The Gulf of Mexico—like many elements of the world—has misplaced a lot of its historic oyster reefs. In June 2022, a crew of conservationists from The Nature Conservancy and the Dauphin Island Sea Lab constructed an oyster reef close to Bayou la Batre, Alabama. (If the city sounds acquainted, that could be as a result of it’s the place Forrest Gump began his profession as a fictitious shrimp-boat captain.)
The challenge was half of a bigger effort to guard the group’s eroding shoreline by putting in breakwaters and restoring marshes, together with oyster reefs. However for Lee Smee, a marine scientist concerned within the challenge, it was about finding out one thing evolutionary too: Are you able to scare the oysters into being stronger and extra resilient?
Q: Earlier than you delivered the oysters to Bayou la Batre final June, you first uncovered them to blue crabs. Why would you try this?
Plenty of earlier work has discovered that oysters reply to blue crabs (and different predators like oyster drills) by constructing heavier, stronger shells. We knew that some sort of chemical from the crab triggered the oyster response, and we thought that it was seemingly within the urine.
Q: Why would the oysters want stronger shells?
Effectively, the outdated strategy to restore oysters was placing out some shells, and the oyster [larvae] would land on it and begin to construct a reef. However right here [in Alabama], the pure populations have gotten so low that there are areas the place there’s not sufficient oyster larvae within the water to get the reef going. So we develop them in a nursery and put this stuff out, however then all of them get eaten. So, we mentioned, can we pre-adapt them in a roundabout way?
Q: In order that’s the place these predator crabs, which eat oysters, are available. You mentioned you raised the oysters in tanks with caged crabs in them. Why not simply add crab urine to the tanks?
Crabs have a gap on their face close to every eye that they launch urine from. They really squirt it at one another throughout fights. However it takes us like half of a day to get 20 milliliters of crab urine. And we’d like 600 or 700 milliliters for a two-month challenge to get them to develop. Now, if we will work out what the molecules are [that affect the oysters], then we may make these things, probably. Then it’s simply, “Right here’s the scary juice!” Roll this into your [oyster-growing] tank every single day. However proper now, we’re simply not there but.
Q: You’re engaged on figuring out these molecules although with a few researchers from Georgia Tech. How is that analysis coming alongside?
We’ve recognized two molecules which might be concerned, however they’re not the entire story. We all know that as a result of the best way you do that is you expose oysters to this urine and also you see the best way that the oysters modified. However, there’s all the time variation. A few of them change loads, a few of them change just a little a few of them don’t actually change. There’s all this pure variability. So, we give the urine samples to Georgia Tech they usually analyze them. We’ve pulled two issues from that after which we check them in isolation. And in isolation they form of work but it surely’s not as clear as you’d suppose. So there’s most likely another issues in there that [the oysters] are smelling, not simply these two—however we’re closing in on it.
Q: That is smart.
What’s actually attention-grabbing is once we’re finished we’ll have the ability to ask—that is an evolutionary query—however do oysters odor concern? Or do they odor particular predators?
Do fish odor like fish and crabs odor like crabs? Do blue crabs and stone crabs odor otherwise or are they only crabs? We don’t know. We form of know this: Should you feed [crabs] oysters, they’re scarier than for those who don’t feed them one thing. So it could possibly be that there’s one thing within the food regimen.