Algal blooms are growing bigger and more frequent worldwide as ocean temperatures rise and circulation patterns change.
Climate change is likely one cause of the alterations, which favor the growth of phytoplankton, according to a new study published in Nature.
Whether it’s good or bad is a murky question. Algae are an important food source for many marine animals, and large blooms can sometimes be a benefit for ocean ecosystems and fisheries.
But some algal blooms also release toxins into the water and poison the environment. And when blooms die off and begin to decompose, they can reduce the oxygen concentrations in the water, harming the ecosystem.
Because of the potential for both positive and negative outcomes, experts keep a close eye on algal blooms around the world.