The Center's Research Projects

Blooms in Lake Erie have been occurring sporadically for decades, and have now become a regular occurrence and climate change increases the likelihood for more expansive blooms, exposing larger populations to water-borne toxins. While the growth and toxicity of cyanobacteria in Lake Erie has been studied for years, it is only recently that the tools of systems biology (combining ecology, molecular biology and environmental chemistry with limnetic techniques) have been brought to bear on this issue. The objective of this project is to determine the factors that contribute to biomass and toxin production by the cyanobacteria-dominated microbial communities of the eutrophic lower Great Lakes. The physiology and success of the cyanotoxin producers Microcystis and Planktothrix will be tested to ascertain the contributions of climate and anthropogenic drivers to their success. The goals of this study are to develop the information necessary to determine the environmental cues promote or constrain the proliferation (i.e., growth and biomass accumulation) of cHAB species in mixed populations. Our overarching aim in this project is to address the extent to which N availability and temperature  play in the development, toxigenicity and persistence of cHAB taxa in Lake Erie and other bloom-affected freshwaters.

We hypothesize that temperature and N bioavailability are important drivers in yielding the specific composition of cHABs, and thus the effects of variations in N loadings and cycling rates can be differentiated from the effects of climate change.

Microcystis and other cyanobacteria commonly found in cyanobacterial harmful algal blooms (cHABs) harbor numerous gene clusters that encode the biosynthesis of diverse and unknown natural products. This project will test the hypothesis that these gene clusters are responsible for production of variety of unknown toxins and bioactive compounds that threaten human and environmental health and/or could serve as sources of new medicines, yet they remain invisible to current methods commonly used to assess water quality or develop new drugs. The goal is to identify novel toxins and their specific genetic pathways for biosynthesis and regulation through the study of both pure cultures and consortia of uncultured microorganisms. Genomes will be assembled from metagenomes and from representative cultures of dominant bloom-forming cyanobacterial species. High-throughput bioinformatic mining of genomes and metagenomes will identify and prioritize targets for manual curation and structure prediction. In parallel to these gene-based studies, analysis of cultures and field samples will be analyzed to characterize their metabolites, bioactivity, and potential biological targets relating to human disease. Taken together, results on the genetic/biochemical novelty and abundance and expression of genes in Lake Erie blooms will be used to identify high-priority gene clusters for further biochemical characterization of their natural products.  This project will be tightly integrated into the broader activities of the center in that it will utilize DNA sequencing and environmental data and provide information on the structure and bioactivity of toxins.

This project directly addresses four research priorities of the Oceans and Human Health program: (1) compare and correlate current observing systems for monitoring ocean and Great Lakes properties including Harmful Algal Blooms, (2) evaluate long-term field application potential of newly developing in situ sensors for monitoring ocean and Great Lakes properties, (3) evaluate real-time, in-water observations of physicochemical properties, as well as the detection of HAB species and toxins, to provide data streams for assimilation by predictive models, (4) develop appropriate and efficient monitoring strategies for algal toxins (particularly in drinking water) that are protective of public health. The specific aims of the  proposed  project  are  to integrate in situ sensing and sampling technologies with data assimilation strategies to improve forecast accuracy, provide regional stakeholders with advanced warning of cHAB development and toxic events, and evaluate the impacts of climate change on cHABs and internal phosphorus loading in Lake Erie.  We will accomplish these aims by integrating an autonomous, in situ Environmental Sample Processor with Solid Phase Adsorption sampling devices, water quality probes, and field-portable sampling methods to develop a more timely and complete spatio-temporal picture of developing cHAB toxicity and biomass as well as internal phosphorus loading in Lake Erie.