http://www.sciencemag.org/news/2019/09/blob-back-new-marine-heat-wave-threatens-pacific

In 2017, a marine heat wave bleached this coral reef in Hawaii’s Hanauma Bay. Now, officials are bracing for a new bleaching event driven by unusually warm ocean waters.

In the fall of 2014, marine ecologist Jennifer Fisher was stunned when jellyfish and tiny crustaceans typically found in warmer waters filled her nets off the coast of Oregon. The odd catch was just one sign of the arrival of a vast patch of warm water that came to be known as “The Blob”—a massive marine heat wave that lasted 3 years and dramatically disrupted ecosystems and fisheries along North America’s Pacific coast.