Water Resources Research Act Program

Details for Project ID 2012OR127G

Biological drivers of freshwater cyanobacterial harmful algal bloom extremes assessed via next-generation DNA sequencing technology

Institute: Oregon
USGS Grant Number: G12AP20157
Year Established: 2012 Start Date: 2012-09-01 End Date: 2015-08-30
Total Federal Funds: $243,835 Total Non-Federal Funds: $246,791

Principal Investigators: Theo Dreher

Abstract: Cyanobacterial harmful algal blooms (CHABs) are often associated with toxins and/or taste-and-odor compounds that degrade the quality of public freshwater resources. Extreme hydrometerological events, especially those that result in increased temperatures and decreased water flow, are likely to contribute to increases in CHABs. At present, our understanding of the drivers of cyanobacterial population dynamics is insufficient to accurately predict CHAB events. The proposed study addresses some of the major remaining information gaps in understanding the influences on CHAB populations by using high-throughput pyrosequencing to genetically identify and catalog the cyanobacteria and other bacteria present in three CHAB-affected drinking water reservoirs in Kansas, Texas and Oregon. Two of these lakes are the subjects of long-term USGS studies, which are analyzing water samples year-round for a comprehensive set of physical, chemical and phycological water quality parameters. This study will merge acquired genetic data with those parameters, assembling an exceptionally broad dataset that will be analyzed by regression and multivariate analysis to identify the factors contributing to CHAB emergence, persistence and decline. The genetic analyses of this study will (1) reveal genus/species/strain changes in the cyanobacterial population structure over time; (2) identify the producers of cyanotoxins (microcystin and anatoxin-a) and the taste-and-odor compound geosmin; and (3) identify the population structure of bacteria, including those specifically associated with cyanobacterial colonies, which may influence CHABs by serving as competitors, synergistic mutualists or predators. Exploratory studies will (1) investigate the value of remote (satellite) sensing in providing an integrated estimate of CHAB relative biomass, and (2) the influence of cyanophages on CHAB decline. This study will provide valuable comparative data from three latitudinally and climatically distinct sites and will provide an exceptionally comprehensive dataset that will help move us towards successfully employing mathematical models for bloom event prediction.