Starfish from Alaska down through California have been struck by a mysterious, deadly disease that causes them to lose limbs or even completely dissolve into white gelatinous goo. The wasting syndrome has struck at least 10 species of starfish (also known as sea stars) and its exact cause remains unknown, according to the University of Santa Cruz, which has been tracking the ecological destruction.
A similar wasting syndrome has been observed on the East Coast, where it has been linked to a virus that follows a period of starfish overpopulation. On the West Coast, however, the only observed factor for the starfish wasting syndrome has been warmer-than-usual waters (which could conceivably create a breeding ground for dangerous bacteria). The West Coast syndrome has caused two previous mass starfish die-offs, the first in 1983-1984 and the second from 1997-1998. The current die-off appears to have begun this past summer and is already much greater in scope than any previous events.
Whatever the cause of this wasting syndrome, the effects have been dramatic. The starfish first develop lesions that quickly expand. Starfish begin to lose limbs and then completely dissolve. "They essentially melt in front of you," Pete Raimondi, chairman of UC Santa Cruz's Department of Ecology and Evolutionary Biology, told the Press Democrat. All of this occurs within just a few days or weeks of the first symptoms.
As many as 95 percent of starfish populations have died off in some affected regions. Although many species are affected, the worst hit has been Pisaster ochraceus, a 20-inch-wide species commonly known as either the purple or ochre sea star. Raimondi told the Press Democrat that this particular sea star is a "keystone species" that eats mussels. Without the starfish to control mussel populations, mussels will multiply to the point of possibly crowding out other tidal species.
The school has been monitoring sea star populations for some time, and its data is available as an interactive map or by individual species or location. Researchers have asked citizen scientists to observe the starfish in their own areas and report any changes in population.
Meanwhile the Vancouver Aquarium has been tracking the die-off for several months. The video below demonstrates the devastating effect of the wasting syndrome on Hutt Island. In the first half of the video, the ocean floor is almost completely covered with starfish. In the second half — shot just a few months later — they have all disappeared.
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