Water Resources Research Act Program

Details for Project ID 2020CT030B

A Quantitative Assessment of the Spatiotemporal Dynamics of Algae, Cyanobacteria, Cyanotoxins, and Water Quality in Lower Bolton Lake

Institute: Connecticut
Year Established: 2020 Start Date: 2020-02-28 End Date: 2021-02-26
Total Federal Funds: $25,000 Total Non-Federal Funds: $50,002

Principal Investigators: Christopher R. Perkins

Abstract: Cyanobacterial blooms are a major ecological and human-health problem in all 50 states, with considerable economic consequences. Blooms of cyanobacteria and algae arise because of underlying physicochemical factors associated with eutrophication of surface waters. In addition to causing anoxic conditions that negatively affect biota, cyanobacteria release toxins, including microcystins and anatoxins, which induce gastroenteritis, liver diseases, allergic reactions, and irritation in humans. The first recorded cyanobacterial bloom in the Connecticut occurred during the summer of 2012, in Lower Bolton Lake. As a result, the State instituted a monitoring program to conduct a preliminary assessment of the physicochemical or biotic factors that lead to cyanobacterial blooms and cyanotoxin production at several freshwater beaches and lakes. Until 2017, the occasional freshwater beach closures were based on visual assessment and algal or cyanobacterial densities, as cyanotoxin concentrations were well below state and federal limits. The established pattern changed in 2017, with marked differences in the concentration and profile of cyanotoxins. More specifically, 1/3 of the samples collected from Connecticut’s freshwater beaches exceeded State guidance for total cyanotoxins, and two types of cyanotoxins were detected for the first time in Connecticut. Recent increases in cyanotoxin concentrations, shifts in cyanotoxin profiles, and uncertainty concerning the physiochemical characteristics that drive bloom formation and toxin production, demonstrate a compelling need to expand and enhance existing monitoring. We propose a study of algal and cyanobacterial populations and cyanotoxin production that is coupled explicitly with a comprehensive assessment of water quality at Lower Bolton Lake, a waterbody known to be regularly affected by cyanobacterial blooms. More specifically, we will collect and analyze water samples and profiles from 3 depths at 5 locations within each of 3 spatial zones, and will do so on a bi-weekly basis from mid-June through October. Using a suite of multivariate analyses (e.g., multiple regression, hierarchical and variation partitioning, and time-series analysis) that control for the correlation structure of predictor characteristics, we will quantify the extent to which variation in water quality characteristics is linked to variation in algal and cyanobacterial population densities, ultimately leading to variation in cyanotoxin profiles. The proposed work will enhance predictive understanding of the spatiotemporal dynamics and drivers of cyanobacterial blooms in economically and recreationally valuable lakes, and serve as a prototype for development of monitoring programs that can be implemented elsewhere in the region. The project leverages the training of undergraduate students in multidisciplinary skills that combine approaches and tools from algal and bacterial biology, ecology, chemistry, and statistics. We will incorporate these perspectives and methodologies into internship experiences or independent study projects that will lead to production of student-initiated presentations and publications. Although this project is designed to be completed within a single funding cycle, we anticipate seeking a second year of funding. This additional year will enhance the ability to capture bloom events and toxin production, as well as the physical, chemical, and biological characteristics that precede and accompany them.