Studying Algae Down to the Molecule

Scientists use a variety of technologies to study harmful algal blooms.

Researchers work in the genetics laboratory
Scientists isolate DNA from seawater samples.

How do researchers monitor microscopic algae in the ocean? The process starts with collecting samples from the field – also known as the Gulf of Mexico. Scientists from the molecular ecology and taxonomy group venture out on vessels, sometimes for days at a time, collecting seawater samples to bring back to the lab for analysis.

Back in the lab, the team first uses light microscopes to identify and count species that form red tides, also called harmful algal blooms (HABs). These blooms occur when microscopic algae multiply to higher-than-normal concentrations. Some toxic species look similar to nontoxic species, and electron microscopes can be used to amplify fine-scale differences in cells to help provide a more definitive identification. However, for certain species, even electron microscopy may not be helpful. In those cases, sensitive genetic tools may provide additional resolution.

In the genetics lab, scientists extract DNA from the algae cells that were collected in the field. They then use the information provided by the microscopists to decide which genetic tool to use to best identify the algae. One of the exciting parts of this work is tailoring the tool that will be used to the question at hand. Certain tools like next-generation sequencing allow them to focus on a whole community, whereas other tools are better for targeting one toxic species. These molecular techniques help facilitate HAB monitoring and event response, and help identify new species of microscopic algae.

Scientists are always working on developing new tools to identify red tide. Currently, they are testing a few different DNA fingerprinting approaches, which are used for species identification and follow a series of steps. First, a variable region of DNA is amplified from cells. Then, this DNA is labeled with fluorescent tags. The size of the DNA region is species-specific (ideally), and is carefully measured using specialized instrumentation. With the help of these technologies, scientists can target key members of an algae community to better understand how they interact within their environments. Some of the challenges in this work are associated with the seemingly infinite amount of data available today: new organisms are identified every day and genetic databases continue to grow at an exponential rate.

 



FWC Facts:
Groupers are very slow-growing fish, taking anywhere from 4-8 years to reach sexual maturity.

Learn More at AskFWC