and distribution in Namakan Reservoir, Minnesota and

Ontario. South Dakota State University, Brookings, South Dakota.

Shute, J., P. L. Rakes, and P. W. Shute. 2005. Reintroduction of four imperiled fishes in

Abrams Creek, Tennessee. Southeastern Naturalist 4:93-110.

128

Smith, D. R., R. F. Villella, and D. P. Lemarié. 2001. Survey protocol for assessment of

endangered freshwater mussels in the Allegheny River, Pennsylvania. Journal of

the North American Benthological Society 20:118-132.

Smith, H. M., and M.-M. Snell. 1891. Review of the Fisheries of the Great Lakes in

1885. Washington.

Smith, K. 2010. Lake Sturgeon Rehabilitation in the Kalamazoo River. Page 10 in

Michigan Department of Natural Resources, editor.

Stein, B. A., L. S. Kutner, and J. S. Adams. 2000. Precious heritage: the status of

biodiversity in the United States. Oxford University Press on Demand.

Strayer, D. L., and D. Dudgeon. 2010. Freshwater biodiversity conservation: recent

progress and future challenges. Journal of the North American Benthological

Society 29:344-358.

Strayer, D. L., J. A. Downing, W. R. Haag, T. L. King, J. B. Layzer, T. J. Newton, and J.

S. Nichols. 2004. Changing perspectives on pearly mussels, North America's most

imperiled animals. Bioscience 54:429-439.

Thompson, S. K. 2002. Sampling 2nd Edition. John Wiley & Sons, New York

Threader, R. W., R. J. Pope, and P. R. H. Schaap. 1998. Development of a habitat

suitability index model for lake sturgeon (Acipenser fulvescens). Ontario

Hydroelectric

Tody, W. 1974. Whitefish, sturgeon, and the early Michigan commercial fishery.

Trautman, M. B. 1981. The fishes of Ohio: with illustrated keys. Ohio State University

Press.

129

U.S. Army Corp of Engineers. 2015. Toledo, OH Harbor.

http://www.lrb.usace.army.mil/Portals/45/docs/ProjFact/FEB%202016%20Congr

essionals/Toledo_Harbor-OH09.pdf

U.S. Army Corp of Engineers. 2016. HEC-RAS 5.1.in I. f. W. R. H. E. Center, editor.,

Davis, CA.

U.S. Fish and Wildlife Service .1980. Habitat evaluation procedures. Ecological Service

Manual, Bd. 102, Washington DC.

Vaughn, C. C., and C. C. Hakenkamp. 2001. The functional role of burrowing bivalves in

freshwater ecosystems. Freshwater Biology 46:1431-1446.

Vaughn, C. C., K. B. Gido, and D. E. Spooner. 2004. Ecosystem processes performed by

unionid mussels in stream mesocosms: species roles and effects of abundance.

Hydrobiologia 527:35-47.

Watters, G. T., M. A. Hoggarth, and D. H. Stansbery. 2009. The freshwater mussels of

Ohio. Ohio State University Press Columbus, Ohio.

Welsh, A. B. 2010. Genetic guidelines for the stocking of lake sturgeon (Acipenser

fulvescens) in the Great Lakes basin. Great Lakes Fishery Commission.

White, G. C., and K. P. Burnham. 1999. Program MARK: survival estimation from

populations of marked animals. Bird Study 46:S120-S139.

Williams, J. D., M. L. Warren Jr, K. S. Cummings, J. L. Harris, and R. J. Neves. 1993.

Conservation status of freshwater mussels of the United States and Canada.

Fisheries 18:6-22.

130

Wilson, J. A., and R. S. Mckinley. 2004. Distribution, habitat, and movements. Pages 40-

72. Sturgeons and paddlefish of North America. Springer.

Ziegeweid, J. R., C. A. Jennings, and D. L. Peterson. 2008. Thermal maxima for juvenile

shortnose sturgeon acclimated to different temperatures Environmental biology of

Fishes 82:299-307.

131

Appendix A

Input Values for Lake Sturgeon Habitat Suitability Index Models

This Appendix summarizes the habitat characteristics and corresponding suitability index values used to inform each lake sturgeon habitat suitability index model. Corresponding references are cited to support our decision for suitability index value.

