In the 1920s, the hardy Pacific oyster was introduced into Puget Sound to replace the more-delicate Olympia oysters, whose numbers were being diminished by pollution. Now, the once-abundant native shellfish are down to less than 4 percent of their historical numbers.
This week Liam walks the tide flats of Case Inlet in south Puget Sound with Betsy Peabody. Peabody heads the Puget Sound Restoration Fund, which is setting the stage for the comeback of the Salish Sea’s native oysters.
Liam Moriarty: What are we up to today, Betsy?
Betsy Peabody: Okay; I’ve brought you to a place where we’re going to search for Olympia oysters. I want you to get a look at them before we head out to search for them because these are very tricky critters to find.
Liam: You’re showing me this little disc that’s maybe about the size of an old silver dollar. It’s grey and pebbly looking and you could easily miss that this is an actual creature.
Betsy: You also want to know where to look for it. This oyster is sort of finicky in terms of where it settles. This one you’re going to find in places that are moist and protected because it’s not very big and it has a pretty thin shell. That’s what we’re going to go out and look for on this scavenger hunt.
Liam: Cool. Alright; let’s go find some oysters!
Liam: Let’s talk a little bit about the Olympia oysters. They’re the native oyster that was here before anybody else showed up.
Betsy: Exactly. And they’re not extinct in this area or along the West Coast. You can still find them in lots of places —
Liam: In the wild?
Betsy: In the wild, and throughout their historic range. But you find them in sparse numbers. It’s really the dense, self-sustaining populations that really provide a big ecosystem benefit for the buck. That’s what we’re trying to rebuild.
Liam: Why are they important? You could say that okay; there aren’t that many of them around because they were the wimps; they couldn’t take it and folks brought in the big, beefy Pacific oysters, they can handle the rough knocks so why are we concerning ourselves with the Olympic oysters?
Betsy: One, they do filter and clean the water because they’re filter feeders.
Liam: What does that mean, exactly?
Betsy: The way that they feed, is that they pull water into their system and they filter out the bits of algae and plankton.
Liam: That’s their food.
Betsy: That’s their food but from our perspective, it increases light penetration and helps support eel grass beds, and we really need good, natural filtration to help maintain healthy estuaries so the water filtration is one reason why we do this. Another is that beds of oysters, those kinds of structured beds I was describing —
Liam: They’re almost like reefs when they all build together…
Betsy: Exactly. Exactly, and they provide a living space for other critters because you can imagine space in between the shells, under the shells, where lots of little copepods — shrimp-like creatures — can nestle, little juvenile crabs … They also provide a good feeding area because again, nestled, in the interstices of these shell, are all sorts of little prey species.
Liam: Fair enough. Let’s go.
Betsy: Okay. We’re going to keep walking but we’re starting to get to denser numbers.
Liam: We’re getting warmer…warmer…
Betsy: Okay — warmer —
Liam: And this is where the hula hoop comes in —
Betsy: Yes; exactly.
Liam: I was wondering; what’s with the hula hoop, Betsy?
Betsy: The hula hoop I brought along because generally when you try to estimate a population, you have a given area …
Betsy: Usually, you’re using a square shaped …
Liam: A grid — I’ve seen — I’ve been out on the beach with researchers using a grid shape.
Betsy:Perfect. But a hula hoop functions in the same way, in the sense that you throw it down, and then you count the number of oysters that you have within that hula hoop. You’ve got one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve. This is a good thing. You don’t find this in many places, and I suppose you have to know that to really appreciate this particular population.
Liam: You guys have gone to considerable lengths, your organization, to foster these guys. How is that working so far?
Betsy: It’s working really well in some places. There are places where we’ve been working since 2005 testing out these habitat enhancement approaches in Liberty Bay, and we’ve sort of doubled the population of Olympia oysters there. It’s working well, and we’re ready to increase the scale of it so that we can try to achieve 10% of Olympia oyster populations in the next ten years.
Betsy: So that is what we’re all searching for; to be able to get this density of oysters really healthy and going strong in other parts of Puget Sound, so that people know there’s something out there that’s been out there for a long time, and there are things we can do on the land to ensure that this place continues to support populations that have fed us for thousands of years.
Liam: Betsy, this has been a lot of fun. Thanks for having me out today.
Betsy: Thanks for coming out.