There’s a plague currently afflicting starfish along the North American West Coast. Called sea star wasting disease, it’s a terrifying affliction that causes echinoderms to tear themselves apart. Now, for the first time ever, the disease has been spotted in northern waters—a possible consequence of global warming.
The recent discovery of sea star wasting disease in Haida Gwaii, an archipelago on the North Coast of British Columbia, Canada, indicates that the plague is spreading beyond the waters of Washington and the southern coast of BC. The mysterious and gruesome disease, which is estimated to have killed millions of starfish on the West Coast, starts with lesions, followed by bodily fragmentation, and ultimately death.
The exact cause of the disease is still unknown, but last year a Cornell research team identified a possible culprit — densovirus (SSaDV) — a pathogen also found in cockroaches and sea urchins.
Some scientists hypothesize that rising water temperatures are exacerbating the epidemic; as Cornell University marine epidemiologist Drew Harvell told PBS back in June 2014, “A warmer world would be a sicker world. Under warming conditions a lot of microorganisms do better. They grow faster. They replicate faster. Many of our hosts can actually be stressed by warm conditions. And so it kind of creates a perfect storm of sickness.”
And as ecologist and evolutionary biologist Peter Raimondi noted late last year in a UC Santa Cruz release about the densovirus study, “The fact that [the epidemic] has occurred historically indicates that while this virus may be the agent that causes the disease, something may have happened recently that caused it to go rogue, because we’ve never seen anything like the current outbreak.”
All this said, no causal link has been established between the epidemic and warming waters. As Raimondi made clear, warm water may be an unlikely factor due to the wide range of locations that have been affected. More monitoring and research is clearly required before any kind of linkage can be established, but the presence of the disease in northern waters is certainly cause for concern.
Top photo: USGS.GOV/Kevin Lafferty