A Massive Die-Off: What’s Killing West-Coast Starfish?

I first wrote about Pacific sea stars falling victim to a mysterious disease last fall for High Country News. The starfish are turning into goo and dying, and the aptly-named “starfish wasting syndrome” has not—as scientists hoped—subsided on its own.

It’s gotten much, much worse.

How much worse, you ask? Well, from the get-go, this iteration of starfish wasting was more widespread and severe than previous outbreaks, which have historically spiked during warm-water El Niño years and then quickly subsided. By the time it was identified late last summer, the disease had already caused localized die-offs of up to 95 percent of ochre sea stars in Santa Cruz, and was spotted as far north as Alaska. Tens of thousands of starfish simply wasted away and died, literally before researchers’ eyes.

Yet it seemed for a while that Washington and Oregon would be spared. This May, just a little more than 1 percent of ochre sea stars in Oregon were affected.

But now—just a little more than a month later—an estimated 30 to 50 percent are dying, and scientists predict a 100 percent mortality rate in some places. In parts of Washington’s San Juan Islands, mortality jumped from 10 to 40 percent over the course of a single week in June, and the disease has now been confirmed in more than a dozen species.

“This is an unprecedented event,” says Bruce Menge, a marine biologist at Oregon State University. “We’ve never seen anything of this magnitude before.”

You might be wondering what’s behind this intertidal horror show. Funny you should ask. Though the outbreak has prompted a slew of research and emergency funding from the National Science Foundation, no one really knows. We’re 11 months into an epidemic that could wreak havoc on entire ecosystems from Mexico to Alaska, and we can’t pin down the cause.

That’s because unlike, say, salmon or even sea cucumbers, starfish aren’t commercially important, so research until now has been scarce. When Cornell University marine epidemiologist Drew Harvell was dispatched to Washington this year to study the dead invertebrates, for example, she was forced to set up a makeshift lab in a fish-virus facility. Funding for her work is “limited.”

Nonetheless, Harvell and her colleagues have managed to identify bacteria and viruses in sick starfish that don’t seem to be present in healthy ones. But since no one really knows what a sea star’s “normal” microbiome looks like, they still don’t know whether the microbes are causing the disease or are an effect of it. Even if they’re able to figure that out, the disease’s mode of transmission from one starfish to the next is still unclear.

All of this underscores the need for better marine science funding. The ocean is at least as important to our future, our livelihoods and our sense of wonder as outer space, and yet the National Oceanic and Atmospheric Administration gets only about $5 billion to NASA’s $17 billion. A report card from the national ocean advocacy group Joint Ocean Commission Initiative gives the U.S. a D- in its funding for ocean science and calls the field “chronically underfunded.”

That may help explain our tenuous grasp of how carbon emissions, overfishing, development and other human activities fit together to impact the health of the world’s oceans—and why, when disease strikes, we’re often left scratching our heads. This year, for example, some 367 sea lions—more than five times the average—have washed up sick in northern California (and 600 have washed up in Southern California). Puffins are disappearing from the Northeast. A strange virus is afflicting some 1,200 dolphins on the Eastern Seaboard. In each case, we’re not quite sure why. Warming and acidifying oceans likely play a role, but the complete picture is still fuzzy.

The lack of concrete information also provides fertile ground for conspiracy theorists, particularly those who like to blame all mysterious ocean problems on Fukushima radiation—an idea roundly dismissed by scientists. But without better collaboration, funding and research, the real root of these diseases remains speculative.

As Seattle Aquarium veterinarian Lesanna Lahner told reporter Kate Lunau, “This is one of the largest wildlife die-offs that we know of. It’s a signal in the ecosystem that something’s not right.”

Krista Langlois is an editorial fellow at High Country News, where this article was originally published. The author is solely responsible for the content.