Risk assessment, control, and restoration research on aquatic invasive plant species
Project manager: Dan Larkin
Funded by: Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources
Description: Aquatic invasive plants are a major threat to Minnesota’s lakes, rivers, and wetlands. Aquatic invasive plants can form dense mats on the water’s surface, 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. They can also interfere with boating, recreation, and other human uses.
Using applied research on three high-priority aquatic plant species that are invasive or potentially invasive in Minnesota lakes, this research aims to address the need for more guidance and options for controlling these nuisance plants. Species of research include:
- Nitellopsis obtusa (Starry stonewort), a new invasive alga in Minnesota. Researchers will assess the risk of spread through modeling and will also test how long starry stonewort can remain viable out of water to better understand how best to prevent its spread. Additionally, researchers will conduct laboratory experiments to test the efficacy and selectivity of different herbicides and algaecides. This information is urgently needed during this window of opportunity to minimize impacts of starry stonewort to Minnesota lakes.
- Myriophyllum spicatum (Eurasian watermilfoil) and Potamogeton crispus (curly-leaf pondweed), both of which have been in Minnesota for several decades and are now found in hundreds of lakes throughout the state. Although both of these species have been a focus of management and research for several years, there are still limits in our ability to effectively control these species and to support the post-control recovery of native plant species. Researchers 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 that influence the effectiveness of management efforts.
Collectively, this research will aim to create biologically and economically sound solutions to prevent and control these invasive plants and to disseminate scientific information that assists the DNR, watershed districts, lake associations, and citizen groups around the state with management strategies.
Project start date: 2015
Estimated project end date: 2019
As of July 2018, laboratory experiments to test the effectiveness of different algaecides/herbicides on starry stonewort have been initiated. Field sampling is ongoing to evaluate outcomes of starry stonewort control efforts in lakes. Data from statewide treatments of Eurasian watermilfoil and curly-leaf pondweed have been acquired and are currently being synthesized. For both species, researchers have also initiated in-lake removal experiments to determine whether effective control of these AIS is sufficient to support recovery of native aquatic plant communities or whether additional management strategies (e.g., water quality improvement, native plant seed addition) are needed to restore native aquatic vegetation.
Ecological niche modeling has been completed for starry stonewort, using occurrence data from 8 countries, 19 climate variables, and remotely sensed environmental data to characterize the environmental niches occupied by starry stonewort in its native and invaded ranges. Initial findings indicate that starry stonewort has expanded into regions of the U.S. with climate conditions distinct from those found in its native range. Roughly one-third of Minnesota appears to constitute suitable habitat for starry stonewort, as do large portions of the Intermountain West, Great Plains, and Mid-Atlantic — areas with no known occurrences to date. Next, researchers will scale down risk assessment to individual lakes within Minnesota. Lakes identified as high-risk will be recommended for targeted surveillance by the AIS Detectors program.
- New research challenges assumptions about biodiversity-invasibility relationships in lakes (MAISRC newsletter)
- Biology, ecology, and management of starry stonewort (Nitellopsis obtusa; Characeae): A Red-listed Eurasian green alga invasive in North America (Published paper)
- Response of the invasive alga starry stonewort (Nitellopsis obtusa) to control efforts in a Minnesota lake (Published paper)
- Research on fighting starry stonewort yields limited success (MAISRC in the news)
- Environmental filtering and competitive exclusion drive biodiversity‐invasibility relationships in shallow lake plant communities (Published paper)
- U of M study: Plant diversity doesn't protect lakes from invaders (MAISRC in the news)
- Research on starry stonewort treatments informs management efforts (MAISRC newsletter)
- Registration now open for Starry Trek! (MAISRC newsletter)
- Taking on starry stonewort's opening act (MAISRC in the news)
- Minnesota Boaters Urged To Fend Off New Invasive Plant (MAISRC in the news)
- Lake Koronis is test lab in fight against invasive species (MAISRC in the news)
- New research shows algaecide treatments knocked back starry stonewort but failed to kill bulbils (MAISRC Newsletter)
- Aquatic weed, starry stonewort, creeps across US (MAISRC in the news)
- New U of M Research Lab Works to Stop Aquatic Invasive Species (MAISRC in the news)
- Threat of another AIS (MAISRC in the news)
- More questions than answers for starry stonewort in Minnesota (MAISRC in the news)
- Realized niche shift associated with the Eurasian charophyte Nitellopsis obtusa becoming invasive in North America (Published paper)
- New suite of research on aquatic invasive plants kicks off (MAISRC Newsletter)
- Watch the starry stonewort webinar here (Events)
- Predicting the spread of starry stonewort in Minnesota (MAISRC newsletter)
- U of M Adding Research Capacity in Aquatic Invasive Plants Management (press release)