Watching the devastating decline of starfish

I went to the beach last week to see some starfish with three trained volunteers. What we found was a scene of devastation on the pier and along the beach at Lofall, located on Hood Canal in North Kitsap.

Barb Erickson photographs a sea star afflicted with sea star wasting syndrome. Photo by Meegan M. Reid
Barb Erickson photographs a sea star afflicted with sea star wasting syndrome. Another infected star dangles by one arm.
Photo by Meegan M. Reid

What had been a large population of sea stars, as scientists call them, were now generally missing. Those that remained were mostly dead or dying. Healthy ones were in a minority.

Sea star wasting syndrome is now clearly present on our local beaches, just as it has affected hundreds of locations from Alaska to Mexico.

On Friday, I was fortunate to be in the company of three women who knew quite a bit about sea stars. They were careful in their observations and precise in their measurements, able to provide data to a network of observers measuring the progress of this disease along the West Coast.

But these three women — Barb Erickson, Linda Martin and Peg Tillery — also expressed their feelings of loss for the sea stars, a creature considered a key part of a healthy marine ecosystem.

As I reported in my story, published Sunday in the Kitsap Sun, Barb was the first to assess the situation as we arrived at the beach, comparing her observations to just two weeks before.

“‘Oh my!’ shouted Erickson as she reached the base of the pier and took a look at the pilings. ‘I can see right now that there are hardly any (sea stars) here. These corners were just covered the last time. Now these guys are just about wiped out.’”

“’Look at the baby,’ lamented Tillery, pointing to a tiny sea star. ‘He has only four arms, and he’s doing that curling-up thing … We had so much hope for the babies.’”

Melissa Miner, who is part of a coastwide monitoring program, told me that researchers are working hard to find a cause of the advancing affliction. But so far no consistent pattern has emerged to explain every outbreak.

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A leading hypothesis is that something is causing the sea stars to be stressed, weakening their defenses against the bacteria that eventually kill them. The stressor could be temperature, she said, or possibly other factors such as increased acidity or low-oxygen conditions. Perhaps another organism attacks the immune system, leaving the sea stars vulnerable to an opportunistic bacteria.

Researchers may find multiple pathways to the same conclusion: a dramatic decline in the sea star population, both at the local level and throughout their range along West Coast.

When I hear about a population crash, I think about the basic tenets of population dynamics. Is it possible that the sea star population has reached an unsustainable level, given the available food supply and other factors, and that widespread disease is a natural outcome? Will the decline of sea stars be followed by an overpopulation of mussels or other prey, leading to a decline in ecosystem diversity? How long will it take for the sea stars to recover? These are issues worthy of study in the coming years.

But I’m haunted by another prospect. Having seen our familiar starfish attacked by strange bacteria and turned to mush, what lies in store for other marine organisms? Could ecological stress and other mysterious pathogens lead to the devastating loss of other marine species? Who will be next?

Peg Tillery, Linda Martin and Barb Erickson take notes on the sea stars they see clinging to the Lofall pier. Photo by Meegan M. Reid
Peg Tillery, Linda Martin and Barb Erickson take notes on sea stars clinging to the Lofall pier.
Photo by Meegan M. Reid

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