“Still no babies,” commented Peg Tillery, as we arrived at the Lofall dock in North Kitsap in search of sea stars clinging to pilings under the dock.
“They say there’s a comeback of the little ones,” noted Barb Erickson, “but I’m not seeing any of them.”
Peg and Barb are two of three retired volunteers who first brought me to this site two years ago to explain their ongoing investigation into the mysterious “sea star wasting disease.” Since our first trip, researchers have identified the virus that attacks sea stars, causes their arms to fall off and turns their bodies to a gooey mush.
I first witnessed the devastation in June of 2014, when starfish were dying by the millions up and down the West Coast (Water Ways, June 17, 2014). Lofall, a community on Hood Canal, was just one location where the stars seemed to be barely clinging to life. Now, just a fraction of the population still survives in many locations.
Bruce Menge of Oregon State University recently reported an upsurge in the number of baby starfish on the Oregon Coast, something not seen since the beginning of the epidemic.
“When we looked at the settlement of the larval sea stars on rocks in 2014 during the epidemic, it was the same or maybe even a bit lower than previous years,” said Menge in a news release from OSU. “But a few months later, the number of juveniles was off the charts — higher than we’d ever seen — as much as 300 times normal.”
As Peg and Barb pointed out, the recovery at Lofall has been hit or miss during more than two years of monitoring the site. I became hopeful on my return trip to the dock in January of 2015, when I noticed a mix of healthy adult and juvenile sea stars (Water Ways, Jan. 20,2015).
This week, the young ones were nowhere in sight. Clusters of healthy adult ochre stars were piled on top of each other at the bottom of the piers, waiting for the tide to come back in. I was not sure what to make of it.
“it could be worse,” Barb said. “I think it is neutral news.” Peg agreed, saying, “It could be totally worse.”
Summer has been the period of reckoning in past years, and we should soon know if we are in for another round of disease, which could kill off more of the surviving sea stars, or if the disease is finally on the wane.
Linda Martin, who normally compiles the data, was not along on this week’s trip to Lofall, but other volunteers filled in for her.
“It is an interesting ride,” Barb told me, referring to her experience as a so-called citizen scientist. “It connects you to the larger picture, and you realize that everything is connected.”
It is nice for people in the community to know that this volunteer work is taking place, Barb said, and that someone is watching for changes in the environment.
“People will come up and ask me if there is anything new, people who couldn’t have cared less before,” she said.
For those interested in this kind of volunteer work, a good place to start is Kitsap Beach Naturalists. One can contact Renee Johnson, program coordinator, at firstname.lastname@example.org.
Meanwhile, the cause of sea star wasting disease remains somewhat of a mystery even after its connection to the densovirus, which is associated with dead sea stars but also has been found in some that are free of disease.
A laboratory study led by Morgan Eisenlord of Cornell University found that the disease progressed faster when adult sea stars were exposed to higher temperatures and that adult mortality was 18 percent higher when water temperatures reached 66 degrees F. Temperature was documented as a likely factor in the spread of disease through the San Juan Islands.
But temperatures are not the sole controlling factor, because the spread of the disease has been out of sync with temperature change in numerous locations.
“The sea temperatures were warmer when the outbreak first began,” Menge said, “but Oregon wasn’t affected as early as other parts of the West Coast, and the outbreak reached its peak here when the sea temperature plummeted and was actually cooler than normal.”
Could there be another trigger that increases the virulence of the densovirus?
“Ocean acidification is one possibility, and we’re looking at that now,” Menge said. “Ultimately, the cause seems likely to be multi-faceted.”