M.L. 2013 Minnesota Aquatic Invasive Species Research Center Subproject Abstract For the Period Ending June 30, 2019 SUBPROJECT TITLE: MAISRC Subproject 8: Risk assessment, control, and restoration research on aquatic invasive plant species SUBPROJECT MANAGER: Daniel Larkin AFFILIATION: University of Minnesota MAILING ADDRESS: 135 Skok Hall, 2003 Upper Buford Circle CITY/STATE/ZIP: St. Paul, MN 55108 PHONE: 612-625-6350 E-MAIL: [email protected] WEBSITE: http://larkinlab.cfans.umn.edu/ FUNDING SOURCE: Environment and Natural Resources Trust Fund (ENRTF) LEGAL CITATION: M.L. 2013, Chp. 52, Sec. 2, Subd. 06a SUBPROJECT BUDGET AMOUNT: $822,000 AMOUNT SPENT: $820,251 AMOUNT REMAINING: $1,748 Sound bite of Subproject Outcomes and Results This project predicted invasion risk, assessed ecological impacts, evaluated control efficacy, and investigated factors limiting post-control recovery of native aquatic plants. This was applied to starry stonewort, Eurasian watermilfoil, and curlyleaf pondweed. This will refine approaches for invasion prevention, reduce populations of established AIS, and restore native species. Overall Subproject Outcome and Results Aquatic invasive plants can lower native plant diversity, reduce habitat quality for fish and other animals, and interfere with recreation. To protect Minnesota’s water resources, steps need to be taken to prevent new invasions, control existing populations, and support recovery of native biodiversity. These efforts require sound, science-based guidance. To provide such support, we conducted research to predict invasion risk, assess ecological impacts, evaluate control efficacy, and investigate factors limiting post-control recovery of native aquatic plants. This work was applied to three target species at different stages of invasion: (1) Nitellopsis obtusa (starry stonewort), first found in Minnesota in 2015 and now known in 14 lakes; (2) Myriophyllum spicatum (Eurasian watermilfoil), found in 1987 and established in >300 lakes; and (3) Potamogeton crispus (curly-leaf pondweed), here for >100 years and in >750 lakes. For starry stonewort, we developed models to predict risk of further spread and prioritize search locations for statewide volunteer search efforts, experiments to determine how long starry stonewort remains can survive out of water (i.e., remain transportable by boaters), and field and lab-based control experiments to guide management. For Eurasian watermilfoil and curly-leaf pondweed, we investigated relationships with native plant biodiversity, finding that they displace native species, an effect compounded by lower water clarity, and contribute to “biotic homogenization”—loss of ecological distinctiveness. We are investigating how to better control these invasive species and foster recovery of native vegetation by synthesizing thousands of aquatic plant surveys and management records collected in Minnesota and by conducting in-lake removal and restoration experiments. This work will continue under a follow-up project (MAISRC Subproject 8.2: Impacts of invader removal on native vegetation recovery). Our findings help Minnesotans by highlighting practices needed to protect lake ecosystems and refining approaches for preventing invasions, reducing populations of established AIS, and restoring native species. Subproject Results Use and Dissemination Information from this project has been disseminated through 10 peer-reviewed journal articles, 30 invited talks, 20 contributed presentations, 45 media stories, and resources published on the MAISRC website. Fully published articles (7 of the 10) are included as attachments. Project findings are being used to guide AIS spread prevention and management efforts involving the Minnesota Department of Natural Resources, lake associations, and other stakeholders. This project has also contributed significantly to MAISRC Subproject 10 (“Citizen Science and Professional Training Programs to Support AIS Response”). - Page 2 of 2 - Environment and Natural Resources Trust Fund (ENRTF) M.L. 2013 Aquatic Invasive Species Research Center Sub-Project Work Plan Final Report Date of Report: August 9, 2019 Final Report Date of Work Plan Approval: August 13, 2015 Sub-Project Phase 1 Completion Date: June 30, 2019 Project Completion Date: June 30, 2019 SUB-PROJECT TITLE: Aquatic Invasive Species Research Center Sub-Project 8: Risk assessment, control, and restoration research on aquatic invasive plant species Sub-Project Manager: Daniel J. Larkin Organization: University of Minnesota – Minnesota Aquatic Invasive Species Research Center Mailing Address: 135E Skok Hall, 2003 Upper Buford Circle City/State/Zip Code: St. Paul, MN 55108 Telephone Number: (612) 625-6350 Email Address: [email protected] Web Address: http://larkinlab.cfans.umn.edu/ Location: Statewide Total ENRTF Sub-Project Budget: ENRTF Sub-Project Appropriation: $ 822,000 Amount Spent: $ 820,251 Balance: $ 1,748 Legal Citation: M.L. 2013, Chp. 52, Sec. 2, Subd. 06a Appropriation Language: $4,350,000 the first year and $4,350,000 the second year are from the trust fund to the Board of Regents of the University of Minnesota to develop and support an aquatic invasive species (AIS) research center at the University of Minnesota that will develop new techniques to control aquatic invasive species including Asian carp, zebra mussels, and plant species. This appropriation is available until June 30, 2019, by which time the project must be completed and final products delivered. I. SUB-PROJECT TITLE: Implementing findings: An applied ecologist position and program II. SUB-PROJECT STATEMENT: Aquatic invasive plants are a major threat to Minnesota’s lakes, rivers, and wetlands. AIS plants can grow densely and form surface mats, reducing space and light available to other plant species. This can lower native plant diversity, reduce habitat quality for fish and other animals, and change the way lakes function. Aggressive growth of AIS plants also interferes with boating, recreation, and other human uses. AIS plants can thus harm biodiversity, habitat quality, and human activity. Despite strong interest and investment in preventing new invasions, controlling existing infestations, and supporting the recovery of impacted waterbodies, there are still key gaps in scientific knowledge needed to support effective management. To help address these gaps, this subproject will involve applied research on four high-priority aquatic plant species that are invasive or potentially invasive in Minnesota lakes. These species are at different stages of invasion in Minnesota. Because of this, management priorities and associated research needs differ, from evaluating risk of future invasion and spread, to improving the toolkit available for control, to identifying strategies for aiding recovery of lakes affected by AIS: (1) Nitellopsis obtusa (starry stonewort) is a charophyte (green alga) that is a new invader in Minnesota, having been found in Lake Koronis (Stearns Co.) in summer 2015. Starry stonewort is native to Europe and Asia. It appears to be spreading rapidly in northern-tier lakes, after first being found in the St. Lawrence River in 1978. We will assess risk of further spread of starry stonewort in Minnesota based on climate and environmental factors and by testing how long starry stonewort can remain viable out of water—mimicking potential movement by boaters. We will also test methods for controlling starry stonewort, which has proven difficult and on which there has been almost no scientific research. For now, herbicides/algaecides are the most promising tool for controlling starry stonewort. To ensure that control efforts are as effective as possible while minimizing harm to native species, we will conduct laboratory experiments to test the efficacy and selectivity of different herbicides. This information is urgently needed during this window of opportunity to minimize impacts of starry stonewort to Minnesota lakes. (2) Myriophyllum spicatum (Eurasian watermilfoil) is native to Europe and Asia, was first found in Minnesota in 1987, and now occurs in 322 Minnesota lakes in 40 counties. (3) Potamogeton crispus (curly-leaf pondweed) is native to Europe, Asia, Africa, and Australia; has been in Minnesota since at least the early 1900s; and is now in 750 Minnesota lakes in 70 counties. Eurasian watermilfoil and curly-leaf pondweed have been a focus of management and research in Minnesota for decades. But there are still limits in our ability to effectively control these species and, following treatment, to support recovery of native plant species. We will analyze existing datasets, perform new field work, and develop a citizen-science monitoring program to improve understanding of factors that drive invasion of these species and influence the effectiveness of management efforts. Eurasian watermilfoil and curly-leaf pondweed are not new to Minnesota, but ≥ 94% of our lakes do not contain these species. Improved ability to manage these species and contain further impacts is needed. An undergraduate, graduate student, and postdoctoral researcher will be trained under this subproject. Findings will be disseminated through peer-reviewed publications, presentations, and outreach and extension programming for agency staff, lake service providers, lake associations, and other stakeholders. III. SUB-PROJECT STATUS UPDATES: Sub-Project Status as of May 5, 2016: Dr. Larkin’s full research proposal has been peer reviewed through the Center process, revisions were made, and its workplan and budget approved by