UF water researchers develop prediction system for harmful algae

Jan 19, 2026

4 min

David Kaplan


The slimy algae topping Florida’s waterways are more than just unsightly. They are often toxic to humans, animals and the environment.


To mitigate those risks, University of Florida researchers are collaborating with North Carolina State University and University of South Florida scientists on a next-day prediction model to warn and inform water managers about harmful algal blooms.


The research is funded by two U.S. Army Corps of Engineers grants for two phases, totaling $4.4 million. The project is led by David Kaplan, Ph.D., a professor with the Engineering School of Sustainable Infrastructure and Environment in the Herbert Wertheim College of Engineering and director of the Howard T. Odum Center for Wetlands, and Mauricio Arias, Ph.D., an associate professor at USF.



In a paper published recently in the Journal of Environmental Management, Kaplan, UF assistant professor Elise Morrison, Ph.D., and NCSU’s Maria Menchu Maldonado, Ph.D., chronicled their work with harmful algal blooms in the Caloosahatchee River and Estuary, the environmentally sensitive link between Lake Okeechobee and Florida’s southwestern coast. Maldonado performed the work under the guidance of NCSU collaborator Natalie Nelson.


In a collaboration between multiple colleges, organizations, departments and universities, the paper’s other authors are Eric Milbrandt of the Sanibel-Captiva Conservation Foundation, Edward Phlips of UF and Natalie G. Nelson of NCSU. The project’s facilitators include Darlene Velez, research coordinator with the UF Water Institute, and Lisa Krimsky, Ph.D., a water resources regional specialized agent with IFAS.



Using water samples and computer algorithms, the team developed prediction models based on two water sources feeding the river: Lake Okeechobee and the river’s watershed – the water run-off from the surrounding land. The models determine levels of chlorophyll-a, which is a pigment in algae that is indicative of algal bloom conditions.



“For watershed-dominated conditions, the model was able to predict 49% of the variation in next-day chlorophyll-a, which isn’t bad, but for lake-dominated conditions, the model was much better, explaining 78% of the variation in next-day chlorophyll-a in the water,” Kaplan noted.


Unlike traditional forecasting models for algal blooms, which are often complex and require much computing power, these models are designed to be practical for daily decision-making, particularly for the Southwest Florida Water Management District (SWFWMD), which has made improving the health of the Caloosahatchee Estuary a state priority.


Ultimately, researchers want to develop an algae-prediction system and tools for water managers to reduce risks in all freshwater bodies.


“Definitely, this model could be expanded with the use of more data,” said Maldonado. “The same procedure could be applied in other lakes that are highly managed. And this could be done around the world.”


Algal blooms in Florida’s lakes, rivers and estuaries have caused significant environmental and economic damage in recent years, UF researchers contend. Blooms are becoming more frequent and longer lasting.


The initial project – called Coupling Lake, Estuarine, and Watershed Models for the Caloosahatchee River and Estuary (CLEW) – designed data- and model-driven guidance for Lake Okeechobee water releases.


“The overall motivation is that Lake Okeechobee is a challenging natural resource to manage, particularly deciding when and how much water to discharge from the lake to either estuary,” Kaplan said. “There are many competing needs surrounding management of the lake, which has only so much volume. We don't want to cause flooding or other ecological harm.”


The follow-up project is UF’s collaboration with USF to develop tools for end users, meaning agencies and managers to make better decisions. The team wants to deliver a system where water managers press the button to get the one-day risk forecast.


The study was organized to predict whether the algae-toxin risk is low, medium or high.


“In this case, there is a threshold of algal organisms that is considered harmful,” Maldonado said. “Those waters carry phytoplankton species, a microscopic algae that produce toxins. They can be dangerous to swim in, and they can be harmful to the environment. It can be a liver toxin.”


Beginning in the late 19th century, the Caloosahatchee River and its watershed underwent extensive modifications that significantly altered the hydrology of the region, according to SWFWMD. The once-shallow river was deepened and widened into a regulated waterway that was connected to Lake Okeechobee and the Kissimmee Chain of Lakes for navigation, water supply and flood control purposes.


“Water quality is a challenge in Lake Okeechobee, including sometimes pretty bad harmful algal blooms,” Kaplan said. “And then, of course, the downstream recipients of whatever water is discharged are very sensitive to the amount of water they're getting and what's in it. They’d prefer it to be only the right amount at only the right times with the best quality."
Connect with:
David Kaplan

David Kaplan

Professor

David Kaplan studies connecting ecosystems, the hydrologic cycle, and humans with the goal of advancing natural resources conservation.

