Each day, thousands of students walk past Lake Osceola on their way to class, yet few take the time to appreciate the diversity and rich history of this campus landmark.
Underneath its surface, the lake is home to an array of flora and fauna. Since 1947, it has been a central part of the University of Miami campus. Originally, Lake Osceola was a canal that provided a transit point between terrestrial freshwater systems and Biscayne Bay. Once the university was built, the area was dredged out to become the lake we know today.
Dan DiResta, director of PRISM and senior lecturer in the Department of Biology, began studying Lake Osceola in the 1990s. He said that since the lake was connected to other bodies of water, wildlife began inhabiting the lake naturally.
“Despite being a man-made lake, nothing was introduced,” DiResta said. “Since it was connected to Biscayne Bay, the fish and the plant life migrated in, and then, of course, the birds took advantage of that.”
Jerald Ault, a professor in the Department of Marine Ecosystems and Society, has been observing the lake for 30 years. He said that because of this connection to the bay, wildlife patterns change indefinitely.
“On any given day, there can be a different mix of species or different migratory scale movement,” he said.
The lake’s proximity to the bay allows it to encompass the varying ranges of marine habitats in South Florida. However, the area itself is also considered a special habitat due to the large presence of species at risk of extinction.
“Where else in the USA on a college campus do you see endangered species like manatees, crocodiles and alligators?” DiResta said.
While the lake is diverse in terms of megafauna or large animals, its micro-ecosystem has degraded. Dana Krempels, director of undergraduate studies in the Department of Biology, has noticed these changes through student research projects over the years.
Krempels said that roughly ten years ago, the lake was diverse, but samples of the lake taken about two years ago show only mud, algae and dead insects. She attributes this shift in variety to disturbances that churn the water, like construction work.
Recently, construction for a pedestrian bridge that will connect the Lakeside Patio to the Billings Walkway has been approved, leading to more possible changes to its ecosystem.
“When you start mixing the water up… it’s like how a hurricane doesn’t do much for our diversity here, right?” Krempels said. “It’s the same thing. If we have a micro-hurricane going on in the lake everyday, then, well, that’s what’s going to happen.”
Although it causes a decrease in diversity of microorganisms, the churning of the water also serves a function: to help oxygenate the water.
In the early 1990s, the lake was having problems with stratification. This means that algae was accumulating at the bottom of the lake and being decomposed by bacteria, which in turn consumed all of the oxygen at the lake’s floor. The lack of oxygen resulted in the death of fish and an unpleasant odor.
“The university became concerned about this, so, first, they got the fountain,” DiResta said. “Not only does it look great, but it also has a function to aerate the water. And if you notice, there’s also bubblers around the lake to turnover the water and mix it so that you don’t get this anoxic buildup at the bottom.”
Despite the disturbances to the water, Ault said that life in Lake Osceola has been remarkably unaffected thanks to a movement toward ecological consciousness starting in the early 1970s.
“The lake has remained relatively stable because development around it and nutrients that come into the lake are well-regulated,” he said. “Before, not as much attention was paid to ecological matters. But today, things have changed. The lake has seen an up-check, and now everyone takes care of it, everyone is a guardian of the lake in some way or another.”
As for the future of Lake Osceola, Krempels said that we should not be expecting change anytime soon.
“Since the construction has started, I don’t think it’s changed because it hasn’t had time to stabilize yet,” she said. “Maybe a few years ago it was better, and maybe a few years from now it will recover.”
All of these characteristics have made Lake Osceola a valuable research resource, according to DiResta.
“It’s a perfect laboratory,” he said. “Looking at the dynamics and changes that go in there and how to maintain that vibrant ecosystem in the face of all of these approaching impacts is really interesting.”
Ault agrees that this resource is beneficial to students looking for hands-on research experience.
“The lake provides an interesting quasi-natural laboratory, and it’s totally available,” he said. “Getting out there to reinforce what you learn in the books is important because you need a balance between the theoretical and the empirical, or ‘the real world.’”