Going, going, gone? What’s happening to the Sunflower sea star

Something strange and cataclysmic is happening along the Pacific Coast of the United States. It’s a bit of a mystery with dead bodies everywhere…5.75 BILLION dead bodies!!!! What is responsible for the death of the sunflower sea stars? It would seem that the answer isn’t straight forward. But these brightly colored (orange, purple, brown and yellow) sea stars, the largest in the world (up to 3 ft across) are missing from between 90 percent and nearly 100 percent of the their range south of Seattle. They once could be found from Alaska to Mexico.

The sunflower sea stars have vanished along 2000 miles of coast. Warming ocean temperatures aren’t the sole cause of their disappearance because even at depths down to 3000 feet the sea stars have disappeared. The International Union for the Conservation of Nature has listed the sunflower sea star as critically endangered. Not just bad news for the sea star but for all the other organisms that rely on the existence of this ocean predator. Sea stars prey on creatures like sea urchins that eat kelp. Without the sea stars the urchins grow in such numbers that kelp forests are decimated. Without the kelp, animals that depend on kelp for protection and food like sea otters, seals, and fish suffer too.

Changes in ocean temperature, acidification, and other factors due to global warming stress the sea stars and most likely make them more susceptible to sea star wilting disease (photo right). While scientists don’t know the origin of the disease, attempts are underway to breed sunflower sea stars so that some day populations may be restored (video below).