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Images: A Fatal Attraction for Harmful Algae

CLEANING UP WITH CLAY—Scientist Mike Henry of the Mote Marine Laboratory sprays clay slurries into Florida’s Sarasota Bay while WHOI Postdoctoral Investigator Mario Sengco and colleagues in the other boat track the dispersal of the plume with water sampling devices. The researchers are investigating the use of natural clays as a potential tool to mitigate harmful algal blooms, or “red tides.” (Jim Cutter, Mote Marine Laboratory.)

LITTLE PLANT, BIG PROBLEM—Harmful algal blooms are caused by species of tiny plants—phytoplankton—that produce potent chemical toxins. Fueled by periodic abundances of nutrients in the ocean, these algae multiply and proliferate until they can cover tens to hundreds of miles of coastal ocean. (Don Anderson, WHOI.)

ON GUARD AGAINST ALGAE—In South Korea, fish farmers spread clay to ward off harmful algae that could devastate the crop in their pens. The results can be striking. After South Koreans began clay treatments, fishery losses fell from $100 million to $1 million per year. (National Fisheries Research and Development Institute, South Korea.)

Removing harmful algal blooms with clay. (Illustration by Jack Cook, WHOI Graphic Services)

TEXAS TWO-STEP—In an experiment in Corpus Christi, Texas, WHOI scientist Mario Sengco pumped algae-rich water into tanks and treated them with clay. Within hours, the sinking clay removed more than 70 percent of the algae. (Aishao Li.)