Just a little over a year since it was first spotted on B.C.’s coast, starfish wasting disease has come to Barkley Sound.
“We’ve been keeping a close eye on it because we’d been expecting it to come here at some point [though] hoping it wouldn’t,” said Peter Mieras of Rendezvous Dive Adventures.
Mieras, who runs Rendezvous Dive Adventures in Rainy Bay, located near the mouth of the Alberni Inlet, followed news of starfish wasting disease when it popped up in Howe Sound, Puget Sound and on the eastern side of Vancouver Island a little over a year ago.
The disease manifests itself in lesions on the body of the starfish and leads to a deflated appearance and arms falling off. As of yet, no cause has been determined.
“If I knew the [cause] I’d be rich. Cornell University has been looking at what it is,” said Mieras. “As far as my latest information, they have narrowed it down to a bacteria or a virus.”
Starfish wasting disease mainly affects sunflower starfish, morning sun starfish and ochre starfish, all of which can be found in Barkley Sound.
While there is a risk that the disease could seriously decimate or even wipe out the starfish population in Barkley Sound completely, Mieras is hopeful that the less concentrated population in the sound means that won’t happen here.
“In Howe Sound, where the initial outbreaks seem to have taken place, there seems to be a very high concentration of these stars; [you might see] hundreds and hundreds of starfish on a regular dive. Here you might see 50-60 starfish.”
“Those large concentrations make it way more prone to spreading than in a place where the population density is lower.”
If the disease does spread, it could have serious repercussions for the rest of the Barkley Sound ecosystem.
“Starfish are natural predators to sea urchins [who feed on kelp] and if they don’t keep the sea urchin population in check, that would negatively impact the kelp fields,” said Mieras.
“Kelp fields are important sanctuaries for a lot of fish, so of course there is a domino affect. I don’t know any kind of animal that if it’s taken out in large numbers would not have a domino affect on the ecosystem.”
“If you look at Howe Sound, the sea urchins there have ben taking over quite aggressively.”
There’s also a concern that the starfish are spreading the disease between species of starfish.
“Sea stars like the morning sun star feed on the sunflower starfish and that affects them because they’re the same family and they get the disease as well and die out as a consequence of that.”