Wait until you hear what oysters can really do!

Dr. Patrick Rice, Chief Science and Research Officer for the College of the Florida Keys, joined Good Morning Keys on KeysTalk 96.9/102.5FM this morning to talk about marine aquaculture.

Dr. Rice said, “We’re focusing on black grouper with the idea of what we call conservation aquaculture. This is the idea of culturing things from the marine environment with the goal of putting them back out into the wild. We’ve had our fish in captivity here for about a year now. They’re doing great. They’re all female. They’re getting bigger and fatter every day.”

The system is quite innovative.

Dr. Rice said, “We have lighting that can simulate the sun and the moon. We have temperature control. We even have acoustic systems on the on the tanks to mimic grouper spawning behavior with the hopes that when we get the conditions exactly right, that the females will start making some eggs for us. Then our plan is to get sperm from the males from the wild because the boys are really big and live a lot deeper, and they’re hard to get up to the boat without having issues like barrel trauma. Anybody who’s fished for deep fish and pulled something up quickly knows that swim bladder expands and the eyes bug out. It can be really damaging to the fish so what we’re trying to do is go out during the spawning season and catch the fish and bring them to the boat and then basically extract the sperm from the males and then release them back into the wild and then just freeze the sperm so that when the females are ready, we can fertilize the eggs and hopefully make some babies that we can put back out on the reef.”

The system is a recirculating aquaculture system.

Dr. Rice explained, “That means that most of the water is recycled so that when the fish eat and then have waste, we need to remove that. We have all the right systems in place to do that, but it requires a lot of water change, which is labor intensive. I came up with this idea that if we could use some organisms that live in the wild that like to feed off of the waste of fish and other things, that we might be able to use them as biofiltration organisms. A great example is oysters. Oysters are filter feeders. They sit there all day long, filtering out all the goodies in the water and they’re excellent filter feeders. Also algae, it absorbs the dissolved nutrients, the ammonia and the waste products that are dissolved in the water. So we actually found a funding source that would fund us for another year on this project. So we’re going to put oysters in the system to filter out the waste products from the grouper. Then we’re going to have algae in the system as well, to filter out the dissolved nutrients so that when that water goes back in, it’s much cleaner and we don’t have to do water exchanges as often.”

Another fascinating fact about oysters is they can actually sequester carbon from the atmosphere.

Dr. Rice explained, “One hundred million years ago, the atmosphere had a lot of carbon in it. It was hot, a lot hotter. It was the atmosphere that the dinosaurs were living in and all the trees and plants, they suck up the carbon and when that falls and gets buried underground, it becomes oil. So all of that carbon back then was removed. It was sequestered in the form of oil. Now we’re extracting the oil, burning the fossil fuels and putting that carbon dioxide back into the atmosphere. That’s what’s creating this concept of climate change. It’s much like your car. On a sunny summer day, you open your car and it’s really hot inside. The radiation from the sun comes in, but it can’t escape. That’s the same thing, this carbon dioxide is creating a kind of a transparent blanket, allowing the sunshine to come through but not allowing the heat to radiate back on. That’s what we’re talking about when we talk about carbon dioxide exacerbating climate change.”

But it’s oysters to the rescue!

Dr. Rice said, “Their shell is made of something called calcium carbonate and believe it or not, they’ve got a little enzyme that exists right on the oyster where the tissue meets the shell. It takes carbon dioxide from the atmosphere, combines it with calcium, and forms calcium carbonate and lays it down at 100 million molecules per second. And it goes back and forth. It’s very, very effective at removing carbon dioxide from the atmosphere when it builds the oyster shell. But think about this, there’s something called carbon credits out there. If you can quantify the amount of carbon that you remove from the atmosphere, or don’t necessarily put into the atmosphere, you can actually get funding in the form of these things called carbon credits. So what we’re going to try and do is use this as a research project, not only to clean our water for our grouper aquaculture system, but to maybe quantify how much carbon dioxide is actually sequestered by these little oysters. Then we’re going to work with the oyster industry in the panhandle of Florida to try and help them get the carbon credits that they deserve, so a way for them to make a little bit more money while growing seafood for the industry and the country.”

Mike Stapleford of KeysTalk 96.9/102.5FM said, “Wow, that that is pretty groundbreaking stuff. You certainly are really doing a full blown aquaculture there that is quite regenerative in a number of ways.”

“Yeah,” Dr. Rice confirmed. “That’s not it, though. The algae that we’re going to use loves to absorb nutrients. If you feed that to cattle at 5% of their diet as a supplement, it reduces methane production by 98%. So people might have heard before that cattle farming is bad for the environment because of the cow burps and the methane they produce. That’s because there’s a bacteria in their gut that helps them break down the cellulose and that grass and the result is this methane. Well, enzymes in the seaweed, reduce that methane production by 98%. So now we’re working with an organic cattle farmer in Miami. If we can grow this algae, we’re going to start supplying this organic cattle farmer with some of this algae and hopefully in the future, you can get some climate friendly steak.”

The algae doesn’t interfere with the digestive ability of the cow.

Dr. Rice said, “It actually improves the health of the cattle. It’s not just cows. Any of the ruminants and things that have multiple stomachs and eat grasses, they all do this. So it could actually be applied to other types of meat agriculture.”

Student participation is included in this as well.

Dr. Rice said, “We’ve got two marine research assistants and three internships funded with this next grant. I’m about to apply for an extension of this with the National Oceanic and Atmospheric Administration. The idea for us is to try and educate the future stewards of the marine environment, while making the world a better place.”

There are scholarships available for anyone interested in the program.

For more information, click here: https://cfk.edu/