More than 99% of California’s sunflower sea stars vanished, now scientists have found a mysterious colony that could help revive dying kelp forests

A decade ago, more than 99% of sunflower sea stars vanished from the depths of the ocean. Now, the discovery of a long-lost colony of these organisms is offering new hope for the region's kelp forests.Sunflower sea stars, known as Pycnopodia helianthoides, may look like an aesthetic and purely decorative feature on the ocean floor, but they are ferocious predators. As adults, they can grow up to 24 arms, span three feet wide, and move three feet per minute. They are superlative, and alien, one of the largest and arguably most ravenous sea stars in the world.They dominated much of the ocean floor until the end of 2013, when a colossal marine heatwave swept over the northeast Pacific just as a mysterious underwater epidemic began causing them to die off en masse. A deadly ailment pocked the starfish bodies with lesions and then dissolved into their flesh. It affected roughly 20 species and killed a whopping 57.5 billion sea stars. Over the past century, these large ribbons of golden-brown seaweed had already dwindled in some stretches of the coast, due to the warming ocean conditions.A damaged ecosystemWithout the presence of a primary predator, an excess of purple sea urchins insati...