Killer Algae's 'Fingerprints' Wrap Up The Case

Just like plants on land, phytoplankton is an important source of nutrition for other organisms and is responsible for the major part of the global primary production. Sometimes the phytoplankton toxins can be so potent that they can cause severe illness and even death in humans. Authorities, administrators, and researchers are interested in methods that can rapidly locate harmful phytoplankton species. Since phytoplankton species are tiny, 1-100 thousandths of a mm, and several of them look similar, it is difficult to distinguish various species in a microscope. One way to get around this is to analyze their DNA.

“DNA is species-specific and is similar to a fingerprint, which makes it possible to distinguish between different species,” says Holly A. Bowers.

One way to analyze DNA is through real-time PCR, where you dye the DNA of a single species with a fluorescent preparation. The light can then be measured, and more light means more cells of the species there are in the water sample.

Holly A. Bowers’ doctoral thesis describes how real-time PCR has been adapted to quickly and reliably identify and estimate a number of harmful phytoplankton species quantities present in the water. The DNA tests that Holly A. Bowers developed for her thesis are now used in several places around the world, especially in the Chesapeake Bay, Maryland, U.S. The findings of the DNA tests have helped researchers, authorities, and administrators to understand the spread of harmful phytoplankton species.

The part of the doctoral work carried out in the U.S. mainly focused on identifying harmful species as part of a state-sponsored monitoring program. In Kalmar, Sweden, the DNA tests were used to study the feeding behavior of a phytoplankton species responsible for fish kills in coastal waters around the world, including the Baltic outside Kalmar.