Scientists discover genetic basis for how harmful algae blooms become toxic

In a new study, researchers identified a cluster of genes related to the production of domoic acid in microscopic plants, or phytoplankton, called Pseudo-nitzschia.

Dense cells of the harmful algae Pseudo-nitzchia during a bloom off the West Coast of North America. Credit: NOAA

The researchers found that the genes contain the biological directions for how the toxin is made; these genes are "switched on" when Pseudo-nitzschia is producing domoic acid.

By showing how genes for domoic acid production are turned on, the authors suggest a way to connect the ocean conditions that drive algae blooms with the development of toxin production.

Harmful algae blooms often come in the form of "red tides," so called because of the reddish tint they lend ocean waters. The blooms occur when phytoplankton grow rapidly, sometimes producing toxins that can sicken marine mammals and other species.

Harmful algae blooms also pose a threat to human health when the toxins accumulate in seafood. A high-dose exposure to domoic acid can lead to amnesic shellfish poisoning, a potentially fatal condition marked by seizures and short-term memory loss.

Several states have been severely impacted by harmful algae blooms. The largest harmful algae bloom ever recorded happened in the summer of 2015 off the West Coast of North America from Alaska to California, and resulted in the closure of fisheries to protect consumers from potential shellfish poisoning.

Harmful algae blooms are difficult to forecast, scientists have found. The bloom-causing organisms usually have very complex genomes. Knowledge of the genes involved in domoic acid production will allow for better monitoring of algae blooms, scientists say, and aid in identifying the conditions that trigger toxin production.

When phosphate in the ocean is limited and the amount of carbon dioxide increases, Pseudo-nitzschia can make large amounts of domoic acid and become harmful.

Carbon dioxide in the sea is increasing above natural levels. Along with rising ocean temperatures, these conditions lead to more prevalent, more toxic, and longer-lasting blooms and domoic acid production.

Researchers who work on monitoring and forecasting harmful algae blooms say the findings offer an increased understanding of the phenomenon, and will help predict domoic acid events in response to climate change. (National Science Foundation)

YOU MAY ALSO LIKE

Bioengineers create functional 3D brain-like tissue

Bioengineers have created three-dimensional brain-like tissue that functions like and has structural features similar to tissue in the rat brain and that can be kept alive in the lab for more than two months.

Ancient DNA analysis unlocks secrets of Ice Age tribes in the Americas

Scientists have sequenced 15 ancient genomes spanning from Alaska to Patagonia and were able to track the movements of the first humans as they spread across the Americas at “astonishing” speed during the last Ice Age, and also how they interacted with each other in the following millennia.

Brazilian researchers identify microalgae that can provide biofuels

A research project conducted by the Agroenergy division of the Brazilian Agricultural Research Corporation has identified species of microalgae that can be grown in liquid waste from agroindustrial processes to provide renewable raw materials.

Better Not to Show Kids Movies with Guns

Children who watched a PG- (Parental Guidance-) rated movie clip containing guns played with a disabled real gun longer and pulled the trigger more often than children who saw the same movie not containing guns.

Study considers sensory impacts of environmental change on ocean species

Studies reveal that environmental change may lower feeding success in cormorants and other species.

Seven miles deep, the ocean is still a noisy place

For what may be the first time, NOAA and partner scientists eavesdropped on the deepest part of the world’s ocean and instead of finding a sea of silence, discovered a cacophony of sounds both natural and caused by humans.