From Alaska down to San Diego tens of thousands of Pacific coast starfish are becoming sick and ripping themselves apart. The uncanny disease, dubbed 'sea star wasting syndrome,' causes starfish arms to uncontrollably crawl in opposite directions until the starfish is ripped apart. Nobody knows why.
More than a dozen different starfish species have been exhibiting this malady. Some cases have cropped up on the Eastern seaboard, but the Pacific coast is where the devastating echinoderm epidemic has become most pronounced.
While mottled stars, sun stars, and pink stars have been affected, the hardest hit starfish populations have been those in the purple star and the sunflower star species -- many disappearing in just a matter of weeks, even despite a dense aggregation initially.
The first noticeable signs of the illness are emaciated frames and lesions that develop on the starfish. The starfish then start to twist themselves, especially their arms, into knots. Eventually the arms break off from the starfish, leaving the starfish unable to regenerate their limbs. The starfish then waste away thereafter. And at the extreme end, the limbs rip the starfish enough to have their insides spill out.
Canadian divers first reported seeing these sick starfish back in mid-2013. In a matter of just weeks, the disease spread further south into US waters, so that by early 2014 starfish in Oregon and California started manifesting the same mysterious disease.
The current theory is that a ship carried a pathogen from another part of the world; the implications are that these North American starfish have not developed any immunity to the pathogen. Evidence supporting this theory includes the fact that the areas where starfish manifest this perplexing illness coincide with some major shipping lines.
Scientists are highly concerned about this mysterious disease because starfish are vital predators in the ecosystem, making them a keystone species since they shape the biodiversity of their habitat. Healthy starfish have ravenous appetites, and they tend to consume incredible amounts of food -- such as urchins, sea cucumbers, crabs, oysters, clams, mussels, even other starfish. The absence of starfish means an explosion of urchin and mussel populations, for instance. Thus, the vacuum created in marine habitats by the reduction or depletion of starfish will adversely tip the balance in the ecosystem and lead to far-reaching consequences.
There has been suggestion that this incident is a cycle, citing a similar occurrence in the 1980s with El Nino or the periodic warming of waters as South American currents creep northward. In any case, scientists are hard pressed to find answers and are thereby examining data even from the past to see if there are any tangible links.
Because of the starfish's pivotal role in marine habitats, researchers have been issuing a 'citizen call-to-arms' by asking divers, snorkelers, surfers, beachgoers and tidepoolers to be on the lookout and take photos of these sick starfish and/or their limbs. The photos, in turn, can be tweeted with the hashtag #sickstarfish to help the scientific community get to the bottom of this mystery. There is also a website to keep track of the sightings, and it can be accessed by clicking here.
According to Cornell University marine epidemiologist Drew Harvell, "We suddenly need the fine scale, widespread data that only citizen science will be able to provide us."