Grantee Research Project Results
2020 Progress Report: A systems approach for understanding, predicting, and managing harmful algal blooms in Midwestern lakes
EPA Grant Number: R839270Title: A systems approach for understanding, predicting, and managing harmful algal blooms in Midwestern lakes
Investigators: Howe, Adina , Ikuma, Kaoru , Swanner, Elizabeth , Choi, Jinlyung , Lee, Jaejin
Current Investigators: Howe, Adina , Ikuma, Kaoru , Swanner, Elizabeth , Lee, Jaejin
Institution: Iowa State University
EPA Project Officer: Packard, Benjamin H
Project Period: January 1, 2018 through December 31, 2020 (Extended to December 31, 2021)
Project Period Covered by this Report: January 1, 2020 through December 31,2020
Project Amount: $760,000
RFA: Freshwater Harmful Algal Blooms (2017) RFA Text | Recipients Lists
Research Category: Water , Watersheds , Water Quality
Objective:
Objective of Research: This project explores genetic and environmental factors controlling the occurrence of harmful algal blooms (HABs) in Iowa's lakes. The project will produce tools and databases accessible and useful for state/local decision makers and managers dealing with HABs. This project improves monitoring and predictive tools targeting future cyanotoxin monitoring and mitigation efforts. Resulting research and tools may be applicable in other states.
Progress Summary:
We have conducted an integrated monitoring of HABs, microcystin, and microbiomes from Iowa's recreational waters. As proposed, we have collected two years of datasets and have used these efforts to improve biomarkers for microcystin-producing cyanobacteria, characterize microcystin producing and degrading bacteria, and establish a one-week ahead predictive model for the presence of microcystin toxins. Additionally, in year 3, due to the unique nature of the 2020 sample collection year and the potential impacts of COVID and reduced human impact, we collected samples with the Iowa DNR Beach Monitoring for toxicity gene characterization.
Standard operating procedures now exist for identifying and quantifying phyla-specific qPCR assays for the microcystin synthetase mycA gene resolving this gene in Microcystis, Anabaena, and Plankothrix. These assays are performed on a high throughput microfluidic qPCR platform, enabling hundreds of samples to be tested in under four hours. Measurements of concentrations mcyA genes, microcystin measurements, and water quality measurements have been integrated to develop a Random Forest model that predicts 1-week ahead the range of microcystin concentrations (i.e., over EPA’s guideline (³ 8 mg/L) and below the threshold (< 8 mg/L)). The overall accuracy of the RF model was 94.4% for the training set and 97.2% for the test set. A Classification and Regression Tree (CART) model was also suggested to help the users get better understanding on the rules for decision makings. The overall accuracy of the CART model was 93.8% for the training set and 94.5% for the test set.
We have isolated and enriched a novel and putatively toxigenic strain involved in saxitoxin production. We are currently testing for saxitoxin production and analyzing the genome of this organism. If verified, it would be the first description of saxitoxin production in the genus Nostoc. Additionally, we have isolated and started to characterize various toxin-degrading microbes. Based on these efforts, a strain library of both microcystin-producing cyanobacteria and microcystin-degrading bacteria exists, and we are characterizing their phylogenetic identifies and metabolic activities. Preliminary results indicate that different mechanisms are used to degrade microcystin-LR, despite similarity in mlrA genes. Numerous enrichments were made of 2019 samples, and screened for the presence of genes for microcystin, cylindrospermopsin, anatoxin, and saxitoxin production using PCR. Two enrichments were positive for the sxtI gene.
The taxonomic assessment of multi-wavelength fluorescence for HAB-associated biota is being accomplished through a comparison of 16S rRNA sequencing of cyanobacteria and 18S rRNA sequencing of eukaryotic algae. Data analysis is nearly complete, and a manuscript has been drafted. The outcomes will be a SOP of best practices for data collection, a statistical analysis workflow to supplement the instrument manufacturer’s software in determining this method is accurate for total chlorophyll a and taxonomic determinations in near real-time.
Future Activities:
We will continue integrating our tools with IDNR. The main activities of the next year will be the publication and communication of the predictive HAB model, toxin-degrading and producing isolate characterization, and the fluorescence spectra methods for HAB detection.
Journal Articles:
No journal articles submitted with this report: View all 11 publications for this projectSupplemental Keywords:
Cyanobacteria; mycA gene; model; water quality
Relevant Websites:
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.