UNIVERSITY OF MICHIGAN SCHOOL OF NATURAL RESOURCES & ENVIRONMENT Restoring the Shiawassee Flats Estuarine Gateway to Saginaw Bay Prepared by: Janet Buchanan, Seta Chorbajian, Andrea Dominguez, Brandon Hartleben, Brianna Knoppow, Joshua Miller, Caitlin Schulze, Cecilia Seiter with historical land use analyses by Yohan Chang A project submitted in partial fulfillment of the requirements for the degree of Master of Science at the University of Michigan April 2013 Client: Shiawassee National Wildlife Refuge Faculty advisors: Dr. Michael J. Wiley, Dr. Sara Adlerstein-Gonzalez, Dr. Kurt Kowalski (USGS-GLSC) Preface In 2011, the U.S. Fish & Wildlife Service and Ducks Unlimited received a $1.5 million Sustain Our Great Lakes grant for the first phase of a wetland restoration project at the Shiawassee National Wildlife Refuge, outside Saginaw, Michigan. The ambitious project seeks to hydrologically reconnect a 2,260-acre complex of bottomland farm fields and diked wetlands to the dynamic river systems surrounding the Refuge. The goals of this restoration are to provide fish, birds, and insects with access to a large, restored wetland complex both through hydrologic reconnection and wetland restoration; and to contribute to the delisting of at least three of the Beneficial Use Impairments in the Saginaw River/Bay Area of Concern, just downstream of the Refuge. Phase I of the restoration project involves the conversion of 940 acres of former farmland, now owned by the Refuge, to ecologically productive wetland, and its hydrologic reconnection to the Shiawassee and Flint Rivers. The grant for Phase I included enough funds to complete the design, engineering, and implementation of the project. However, there were no funds allocated for pre-or post-construction monitoring, nor was it clear how the restoration work would be evaluated after its completion. The Refuge recognized that ecological monitoring of a restored area is vital for evaluating the progress of the restoration toward its stated ecological goals, such as increasing fish populations, lowering water pollutant levels, and increasing biological productivity. In early 2012, Refuge and USGS staff proposed a project to the University of Michigan’s School of Natural Resources & Environment which would involve gathering baseline ecological data at the restoration site, providing recommendations for a monitoring plan, and integrating the restoration into the history and social context of the Refuge and the Saginaw Bay region. Over the next 18 months, our team gathered data in the field, investigated past restoration projects to serve as case studies, and researched restoration and monitoring practices. The purpose of our master’s project work is to give the Refuge a larger framework from which to evaluate the efforts of Phase I of the restoration project and a framework for strategically planning future restoration. Our work provides the Refuge staff with ecological baseline data which will help them to design a strategic monitoring plan. Our work also examines case studies of restoration on National Wildlife Refuges and explores opportunities for collaboration with partners in the Saginaw Bay area. Each section of this report concludes with recommendations for the Refuge. At this writing, in April 2013, the design for Phase I of the reconnection project has been finalized and approved, and the project is moving into the permitting process. We hope that our work will aid the Refuge in designing a monitoring plan for the areas restored in Phase I, and contribute to the overall success of the restoration project. ii Acknowledgments Our master’s project team would first like to acknowledge our project advisors: Dr. Michael J. Wiley and Dr. Sara Adlerstein-Gonzalez of the University of Michigan School of Natural Resources & Environment, and Dr. Kurt Kowalski at the USGS Great Lakes Science Center, for their guidance, encouragement, tireless editing and their invaluable technical expertise. The staff of the Shiawassee National Wildlife Refuge, particularly Refuge Manager Steve Kahl, Refuge Wildlife Biologist Eric Dunton, Visitor Services Manager Lionel Grant, and Federal Wildlife Officer Ryan Pauly, provided us with access to the Refuge and its resources to perform our work. Dr. Steve Yaffee, also of the University Of Michigan School of Natural Resources & Environment, helped us in the initial project phases, and provided insight into adaptive management. The amount of field data in this project could not have been collected and analyzed by our team alone. Aubrey Scott helped us throughout the summer of 2012, and Mike Eggleston, Natalie Arnold, Zachary Aubrecht, David Rosier, Andy Layman, and Jenny Pfaff helped us complete our sampling. To analyze aquatic macroinvertebrate