The microscopic alga Karenia brevis causes harmful algal blooms (red tides) in the Gulf of Mexico. By studying the processes regulating the life cycle of K. brevis, we developed biomarkers to identify actively growing blooms and signs of blooms in demise. Accurate knowledge of the status of a K. brevis bloom will allow coastal managers to better forecast the impacts of harmful algal blooms.
Why We Care
The occurrence of K. brevis blooms in the northern Gulf of Mexico in the past decade has surpassed previous records, with blooms often persisting in coastal waters for many months. These coastal blooms cause human neurotoxic shellfish poisoning, respiratory irritation when toxin is aerosolized, and extensive fish and marine mammal kills. The impacts on public health, commercial shellfisheries, and tourism cause economic losses in the tens of millions per year. There is currently no simple method to determine the growth phase of a bloom that can be used by managers to better forecast the longevity and impacts of Florida red tides.
What We Are Doing
We are developing fluorescent biomarkers to measure the percentage of cells actively growing in a bloom patch and the percentage showing signs of stress or cell death. For the growth biomarker, we are using expression of the cell cycle protein “PCNA,” which is expressed only in actively dividing cells. To identify cells undergoing cellular stress, we are using a fluorescent tag that identifies cells with high loads of harmful reactive oxygen species inside. To identify cells actively undergoing programmed cell death, we are using an assay called “TUNEL,” which identifies cells suffering from damaged DNA. Using fluorescence detection, these biomarkers can be adapted to flow cytometry, which allows for ship-board application and automated quantification of samples from a bloom patch.
Once our biomarkers are validated in the laboratory, we will test the methods on natural bloom patches in the Gulf of Mexico in collaboration with the Florida Red Tide Monitoring Program. We will then transfer the methodology to regulators responsible for red tide monitoring and management.