Sept. 20, 2003 — Does a humble scientist at the University of the Virgin Islands St. Croix campus have the formula for ending world hunger? Dr. James Rakocy, director of UVI's Agricultural Experiment Station, has spent more than two decades turning a relatively unknown fish into a major cash crop through the science of aquaculture — the raising of fish in a controlled environment.
Rakocy says his interest in fish began at age 12, when he was a boy with an aquarium, raising them and selling them to pet stores. At age 17, he traveled to the African nation of Sierra Leone and says, "I saw much malnutrition."
As a biology major at the University of North Carolina, he did extensive study of wastewater treatment and water quality. By graduate school he was putting his interest in fish and his studies together, combining civil engineering and aquaculture.
"For my research I developed an intensive tilapia culture system that was integrated with the production of aquatic plants (water chestnuts, watercress, aquarium plants, etc.) It was a great hit and everyone came out to look at the system," he said.
For the past 23 years at UVI, Rakocy has been looking at that original system and developing new systems for what was to become his favorite aquarium pal, the tilapia.
Q: You saw some things that sparked your interest and you also had an opportunity to put UVI on the world map, as far as aquaculture is concerned. How so?
Rakocy: I was given the honor of being a keynote speaker at the European Aquaculture Society in Trondheim, Norway [in August 2003]. The theme of their conference is "Beyond Monoculture," and that's what we've been doing here for many, many years: looking at integrating aquaculture with vegetable production. They invited me to be a keynote speaker of a session on the economics of integrated systems. I was the moderator of the session.
Q: Do you have integrated systems at your fish farm at the UVI St. Croix campus?
Rakocy: Yes, we have two. The aquaponics that we've been working on — that's integrating fish culture with vegetable hydroponics in a recirculating system — we've grow both species in the same system. Then the other system that we have, is green-water tank culture, where we take the sludge from the fish culture operation and use it to fertilize and irrigate field crops, so all our systems are essentially integrated. That was what they wanted to learn about at the conference.
Q: Do farmers on St. Croix get your fish sludge?
Rakocy: Actually some do. They come out here every week and they pump it into five gallon buckets and carry it to their farms. I've actually heard farmers saying it's "liquid gold." It's a complete fertilizer, the fish sludge.
Q: It sounds like you're on the cutting edge of things, among people who are producing one-third of the food fish in the world want to know more about. What is it that they want to know more about, specifically?
Rakocy: The whole theme of this conference which I had a part in was "Beyond Monoculture." When you culture an item like fish and just fish alone, there's a lot of waste that goes into the environment. There's a lot of solid waste, there's nutrient waste. The theme of this conference was to look at ways of capturing that waste and turning it into a useful byproduct. There's a lot of aquaculture today, but the question that arose in the meeting — Is the aquaculture practice today going to be sustainable if we're polluting the environment with this solid waste and these excess nutrients? There were other systems proposed at this meeting, and ways of recapturing it, and our system here was just one of the ways that's being practiced.
Q: Is there anything else, in particular, that you would want the world to know, or the people of the Virgin Islands to know about this particular science you're involved in?
Rakocy: What I want them to know is it's going to become increasingly important in the future and we're going to have to rely more on cultured fish. The United States, for example, is a major fish-importing country. I think that besides oil, that's their second-leading import product. The value of fish is the second-leading import product, behind oil, which is amazing. It's like billions of dollars of fish that we import. So it's really important that we learn to culture them, so we can cut down on that import bill.
I just got the news, the other day, about tilapia, which is pretty amazing. In 2000, tilapia was the 11th most consumed fish in the U.S. It moved up to tenth in 2001, and as of 2002, it's the ninth most popular fish in the U.S. When I started all this research (not that I did this myself), 23 years ago, there were no tilapia consumed in the United States, so tilapia is really gaining in importance.
Q: So, when you look down on a plate, would you see a tilapia smiling up at you, or would it look more like a McDonald's fish sandwich?
Rakocy: If you eat it West Indian style, with the whole fish in the plate, it would be smiling at you, but tilapia actually has made it onto some of the menus of fast food organizations, too, where you just get a filet. I know tilapia is on the menu in Red Lobster, so forth, in the United States. In fact, now in the United States you can practically see it in any supermarket. Worldwide, it's becoming an extremely important fish.
Q: Thank you very much; this has been a really super interview. Just some quick facts and figures — how long has the aquaculture program been running at UVI, how much have you produced and what are some of your major innovations?
Rakocy: I've been here for 23 years and the major achievements are developing two systems that are suitable for dry conditions, like in the Virgin Islands. One is aquaponics, and we have a commercial-scale system running. Just this week we're starting an experiment with raising tilapia in combination with okra and testing out what the productive capacity of okra is.
The other major achievement is developing this tank culture system called green-water tank culture. This is a very, very intensive system that doesn't require much water. In a 20th of an acre you can produce close to 15,000 pounds of fish a year, and then you recycle the nutrients and the wastewater through the irrigation and fertilization of vegetables. We've raised a lot of different vegetables in combination with tilapia culture and we've just received a new grant now to do shrimp farming. We're going to start that this fall … it will be a Pacific white shrimp, the kind that grows in full strength seawater, but these shrimp can tolerate very low salinity levels and we're actually going to grow it in freshwater, in our green-water tank system here at the university. We're excited about that endeavor.
Q: Is there any possibility that aquaculture could save the fishermen in the Virgin Islands?
Rakocy: In Culebra, where they're raising fish in very, very large cages in the ocean. These cages are approximately 3,000 cubic meters. They have two cages they're demonstrating: in one, the culture of mutton snapper, and in the other cage they're demonstrating the culture of a fish called cobia which is from the Gulf of Mexico. These cobia grow at a phenomenal rate, they've grown 20 pounds already this year. There's also somebody here in the Virgin Islands who's on the verge of setting one of these commercial cage-culture facilities in the ocean, off of St. Croix.
So there's the potential that fishermen could become fish farmers and still be working with fish, still be going out on the ocean every day, but now they'd be feeding fish and harvesting them from a cage.
Q: Awesome. Thank you so much.
Editor's note:Rakocy is co-editor of
a two-volume definitive work, "Tilapia Aquaculture in the Americas." In June UVI hosted 33 people from eight states and seven countries for an intensive seven-day Aquaponics and Tilapia Aquaculture Short Course at Rakocy's Agricultural Experiment Station worksite; the photograph is of that class.
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