Blue-green algae, like a lot of other things in nature, is part of what researcher Kaitlin Reinl calls "a happy, healthy ecosystem."
Too much of it, though, and it's a problem. Algal blooms consuming oxygen as they die and decompose can create dead zones - areas in water with little or no oxygen - where aquatic life cannot survive. And the same toxins that can make people sick or even kill their dogs can kill fish, too.
So the more we know about blue-green algae - in particular the link between major algal blooms and extreme weather events - the easier it will be to keep it in balance with the rest of the ecosystem.