A recent study funded by NOAA’s National Centers for Coastal Ocean Science has uncovered evidence that naturally co-occurring bacterial species may play a crucial role in either sustaining or inhibiting Karenia brevis blooms, more commonly known as red tide (a type of harmful algal bloom). The researchers’ findings identify the importance of understanding the microbiome associated with K. brevis, and may lead to better predictions of red tide events as well as more effective and safe control solutions for Florida’s coastal communities.
K. brevis blooms often produce potent toxins that can kill marine life and cause serious illness in humans who consume contaminated shellfish. Airborne toxins from breaking waves can also pose health risks to beachgoers, particularly those with respiratory conditions. This study seeks to better understand the complex factors that influence the growth and decline of red tide blooms along Florida’s Gulf Coast.
Using these techniques, the research team identified two types of bacterial strains that were algicidal, Croceibacter atlanticus and Pseudoalteromonas spongiae. Conversely, another species, Mameliella alba, was found to provide essential nutrients, such as B-vitamins, that fuel and promote algal growth. These findings highlight the dual role that co-occurring bacteria can play in influencing the growth and physiology of K. brevis blooms.
Understanding the different factors that can contribute to the growth or decline of red tide blooms is essential for advancing our knowledge of bloom ecology and determining factors that cause blooms to end. This study is the first to identify specific marine bacteria that co-occur with K. brevis populations, and identifies their role in critical cell functions and regulating red tide blooms. These findings will benefit harmful algal bloom forecasting efforts and could lead to new natural control methods to mitigate the impacts of these blooms on coastal communities, ecosystems, and economies.
This research was led by the NYU Abu Dhabi Marine Microbiomics Lab as part of a Mote Laboratory-led project funded by the NCCOS Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) program.
This work is authorized by the Harmful Algal Bloom and Hypoxia Research and Control Act (HABHRCA) 33 U.S.C. §§ 4001 et seq.
Citation: Fei, C., Booker, A., Klass, S., Vidyarathna, N. K., Ahn, S. H., Mohamed, A. R., and Amin, S. A. (2025). Friends and foes: symbiotic and algicidal bacterial influence on Karenia brevis blooms. ISME communications, 5(1), ycae164. https://doi.org/10.1093/ismeco/ycae164