After over a year of tirelessly collecting data and toiling away in laboratories, scientists have discovered some important information on the mystery of the sea star wasting disease that has plagued sea stars off the west coast of North America.
A scientific paper published recently cites densovirus, a virus commonly found in invertebrates, as likely being involved in the complex syndrome. This research was led by Dr. Ian Hewson of Cornell University and supported by organizations and aquariums all over North America, including the Vancouver Aquarium. Dr. Martin Haulena, head veterinarian, and Dr. Jeff Marliave, the vice president of marine science, are co-authors of the paper.
Aquarium researchers started noticing signs of sea star disease in local waters in September 2013. They noticed several sea star species affected by a variety of lesions including missing arms, necrosis, degeneration and “melting.” Tissue samples were taken by veterinary staff and sent to Cornell University for analysis.
While this mass mortality event was concerning in itself, it also appears to have affected other wildlife. Sea urchin populations in Howe Sound have exploded in the absence of predatory sunflower stars. The sea urchins are eating the kelp, which normally provide habitat for fishes and other animals including spot prawns. This timelapse video taken at the Vancouver Aquarium shows the effects on sunflower sea stars:
“This is really important information, but for every question answered we get a whole new batch of questions that need answers,” said Dr. Haulena on the recent findings. “One of the great things about this issue is the tremendous amount of collaborative effort that is going on – from citizen scientists and divers to some of the world’s experts at various universities and aquariums. People are aware and concerned about their environment and everyone is working really well together to help solve this mystery.”
Even though part of the sea star wasting mystery has been solved, scientists still don’t know the exact ecological role of the virus, what cofactors may be involved to cause the disease and what the long-term impacts may be. In the meantime, Aquarium researchers will continue to monitor the sea stars in local waters and work with local divers to collect data.