Four years ago, along the West coast of the United States, the starfish in the area began suffering from a disease that eventually became known as Sea Star Wasting Syndrome. It would seem that the starfish have started to make a comeback. The evidence is simply in the numbers. Marine biologists have begun to find starfish once again in the tide pools around southern California, where there haven’t been any for years following the outbreak of the disease.
The Sea Star Wasting Syndrome affected starfish from Canada all the way through southern California. The effects of the disease were pretty extreme. Seas stars would lose limbs, and in some cases, they would dissolve completely into a puddle of goopy white material. There are approximately 2,000 species of starfish in the world’s oceans, and the disease on the West coast struck at least 10 of them. The University of Santa Cruz has been tracking the disease and its ecological effects, and so far the exact cause is unknown.
This disease isn’t the first of its kind. On the East coast of America, a similar disease broke out and was determined to be a virus. This virus is a fairly common event after a period of overpopulation among starfish species. Scientists couldn’t find that kind of confirmed root cause on the West coast, however. The only theory that’s been developed is that the water off the West coast has been warmer than usual, and that warm water could potentially allow deadly bacteria to develop and thrive. An outbreak of Sea Star Wasting Syndrome also occurred in 1983 and again in 1997.
While the actual cause of the disease is unknown, the effects can’t be denied. The affected starfish would develop lesions that would multiply at a quick rate. Following the lesions, limbs would begin to fall off until, eventually, the starfish would completely dissolve. The whole process can happen in as little as just a few days or weeks.
Some regions saw mortality rates as high as 95 percent. As mentioned above, at least ten starfish species were affected, but the most heavily hit was a species called Pisaster ochraceus, more commonly known as the ochre sea star.
A threatened species is never a good thing for an ecosystem, so it’s reassuring to know that the starfish appear to be making a comeback. Science and future data will likely shed more light on how impactful the disease was in the coming months.