A new study by scientists from North Carolina State University and the National Oceanic and Atmospheric Administration (NOAA) published in the March 12, 2013, issue of the open access peer reviewed journal Public Library of Science has found that red tide in the Gulf of Mexico is caused by a food shortage in the species of algae that produce the red tide phenomenon.
The researchers found that the Karenia brevis algae, which cause red tide blooms across the Gulf of Mexico, become two to seven times more toxic when levels of phosphorus are low. Phosphorus is an essential nutrient for algae.
Red tide can produce respiratory ailments in humans and is responsible for economic losses in the fishing industry.
The research gives public health officials a means to predict the occurrence of red tide before the red tide begins by monitoring the level of phosphorus.
The researchers do not suggest a means of adding phosphorus to sea water to prevent red tide but do note that the majority of phosphorus in coastal areas result from fertilizer introduced into the ocean by farming and industry.
Citation: Hardison DR, Sunda WG, Shea D, Litaker RW (2013) Increased Toxicity of Karenia brevis during Phosphate Limited Growth: Ecological and Evolutionary Implications. PLoS ONE 8(3): e58545. doi:10.1371/journal.pone.0058545