The StoryCorps Mobile Tour returned to Fort Myers in February and March 2024 to record meaningful conversations with people right here in Southwest Florida about their lives.
Each Monday, we’re highlighting some of the compelling stories from our fellow Southwest Florida residents.
In this installment, we hear Ernesto Lasso de la Vega speaking with his former boss at the Lee County Hyacinth Control District John Cassani, who would later become the first Calusa Waterkeeper.
Their conversation focused on Cassani’s early research that developed a tool for managing severe aquatic plant overgrowth without the use of herbicides, and how that tool became an industry standard.
Transcript:
JOHN CASSANI: The theme of what we were doing, science and resource management, back then was to try to manage some pretty severe aquatic plant control problems in Florida and the grass carp was what we considered a biological control agent. It was a natural control that we ultimately ended up focusing on as our primary control for some of these certain types of aquatic weeds.
ERNESTO LASSO DE LA VEGA: I realize that this was an innovation because there was some, and we're talking 1983 maybe it's when you publish this document.
CASSANI: I think it's good to give some background and lay a little bit more background before we get into the technical stuff.
LASSO DE LA VEGA: So, what is a grass carp? Explain a little bit of the evolution that leads to the Pioneer development of the triploid grass carp, and to this tool, the is efficient as it is for managing aquatic vegetation.
CASSANI: It's an exotic fish. It's not native to North America, and it was imported into the U.S. in the 1960s and long story short, it became quite a significant factor because it was a type of fish that would eat aquatic weeds, especially the submersed weeds that grow on the bottom and grow up to the water column, like hydrilla. So that's what we did at hyacinth control, was try to use natural controls, or bio control. We realized that grass carp had the most potential. So, the herbicides that were being used, then, the hydrilla weed, this invasive weed from Africa that was taking over Florida lakes and ponds. The Weed became resistant to the herbicides, and so we really depended on grass carp as a bio control, or natural control agent. We actually take a little blood sample from every single fish to verify that it was the sterile version of this species.
LASSO DE LA VEGA: Correct, because what they were afraid is that if you just release a diploid grass carp or regular fish, it will reproduce and it can become another nuisance, another problem. What was the constraints that involved this development? Because we're talking in the 80s.
CASSANI: There was no public internet until 1983. I didn't have a personal computer until 1986; Just research started, and the seed for it was old fashioned science. You know, we’d drive to the University of Florida Library in Gainesville, like, 200 miles from Fort Myers, and we take, like, four rolls of nickels, and we go to the library Xerox machine, it was a nickel a page, and we just made hundreds of copies of these journal articles. And that's what kind of steered us in the right direction for this sort of pioneering research, this kind of technology, invention that we came up with. It took us another probably three or four years to develop the specific method and protocol for pressure shocking these early embryo, this fish's egg, that ended up bringing another set of chromosomes to the developing fish, and basically it looked the same as a normal grass carp. It acted the same. Still ate a lot of hydrilla, but it was functionally sterile. So, what was important was, you had to control the stocking rate and you didn't want it reproducing on site, so you had to control that to effectively use it as a management tool. That's pretty much what we did. People were coming to us from all over the country to find out how we were doing this. Our 15 minutes of fame was really more like a couple of years. And so we had groups like the Imperial Irrigation District in southern Florida. You know, they would divert water from the Colorado River to irrigate the crops down there, and you couldn't put herbicides in the water to control the weeds which were clogging up the irrigation intake pipes. So, grass carp was the perfect tool. They invited us out there. We spent weeks with them producing triploid grass carp. The Canadian Agricultural Department in the province of Alberta was another. They invited us up there. We were the only agency, I think, where we provided these fish free to the public. Every backyard pond owner, every lake resident that wanted to get rid of these weeds, we provided these fish.
LASSO DE LA VEGA: The process of producing the egg and the sperm is not easy. I mean, that was a challenge just to have this skill, to inject the fish the night before, and you came at midnight just to inject the fish, just to have them there ready to spawn at six o'clock in the morning. It was amazing.
CASSANI: Yeah, my secretary, people call. So, we're usually done spawning the fish in early morning. And then people would call sometimes with a complaint or wanted information, and Linda, the secretary, would say, “John's out spawning.” You know, I said “You don't need to say that, Linda,” kind of thing. “I'm not spawning. The fish are spawning,” kind of things. So, it was a kind of an inside joke at the time. It was, from a scientist point of view, it was great fun. We had so much fun doing this, and it was very gratifying to look back after many decades and it helped so many resource managers along the way, especially in Florida where this tropical climate; plants grew like crazy, totally take over. And some of these problems still exist. Lake Okeechobee’s still a big problem with hydrilla and water hyacinth. I still think you should have to drive to Gainesville to the library to figure out how to do research. You know, I'm old fashioned about that.
LASSO DE LA VEGA: I know. Get in the library. Open the journals.
CASSANI: This digital internet stuff’s for a bunch of nerds now.
LASSO DE LA VEGA: They don't get that experience.
CASSANI: You gotta have a lot of nickels though. (Laughter) Thank you, Ernesto, for coming to us, and I think it was probably meant to be.
LASSO DE LA VEGA: Thank you so much, John. I appreciate it.
CASSANI: My pleasure.
JOHN DAVIS, HOST: That was Ernesto Lasso de la Vega speaking with his former boss, John Cassani. The conversation was recorded in Fort Myers through the StoryCorps Mobile Tour. This is WGCU News.
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