Harmful cyanobacterial bloom events occur when water conditions encourage the growth of algal species that can produce toxins. Recently, the diversity of algal species within blooms in the Sacramento-San Juan Delta has increased, as has the abundance of algae. Scientists don’t yet know what is causing the expanded blooms or how the increased diversity will impact the spread of toxins.
Researchers will collect samples of cyanobacteria and co-occurring bacteria from blooms in the central and south Delta to assemble their genomes using a new technique called genome-resolved metagenomics. This data will reveal which algae species — and which gene clusters specifically—are responsible for the production of toxins, among other biological functions.
The analysis of which genes control toxin production — as well as nutrient uptake, salinity tolerance and other physiological processes — will directly address several high priority Delta Science Actions in the 2022-2026 Science Action Agenda that focus on toxic bloom events. Ultimately, the study will inform public health monitoring and allow the development of toxic algal bloom forecasts that take into account the increased diversity of cyanobacteria recently observed in the Delta’s blooms.