Think of a hot summer day. Imagine getting a glass of cold water, but no water is coming, or it is brownish with a foul odor. Imagine being a farmer, and your cattle need water but there is only smelly (blue-)green water. Imagine going for a cooling swim, but the lake is closed for recreation. For millions of people, this is not imagination, but a recurring reality caused by toxic cyanobacterial blooms.
Harmful cyanobacterial blooms produce toxins that are a major threat to water quality and human health. Blooms increase with eutrophication and are expected to be amplified by climate change. Yet, we lack a mechanistic understanding on the toxicity of blooms, and their response to the complex interplay of multiple global change factors. Bloom toxicity is determined by a combination of mechanisms acting at different ecological scales, ranging from cyanobacterial biomass accumulation in the ecosystem, to the dominance of toxic species in the community, contribution of toxic genotypes in the population, and the amounts of toxins in cells.
In this project, we will develop a fundamental understanding of bloom toxicity by revealing the combined effects of nutrients, elevated pCO2 and warming at each scale, and integrate these responses using a unique combination of ecological theory, technological advances, and methodological innovations. Specifically, we will use first principles to scale from cellular traits, like carbon and nutrient acquisition, cellular toxin synthesis and growth rates, to population and community dynamics.