No one quite knows what happened in the tropical aquarium of a German zoo two decades ago, but according to biologists, experiments with a tropical seaweed unleashed a hybrid algae which is now decimating marine life in the Mediterranean. It was in the late 1980s that Alexandre Meinesz, a professor of biology at France's University of Nice-Sophia Antipolis on the Mediterranean coast, first detected the spread of a new species of algae along the French coastline. Horizon follows Meinesz on a scientific detective story as he attempts to unravel the source of this alien algae, alert the authorities to the danger and find a solution.
