The number of juvenile sea stars along the Oregon coast is exploding, just two years after wasting disease nearly wiped out populations.
But that doesn’t mean the threat of disease is over, researchers from Oregon State University said in a study published this week in the journal PLOS One.
“Whether they can make it into adulthood and replenish the population without succumbing to sea star wasting disease is the big question,” OSU marine biology professor Bruce Menge, the lead author on the study, said in a news release.
Sea star wasting syndrome arrived on the Oregon coast in April 2014. The fatal condition causes sea stars, also known as starfish, to literally melt.
The epidemic ranged from Alaska to Baja, California.
Over a period of about 15 months, the disease reduced the sea star population in Oregon by as much as 84 percent at some sites. Populations of the dominant species, purple ochre sea stars, were decimated by as much as 99 percent.
"We're talking between 60 to 80 percent of the sea stars in all the populations gone within a couple months," said Oregon State University researcher Sarah Gravem.
Since then, researchers have observed as many as 300 times the normal number of juvenile sea stars.
"In a normal year you see a couple babies... the babies were just covering the rocks and I'd never seen anything like it," Gravem said.
Menge and his colleagues believe the reason for the high survival rate is the availability of more food. The young sea stars feed on larval and juvenile mussels and barnacles, competing with adult sea stars for the same food source. The scarcity of adults provided a temporary smorgasbord for the juveniles.
The study also found that during the past two years, the number of gooseneck barnacles along the coast has grown, likely because there are fewer adult sea starts to prey upon them.