Water Resources Research Act Program

Details for Project ID 2015CT292B

Mitigating Eurasian watermilfoil invasion success and ecosystem impact using native herbivores

Institute: Connecticut
Year Established: 2015 Start Date: 2015-03-01 End Date: 2016-02-28
Total Federal Funds: $4,025 Total Non-Federal Funds: $9,818

Principal Investigators: LaTina Steele

Project Summary: Eurasian watermilfoil (Myriophyllum spicatum) is an invasive submerged aquatic plant that impacts lakes nationwide, including those in Connecticut. It has become a nuisance species in many Connecticut lakes, leading to costly and often ecologically harmful eradication efforts. Unfortunately, we have only limited understanding of the factors contributing to successful invasion by Eurasian watermilfoil. Understanding the mechanisms leading to successful M. spicatum invasion is a critical first step for effective management. We propose a project that will investigate the role of chemical deterrents in mediating milfoil invasions, coupled with an exploration of native herbivores that tolerate these deterrents and might serve to control invasive milfoil populations. To elucidate the factors contributing to milfoil’s invasion success, we will first characterize the chemical deterrents produced by M. spicatum, specifically focusing on previously unexamined diurnal patterns of chemical deterrent production, as well as diurnal herbivory patterns. Furthermore, we will experimentally determine which native herbivores consume M. spicatum and which combinations of herbivores are most effective in reducing standing milfoil biomass. Moreover, we will thoroughly characterize the community within a milfoil-impacted lake and use field and laboratory experiments to examine community characteristics that may contribute to milfoil invasion (e.g., native plant, algal, herbivore, and predator diversity, proportion of chemically defended plants). Lastly, to gain a more complete understanding of milfoil’s impacts on local ecosystems, we will conduct field experiments to document the effects of predator presence on milfoil consumption and herbivore community composition and diversity. Data generated during this project will allow for better identification of lakes that are most at risk for milfoil invasion, as well as pointing to management strategies to mitigate established milfoil populations.