Proliferations of toxic cyanobacteria in flowing waters are emergent environmental concern. We currently build knowledge about their environmental triggers and adverse effect on aquatic ecosystems and human health. In our lab we study the following questions:
• Which species of cyanobacteria produce neurotoxins in streams and rivers?
• What is the composition and dynamics of benthic harmful algal communities?
• What are the environmental preferences and ranges of toxigenic cyanobacterial species?
• What ecological factors trigger cyanobacterial biomass and toxin production?
• What is the environmental harm of cyanotoxins?
2023-2027 NSF URoL:EN #2222322. Understanding the rule of life facilitating the proliferation of toxic cyanobacterial benthic mats in flowing freshwaters
2023-2025 Interstate Commission on the Potomac River Basin. Investigation of Drivers of Harmful Algal Blooms on the Shenandoah River, Virginia.
2023-2024 4-VA@Mason Collaborative Research Grants. Using taxonomic, pigment and molecular analysis to characterize algal blooms in the Shenandoah River
2024-2025 4-VA@Mason Collaborative Research Grants. Integrative characterization of the anatoxin-a-producing benthic cyanobacterial genus Microcoleus in the Shenandoah River
Algae are powerful indicators of stream ecosystem health. In our lab we study algae diversity and ecology aiming to:
• Provide high-quality species level data for stream bioassessment and algal indices of biotic integrity.
• Refine local algal floras by describing new to science species and clarifying species ranges and optima.
• Elucidate the effect of climate change on stream algae and their strategies to cope with desiccation stress.
2024-2025 SWAMP of the California State Water Resource Control Board
We analyze the species composition, density and biovolume of phytoplankton to answer questions about the ecological conditions of aquatic ecosystems, and potential signs of eutrophication and harmful algal and cyanobacterial blooms.
2023-2024 Fairfax County. An Ecological Study of Gunston Cove: 2022-23
2023-2024 Fairfax County. Lake Phytoplankton Analysis
We continue our K-12 environmental education started in California (see website below) with focus on protecting freshwater resources to help build the new generation of aquatic explorers and environmental leaders.
Aquatic Explorers
Laboratory manipulation experiments with unialgal strains of cyanobacteria and eukaryotic algae isolated from local aquatic habitats are great tool to answer many research questions and test variety of hypothesis. For instance, we can learn about species tolerances to environmental conditions, such as light, temperature, nutrients, pollutants, desiccation stress, etc. When coupled with cytological, transcriptomic or toxin analyses these experiments tell us about the cellular acclimation mechanisms of tested algae.
2023-2027 NSF URoL:EN #2222322. Understanding the rule of life facilitating the proliferation of toxic cyanobacterial benthic mats in flowing freshwaters
Some algae are very sensitive and challenging to grow in the lab, but we have been successful in isolating green algae and cyanobacteria from streams in California and Virginia. Below, you will see five glass tubes with algal cultures. Notice the different colors of the algal strains and the oxygen bubbles the algal photosynthesis produces.
(1) Palmella (green alga) green cells;
(2) Palmella (green alga) red cells which contain the additional red pigment carotenoid, which acts as sunscreen and protects the cell from UV light;
(3) Microcoleus (cyanobacterium) filaments – some species may produce neurotoxin anatoxin-a responsible for dog fatalities;
(4) Haematococcus (green alga) red cells which contain bloody red pigment astaxanthin, a powerful antioxidant carotenoid;
(5) Anabaena (cyanobacterium) filaments with akinetes andheterocytes – some species may produce neurotoxin anatoxin-a.
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