When the stars go out all along the coast
A victim of the mysterious killer at Seabeck. Credit: Pete Garland
Pete Garland ponders what he’s seen on his beach with mixed horror and awe. “It was just white gelatinous material, with a little bit of lattice – otherwise you wouldn’t know what it was. It was amazing. And for an engineer like me, it was all quite new.”
Last November, after retiring as a mechanical engineer and searching long and hard, Garland found his dream spot on the water, at Seabeck on the Hood Canal. There he set out to enjoy the wonders of nature he hadn’t had time for before. He marveled at the diversity of life wriggling, burbling and, in the case of the sea stars, almost imperceptibly crawling on his 90-foot patch of tideflat.
In April he took a Kitsap Beach Watchers class with Jeff Adams, an extension agent at Washington Sea Grant, a UW-based marine science and education program where, let it be disclosed, I also work. He became what’s loosely called a “citizen scientist,” one in the growing networks of volunteers who monitor their designated plots of earth and water for early warnings of environmental change. Adams alone has organized about 20 such monitors at eight sites along South and Central Puget Sound and the Canal.
Adams alerted Garland and the other monitors to watch especially for one phenomenon, the latest and perhaps strangest in a string of mysterious catastrophes to afflict local waters in recent years. It’s called “sea star wasting syndrome,” and it unfolds like an invertebrate horror movie: Sea stars (the preferred term for what we used to call “starfish,” since they aren’t really fish) weaken and wither like deflated balloons. Sometimes their arms crawl off from their collapsing cadavers like rats fleeing a sinking ship. They die en masse.
This syndrome was first noted three years ago on the shores of Olympic National Park. It appeared next in the tideflats of Seattle and Vancouver, BC, and has since been reported along the Pacific coast from San Diego to Southeast Alaska.
Some areas, however, seemed to be mysteriously spared. Hood Canal was one. When he started monitoring in April, Garland recalls, “we’d see clumps of five or so stars every 10 to 15 feet. They seemed to be doing just fine. I went out about two weeks ago and everything was okay. Four or five days later, there was nothing – maybe four or five decaying pieces, where before there were 40 or 50 healthy stars. You couldn’t even tell it was a star at first.
”Before we could sit in our house and see these purple mats” where the stars were. “Now there’s nothing.”
In June, other monitors sent Jeff Adams similar reports from other sites on Hood Canal, Dyes Inlet, and Vashon and Maury Islands. Stars in other areas such as the Oregon Coast and San Juan Islands that had previously escaped the “syndrome” have also been laid waste.
This isn’t the first sea star wipeout. “In Southern California it’s been a persistent phenomenon,” says Melissa Miner, a Bellingham-based biology professor with the University of California at Santa Cruz who coordinates a (Washington) statewide marine monitoring group (and whom Jeff Adams enlisted to help train his volunteer monitors on a tideflat trek last New Year’s Eve).
“The earliest records I’m aware of are in the 1970s. But it was associated with warm water, with big events occurring in big el Niño years. And there were huge losses of other echinoderms, urchins and sea cucumbers. This one seems to be restricted to just sea stars, and it’s much more geographically widespread. Even with temperature, the patterns don’t match up everywhere. In some places there are correlations with warmer waters, but that’s not the case everywhere”
That’s led some scientists to hypothesize that a pathogen, perhaps a parvo virus residing in the shellfish they eat, is to blame. Other commentators have suggested such factors as oceanic warming, declining prey, and land-based pollution, and, for antinuke conspiracists, Fukushima radiation. But the fact that the die-offs showed first off Washington rather than in warmer California waters suggests that temperature is at most merely an accessory to the crime.
As for pollution, Adams notes that “the geographic scope takes sewage outfalls out of the picture — they’re not a big issue on the British Columbia and Alaska coasts,” where sea stars are also dying. And the stars “have healthy gonads popping out of wasted arms, so we know they aren’t nutritionally stressed.” Like other animals with more sense than humans, sea stars don’t go into breeding mode unless they have enough to eat.
DNA sequencing and other tests may soon home in on a culprit. Miner says she can’t discuss such questions till an upcoming paper is published. But one tantalizing observation seems to support it: Sea stars in one tank at Santa Barbara’s aquarium were fed mussels harvested from local waters, and wasted away. Stars fed frozen squid in another tank stayed healthy.
Sea stars may be charismatic as seabottom invertebrates go (heck, I edit a newsletter called Sea Star). But the mystery isn’t just about them. Slow though they may seem, they are voracious predators, at the top of the tidal food web — “keystone predators,” as they say in the marine biology trade. Their removal can trigger a cascade of ecological changes, just as the extermination of wolves and cougars from most of the United States has led to an explosion of tick-spreading, garden-munching deer.
It’s ironic that the biggest sea star die-off should happen on this coast. First, because the West Coast is to sea stars what Alaska is to bears and Kenya to marathon runners: home to the biggest and speediest species in the world, the meter-wide sunflower star. And second, because the very concept of “keystone species” – itself a keystone of ecology and conservation biology – was first articulated by a UW zoologist named Robert Paine in 1969, based on his study of the common local purple sea star, Pisaster ochracues.
That’s the same star that Pete Garland saw first thrive, then turn into mush on his Seabeck beach. Paine demonstrated the keystone principle by removing purple stars from a beach out at the Makah reservation and observing the effects. Now we see that experiment repeating itself, on a continental scale.