GroundwaterRiversSpringsHydrologyWetlands
Powered by

You might also like...

Check out some other posts from University of Florida

4 min

Researchers warn of rise in AI-created non-consensual explicit images

A team of researchers, including Kevin Butler, Ph.D., a professor in the Department of Computer and Information Science and Engineering at the University of Florida, is sounding the alarm on a disturbing trend in artificial intelligence: the rapid rise of AI-generated sexually explicit images created without the subject’s consent. With funding from the National Science Foundation, Butler and colleagues from UF, Georgetown University and the University of Washington investigated a growing class of tools that allow users to generate realistic nude images from uploaded photos — tools that require little skill, cost virtually nothing and are largely unregulated. “Anybody can do this,” said Butler, director of the Florida Institute for Cybersecurity Research. “It’s done on the web, often anonymously, and there’s no meaningful enforcement of age or consent.” The team has coined the term SNEACI, short for synthetic non-consensual explicit AI-created imagery, to define this new category of abuse. The acronym, pronounced “sneaky,” highlights the secretive and deceptive nature of the practice. “SNEACI really typifies the fact that a lot of these are made without the knowledge of the potential victim and often in very sneaky ways,” said Patrick Traynor, a professor and associate chair of research in UF's Department of Computer and Information Science and Engineering and co-author of the paper. In their study, which will be presented at the upcoming USENIX Security Symposium this summer, the researchers conducted a systematic analysis of 20 AI “nudification” websites. These platforms allow users to upload an image, manipulate clothing, body shape and pose, and generate a sexually explicit photo — usually in seconds. Unlike traditional tools like Photoshop, these AI services remove nearly all barriers to entry, Butler said. “Photoshop requires skill, time and money,” he said. “These AI application websites are fast, cheap — from free to as little as six cents per image — and don’t require any expertise.” According to the team’s review, women are disproportionately targeted, but the technology can be used on anyone, including children. While the researchers did not test tools with images of minors due to legal and ethical constraints, they found “no technical safeguards preventing someone from doing so.” Only seven of the 20 sites they examined included terms of service that require image subjects to be over 18, and even fewer enforced any kind of user age verification. “Even when sites asked users to confirm they were over 18, there was no real validation,” Butler said. “It’s an unregulated environment.” The platforms operate with little transparency, using cryptocurrency for payments and hosting on mainstream cloud providers. Seven of the sites studied used Amazon Web Services, and 12 were supported by Cloudflare — legitimate services that inadvertently support these operations. “There’s a misconception that this kind of content lives on the dark web,” Butler said. “In reality, many of these tools are hosted on reputable platforms.” Butler’s team also found little to no information about how the sites store or use the generated images. “We couldn’t find out what the generators are doing with the images once they’re created” he said. “It doesn’t appear that any of this information is deleted.” High-profile cases have already brought attention to the issue. Celebrities such as Taylor Swift and Melania Trump have reportedly been victims of AI-generated non-consensual explicit images. Earlier this year, Trump voiced support for the Take It Down Act, which targets these types of abuses and was signed into law this week by President Donald Trump. But the impact extends beyond the famous. Butler cited a case in South Florida where a city councilwoman stepped down after fake explicit images of her — created using AI — were circulated online. “These images aren’t just created for amusement,” Butler said. “They’re used to embarrass, humiliate and even extort victims. The mental health toll can be devastating.” The researchers emphasized that the technology enabling these abuses was originally developed for beneficial purposes — such as enhancing computer vision or supporting academic research — and is often shared openly in the AI community. “There’s an emerging conversation in the machine learning community about whether some of these tools should be restricted,” Butler said. “We need to rethink how open-source technologies are shared and used.” Butler said the published paper — authored by student Cassidy Gibson, who was advised by Butler and Traynor and received her doctorate degree this month — is just the first step in their deeper investigation into the world of AI-powered nudification tools and an extension of the work they are doing at the Center for Privacy and Security for Marginalized Populations, or PRISM, an NSF-funded center housed at the UF Herbert Wertheim College of Engineering. Butler and Gibson recently met with U.S. Congresswoman Kat Cammack for a roundtable discussion on the growing spread of non-consensual imagery online. In a newsletter to constituents, Cammack, who serves on the House Energy and Commerce Committee, called the issue a major priority. She emphasized the need to understand how these images are created and their impact on the mental health of children, teens and adults, calling it “paramount to putting an end to this dangerous trend.” "As lawmakers take a closer look at these technologies, we want to give them technical insights that can help shape smarter regulation and push for more accountability from those involved," said Butler. “Our goal is to use our skills as cybersecurity researchers to address real-world problems and help people.”

