Sea stars are a keystone species, meaning they have a crucial role in keeping the balance in an ecosystem. They help control populations of other species, like mussels for example. Unfortunately for them, and for us, they have been fighting a disease, known as Sea Star Wasting Syndrome (SSWS), since 2013. This disease is supposedly caused by a virus and causes the sea stars to lose their limbs and die. The SSWS virus is said to be already present in sea stars. Several cases of the syndrome have been identified in past years; however, the virus was much more localized in those cases. For an unknown reason, this case has been going on since 2013, ranging from the north-western coast of North America to San Diego, CA, with some reports along the east coast. Scientists have identified that the virus is being set off by some kind of stress. The stress could be temperature dependent (global warming), caused by ocean acidification, predation, or some other type of stress. Some scientists are led to believe that the stress is coming from warmer water temperatures, as many past cases were reportedly due to increased water temperatures. Although warmer water does not cause the virus itself, it can make symptoms worse and cause the disease to occur (1). What is also strange, is that the virus has been found in large amounts in juvenile sea stars, with the juvenile sea stars showing no symptoms (2). Dr. Ian Hewson, a marine microbiologist, states that viruses are host specific, yet the virus has been seen to affect other species of echinoderms, like urchins and brittle stars. Thankfully, viruses have never been known to cause a species to extinct, but the virus will definitely impact how the environment changes with lower populations of sea stars (2). With reports of El Niño occurring since 2013, warmer water temperatures could explain this phenomenon; however, this explanation doesn't make quite sense, as the warmer waters are hitting the coast of California and not all the way up towards Alaska.. Since scientists still aren't sure of the exact cause, we, as conscious citizens, need to impact the ocean as little as possible. Check out our next article (posted next week) on tips to how reduce your carbon footprint, since the disease could be related to increased water temperatures. Even if it's not, the earth could use the help!
If you live in a coastal area and have seen wasting disease, scientists ask that you log your findings at pacificrockyintertidal.org. Sources: 1. "Sickly Starfish: A Q&A with Dr. Chris Mah." Smithsonian Ocean Portal. Web. 27 Sept. 2015.
2. Gokey, Monica. "Virus Suspected in Sea Star Wasting Disease Epidemic." Alaska Public Media. 17 Nov. 2014. Web. 27 Sept. 2015.