Sea Stars and Scholars

Sanctuary Shorts - Episode 4
"Sea Stars and Scholars" (6:06)
By Matt Dozier



In the fourth episode of our podcast, "Sanctuary Shorts," we talk to Foster Scholar Nyssa Silbiger about sea star wasting syndrome. [MP3 Download]

NARRATOR: Hello and welcome to Sanctuary Shorts! I'm your host, Matt Dozier, and on this episode we've got a tale of sickly sea stars, invading invertebrates, and the scientific sleuths who are trying to unravel the mystery of what happens when a keystone species goes missing.

NARRATOR: Our story begins on the Pacific coast of North America, where a mysterious illness has been killing sea stars (well, scientists call them sea stars; you may know them as starfish). Since June 2013, millions of these iconic coastal creatures have withered up and died, victims of what has been dubbed "sea star wasting syndrome."

NARRATOR: We still don't know what's causing it, but the epidemic has gotten so bad that in some areas, certain species of sea stars are just gone — completely wiped out, in the span of less than a year.

NARRATOR: That's a big deal for marine ecosystems, since sea stars are regarded as "keystone predators" along the rocky shorelines that make up much of the West Coast.

NARRATOR: But what does that mean, exactly? And what happens to an ecosystem after its sea stars suddenly vanish?

NARRATOR: Those are questions that researchers from NOAA's Office of National Marine Sanctuaries and its partners are seeking to answer, with a little help from a NOAA scholarship program for aspiring marine scientists like Nyssa Silbiger.

NYSSA SILBIGER: My name is Nyssa Silbiger, I'm a Ph.D. student at the University of Hawaii at Manoa, and I'm a Nancy Foster Scholar working here at Monterey Bay National Marine Sanctuary with Steve Lonhart.

NARRATOR: As a recipient of the Dr. Nancy Foster Scholarship, Nyssa is part of an accomplished group of marine science grad students with close ties to our national marine sanctuaries. In addition to her studies in Hawaii, she recently traveled to California for a collaborative research project at Monterey Bay National Marine Sanctuary.

NARRATOR: Working alongside sanctuary research scientist Dr. Steve Lonhart, and Dr. Lisa Needles from Cal Poly San Luis Obispo, she spent six weeks diving in Monterey Harbor to investigate how things are changing in an area ravaged by sea star wasting syndrome.

NYSSA SILBIGER: They're interested in how the recent die-off of all these sea stars is actually affecting the abundance and distribution of this invasive bryozoan.

NARRATOR: A "bryozoan" is a colonial organism, made up of thousands of tiny individual animals. The species in question is Watersipora subtorcata, which looks bit like red leaf lettuce as it grows. Here's Steve Lonhart, the research scientist Nyssa worked with at Monterey Bay National Marine Sanctuary.

STEVE LONHART: Watersipora is one of those species that is a cosmopolitan one; it's found in harbors and estuaries throughout the world, primarily due to its hitchhiking on the hulls of large oceangoing vessels and then invading the ports and harbors that these vessels go to.

NARRATOR: So, harbors are crowded places — not just with boats, but with marine life. Harbor pilings — those pillars made of wood or concrete that hold up docks and piers — are like their own little bustling cities, with all kinds of creatures vying for every available inch of space.

NARRATOR: They're also a good place to study changes in the marine environment, from the spread of invasive species to the impacts of climate change.

NYSSA SILBIGER: I think one of the reasons why the harbors are so great is because it's this permanent structure that you can go to all the time, even if conditions are kind of bad, and look at how the Watersipora is affecting this community during different times of the year.

NARRATOR: Through regular surveys of the species found on these harbor pilings, Nyssa and her fellow researchers have been tracking the balance between Waterispora and other competitors for space — like the mussels that grow in dense clusters along the California coast. And that's where sea stars come into the picture.

NYSSA SILBIGER: The sea stars are really important keystone predators. They're voracious predators on mussels in particular, and these mussels like I said are these important space competitors.

NARRATOR: As you might have guessed, those sea stars aren't doing so well.

STEVE LONHART: One of the most important of the sea star predators in the rocky intertidal of central California is the sea star that's in the genus Pisaster. These Pisaster stars were also very severely depleted by the sea star wasting syndrome.

NARRATOR: So, that raises the question: without their main predator around to keep them in check, won't mussels be free to expand like crazy? What happens to the Watersipora? Will it flourish, as well, or get crowded out? And what does that mean for the rest of the species that make their home along California's rocky shores?

NARRATOR: The answer, at this point, is that we just don't know! And that's what makes this research so important.

NYSSA SILBIGER: By removing this one species, you're actually having this effect that goes all the way down the system — not just affecting the mussels, but affecting other things such as invasive species. So it really could show how sensitive ecosystems are to a change of one small thing.

NARRATOR: It's also the kind of research that the Dr. Nancy Foster Scholarship Program, which encourages participants to work closely with the national marine sanctuaries, is ideally suited to support.

STEVE LONHART: Well the addition of a Nancy Foster scholar to a sanctuary site is, I believe, invaluable. It's invaluable for both the person who's coming into the program, so, the graduate student, but it's also a real help to the sanctuary staff itself. Within the research program, because of the many limitations we have in terms of what we can do, adding a staff person, essentially — for even a short-term period — allows us to delve into some topics more deeply than we would on our own, so it really opens up doors for us in terms of the research that we can do.

NARRATOR: These collaborations open doors for the scholars, as well.

NYSSA SILBIGER: The Nancy Foster Scholarship is amazing. It's given me so many opportunities to get a more diverse idea of what's going on in marine science throughout the country, particularly in the sanctuaries. It's been a wonderful experience, and I would encourage anybody that wants to work within the sanctuaries to apply to this.

NARRATOR: A big thanks to my guests, Nyssa Silbiger and Dr. Steve Lonhart; if you're interested in learning more about the Dr. Nancy Foster Scholarship Program you can visit its brand-new website at www.fosterscholars.NOAA.GOV.

NARRATOR: That's it for this episode of Sanctuary Shorts, brought to you by NOAA's Office of National Marine Sanctuaries. I've been your host, Matt Dozier, and thanks for listening.