Suitability Life Stage Habitat Variable Reference Index Spawning Adult Substrate

Clay 0 Threader et al. 1998

Silt 0 Threader et al. 1998

Sand 0.3 Threader et al. 1998

132

LaHaye et al. 1992, Billard & Lecointre 2000, Manny & Gravel 1 Kennedy 2002, Lyttle 2008, Shaw 2010

Scott & Crossman 1973, Threader 1998 et al., Manny & Cobble 1 Kennedy 2002, Lyttle 2008, Shaw 2010

Scott & Crossman 1973, Boulder 1 Threader 1998 et al., Lyttle 2008;

Bedrock 0.3 Threader et al. 1998

Water Depth (m)

0-0.3 0.1 Threader et al. 1998

Harkness & Dymond 1963, Scott & Crossman 1973, Threader 1998 et al., LaHay et al 2003, 0.3-3.0 1 Wilson & Mckinley 2003, Chiotti et al. 2008, Lyttle 2008, Shaw 2010

Scott & Crossman 1973, 3.0-6.0 1 Threader 1998 et al., Dick et al. 2006, Shaw 2010

6.0-8.0 0.5 Threader et al. 1998

133

Threader et al. 1998, Manny & 8.0-12 0.4 Kennedy 2002

12.0 - 18.0 0.3 Threader et al. 1998

> 18 0.1 Threader et al. 1998

Water Velocity (m/s)

0 0.01 Threader et al. 1998

Kempinger 1988, Threader et al. 0.1 0.8 1998

LaHaye et al. 1992, Threader et al. 1998, Caswell et al. 2004, 0.3 -1.5 1 Johnson et al. 2006, Peterson et al. 2006, Chiotti et al. 2008

Threader et al. 1998, LaHaye et 1.5 - 1.77 0.8 al. 2003,

>1.77 0.01 Threader et al. 1998

Total Spawning Area (m2)

Bruch and Binkowski 2002, <13 m2 per female or < 700 0.29 Fortin et al. 2002 in Dick et al. m2 total 2006

Bruch and Binkowski 2002, >13 m2 per female or > 700 1 Fortin et al. 2002 in Dick et al. m2 total 2006

Age-0 Substrate

134

Threader 1998 et al., Chiasson et Clay 0.4 al 1997

Silt 1 Threader et al. 1998

Kempinger 1996, Threader 1998 et al., Peake 1999 , Holtgren & Sand 1 Auer 2004, Benson et al. 2005, Dittman & Zollweg 2006

Threader 1998 et al., Holtgren & Gravel 1 Auer 2004;

Cobble 0.8 Threader et al. 1998

Boulder 0.5 Threader et al. 1998

Bedrock 0.2 Threader et al. 1998

Water Depth (m)

0-0.2 0.1 Threader et al. 1998

Kempinger 1996, Benson et al. 0.2-2.0 1 2005, Friday 2006

Threader et al. 1998, Dittman & 2.0-8.0 1 Zollweg 2006

Threader et al. 1998, Daugherty 8.0-12 0.7 et al. 2008

Threader et al. 1998, Holtgren & >12 0.29 Auer 2004, Barth et al. 2009, Boase et al. 2014, Haxton 2011

135

Water Velocity (m/s)

Threader et al. 1998, Dittman & 0 - 0.1 0.8 Zollweg 2006

Threader et al. 1998, Benson 0.1 - 0.5 1 2005, Dittman & Zollweg 2006

0.5 - 0.7 0.7

Threader et al. 1998, Billard and >0.7 0.1 Lecointre 2001, Benson et al. 2005

136

Appendix B

Potential Release Sites in the Maumee River for Age-0, Hatchery-Reared Lake Sturgeon

This Appendix a summary of six potential release sites for age-0 lake sturgeon and incorporates details for each release site including: location (latitude and longitude coordinates), if there is adjacent ‘good’ habitat (as delineated by the habitat suitability index model), the downstream distance to the river mouth (measured in river kilometers), if there is space to host a release ceremony and sufficient parking for a release ceremony, and any additional specifications that may be insightful for hosting a release ceremony at each site.

137

138

139

140

141

142

143