2 min

Giant croclike carnivore fossils found in the Caribbean

Imagine a crocodile built like a greyhound — that’s a sebecid. Standing tall, with some species reaching 20 feet in length, they dominated South American landscapes after the extinction of dinosaurs until about 11 million years ago. Or at least, that’s what paleontologists thought, until they began finding strange, fossilized teeth in the Caribbean. “The first question that we had when these teeth were found in the Dominican Republic and on other islands in the Caribbean was: What are they?” said Jonathan Bloch, curator of vertebrate paleontology at the Florida Museum of Natural History. This initial confusion was warranted. Three decades ago, researchers uncovered two roughly 18 million-year-old teeth in Cuba. With a tapered shape and small, sharp serrations specialized for tearing into meat, they unmistakenly belonged to a predator at the top of the food chain. But for the longest time, scientists didn’t think such large, land-based predators ever existed in the Caribbean. The mystery deepened when another tooth turned up in Puerto Rico, this one 29 million years old. The teeth alone weren’t enough to identify a specific animal, and the matter went unresolved. That changed in early 2023, when a research team unearthed another fossilized tooth in the Dominican Republic — but this time, it was accompanied by two vertebrae. It wasn’t much to go on, but it was enough. The fossils belonged to a sebecid, and the Caribbean, far from never having large, terrestrial predators, was a refuge for the last sebecid populations at least 5 million years after they went extinct everywhere else. A research team described the implications of their finding in a new study published in the Proceedings of the Royal Society B. The study’s lead author, Lazaro Viñola Lopez, conducted the research as a graduate student at the University of Florida. He knew his team members had come upon something exceptional when they unearthed the fossils. “That emotion of finding the fossil and realizing what it is, it’s indescribable,” he said. Read more ...

3 min

Charities spend big to defend their board’s corporate agendas, new study reveals

Charities with corporate leaders on their boards spend an average of $130,000 a year lobbying on behalf of their connected companies. That’s according to a first-of-its-kind study that shows how companies benefit from their charitable work — and how charities may be all-too-happy to support their powerful board members in return for lucrative connections. The researchers behind the study say the findings could help policymakers and charity stakeholders keep tabs on a previously hidden form of political influence, but that such arrangements are perfectly legal for now. “Charities stand to gain something by behaving in this way. It doesn’t always have to be corporations pushing charities to behave in a way they don’t want to,” said Sehoon Kim, Ph.D., a professor of finance at the University of Florida and senior author of the new study. “It’s a natural quid pro quo arrangement that arises from the incentives corporations and charities have.” The American Medical Association shows one example of these incentives in action. In the 2010s, they actively lobbied against efforts by federal agencies to curb opioid prescriptions. This benefited companies like Purdue Pharma, the maker of OxyContin widely blamed for exacerbating the opioid epidemic in the U.S. It turned out that Richard Sackler, the former president of the company, sat on the board of AMA Foundation, a relationship viewed by many as controversial at the time. But Sackler had arranged for millions in donations to the foundation, and other charities are likely looking to corporate board members to help engineer large donations for their charitable work by connecting charities to other companies and leaders with deep pockets. Lobbying on behalf of their new friends, then, may simply be the most efficient way to ensure those donations keep flowing. Kim collaborated with UF Professor Joel Houston, Ph.D., and Changhyun Ahn, Ph.D., of the Chinese University of Hong Kong to conduct the analysis, which is forthcoming in the journal Management Science. They painstakingly hand collected data covering more than 400 charities and over 1,000 corporations that identified board connections, donations and lobbying activities that fell both within and outside of the charities’ typical political activity. The researchers focused on larger charities that already engage in some lobbying on their own behalf. These lobbying charities are three times larger than smaller nonprofits that never lobby. After a new corporate board member joined, these charities changed their behavior. They were far more likely to lobby outside of their own interests and to even work to support or defeat legislation that affected their new board member’s company, even when that legislation had nothing to do with their charitable mission. It worked out to about a 14% increase in the charity’s lobbying expenditures. “These were the smoking guns that there’s something going on that’s not supposed to be happening,” Kim said. Because lobbying is such an efficient use of resources, and because charities may lend their friendly brand to these lobbying efforts, this help from charities could significantly benefit these connected corporations. “These are previously unrecognized channels at play in terms of corporate political influence that policymakers need to be mindful of when assessing how influential corporations are likely to be,” Kim said.

View all posts