data, our team used rarefaction software created by Dr. Steven Holland of the UGA Stratigraphy Lab and available at http://strata.uga.edu/software/. Kyung-Seo Park provided assistance with macroinvertebrate identification. Our team also owes thanks to the many interviewees who gave of their time and expertise in fleshing out case studies of restoration on National Wildlife Refuges: John Bourgeois, Dane Cramer, Ron Huffman, Burke Jenkins, Allison Krueger, Jason Lewis, Mendel Stewart, Laura Valoppi, and Joann Van Aken. We are also deeply grateful to the interviewees from partner organizations in the Saginaw Bay area: Barb Avers, Dane Cramer, Mary Fales, Todd Hogrefe, Mike Kelly, Kurt Kowalski, Helen Taylor, and Michelle Selzer. This project was made possible by funding from the SNRE Master’s Project & Practicum fund through Rackham Graduate School, University of Michigan, the Shiawassee National Wildlife Refuge, the USGS Great Lakes Science Center, and Professor Wiley. iii Executive Summary In 2011, the U.S. Fish & Wildlife Service and Ducks Unlimited received a $1.5 million Sustain Our Great Lakes grant for the first phase of a wetland restoration project at the Shiawassee National Wildlife Refuge, outside Saginaw, Michigan. Phase I of the restoration seeks to reconnect 994 acres of former farmland to the natural, dynamic hydrology of the Shiawassee River, which flows through the Refuge. In 2012, staff at the Shiawassee National Wildlife Refuge contacted a team of master’s degree students at the University of Michigan School of Natural Resources and Environment and asked for an assessment of baseline conditions at the restoration site before the restoration project begins. The Refuge also asked for information about strategies used in other wetland restoration projects and about partners who might contribute to future restoration efforts at the Refuge. This report, organized into three sections, is the outcome of the team’s research. Part 1: Understanding the Past provides a brief history of the Flats and the Refuge, summarizing the key human and environmental factors which shaped their current conditions. • Saginaw County has experienced a 72% reduction in forests and a 96% reduction in wetlands since 1830. These losses were mirrored by dramatic increases in agricultural and urban land cover during this same time period. • The construction of drains, dikes, levees, and water control structures throughout the Flats has drastically altered the main channel position and sinuosity of the Shiawassee River and disrupted the natural flow regimes. The Flint and Bad Rivers also show extensive channel modifications near their confluence with the Shiawassee River. Part 2: Assessing the Present describes the current ecological conditions at the Refuge, including the restoration site, based on field data collected by the team in 2012. To collect these data, a fish community survey, an aquatic macroinvertebrate community survey, a vegetation survey, and water quality testing were conducted. • The fish community of the Shiawassee River is seasonally variable and distinct from the managed units surveyed in 2012, which exhibited a lack of migratory fishes and a predominance of sunfishes. Post-restoration fish monitoring during seasonal migrations and late summer would help evaluate improvements in richness of migratory and floodplain species within the Refuge. • The vegetation within the targeted restoration site and is primarily composed of weedy species. Annual vegetation monitoring by both ground sampling and remote sensing of community structure and composition could be used to assess changes in the plant community after restoration. • Aquatic macroinvertebrate species richness was greatest in the Grefe Pool, a currently restored and managed diked wetland. All three macrohabitats sampled for macroinvertebrates indicated a macroinvertebrate community with high tolerance to nutrient loading and low dissolved oxygen. Post-restoration monitoring could compare iv macroinvertebrate species richness in the restoration site to established wetland units like Grefe Pool. • Hydrologic analysis suggested that, during periods of low flow, significant discharge was released into the Saginaw River from storage in the wetlands of the Flats, exceeding or that measured from tributary river inputs. Further studies should be conducted to distinguish between low flow inputs from hydrologic storage in the Flats versus urban inputs from the city of Saginaw, directly downstream of the Flats. • Total reactive phosphorus loads were on average larger in the Saginaw River than the sum of phosphorus inputs from rivers entering the Saginaw. This indicates that the Flats themselves may be contributing available phosphorus to the Saginaw River, possibly due