Why the phenomenon occurs in Florida’s waterways is a question asked by researchers at Nova Southeastern University’s (NSU) Halmos College of Arts and Sciences, which has studied algae blooms since 2019.

“Once we understand what makes these blooms occur, we can work to determine how to not only deal with them when they do, but what steps can be taken to help avoid them in the first place,” said Jose Lopez, Ph.d., an NSU research scientist and principal investigator on this project.

Harmful algae blooms (HABs) can choke off the life in the waterways where they occur, posing a threat to humans on land because when photosynthetic bacteria die off, they can release toxins.

The Molecular Microbiology and Genomics (MMG) Laboratory at NSU’s Guy Harvey Oceanographic Center has been studying HAB microbial communities in Lake Okeechobee to better understand their origins and management.

Along with Lopez, the research was conducted by Lauren Krausfeldt, Ph.D., who joined the NSU lab as a postdoctoral research scientist.

Krausfeldt applied the latest molecular genomics methods to the HAB problem. The primary findings of this work are still being fully analyzed, but include:

• There are many cyanobacterial species in the community, not just the one species, that may be causing the bloom.
• Therefore, there are dynamics between community members that should be understood to regulate how a bloom occurs.
• Bacterial viruses (phage) may also be regulating the community and bloom.
• However, the bloom bacteria, Microcystis, has CRISPR genes that can defend against the phages and give them advantage and allow them to bloom.
• A metagenomics approach has mainly revealed these discoveries, because it does not rely on directly growing live cells. Function and roles can be inferred by reading DNA and specific genes.

“The project has been highly collaborative, as we have worked with various scientists and students from the U.S. Geological Survey and Florida Gulf Coast University, and we are seeing the fruits of our work now,” Lopez said.

Lopez said that the goal is to better understand the dynamics of microbial interactions and which factors may create imbalances, to help alleviate HABs on freshwater ecosystems.

The full article is available online in science.org.