INDIAN RIVER COUNTY — The Ocean Research and Conservation Association is taking a different approach to studying pollution in the Indian River Lagoon; One that trades broad assumptions for precise, site-by-site data.
Through its Ecotoxicity Program, ORCA scientists collect and analyze water and sediment samples to track nutrients, heavy metals and other indicators of contamination. Those findings are then translated into visual pollution maps that show where pollutants are most concentrated, helping researchers, policymakers and residents better understand what is happening beneath the surface of local waterways.
Dr. Lauren Kleiman, a research associate with ORCA, said the organization’s pollution mapping project was designed to address a common limitation in traditional lagoon studies.
“Some studies that are looking at the health of the Indian River Lagoon only sample a handful of places and then make a lot of assumptions about what’s going on in the whole lagoon,” Kleiman said. “What we do with our pollution mapping project is look at a specific area — our most recent one was in the Sebastian River — and do very dense spatial sampling.”
That intensive approach means long days on the water for Kleiman and her team. During a typical outing, crews may collect data from as many as 20 sites, taking multiple sediment subsamples at each location and gathering water samples for lab analysis.
“These are really long days in the field,” she said. “Some of those samples are being sent out to collaborators or contract labs for analysis, and then we do a lot of our analysis in-house as well.”
The payoff, Kleiman said, is the ability to see pollution patterns on a much smaller scale than most studies allow. Instead of general trends, ORCA’s maps can reveal specific areas where nutrients and toxins are accumulating and where they may be coming from.
“It really allows us to see, at a very small scale, where the pollution is or the accumulation of nutrients and toxins,” she said. “We’re able to locate the hot spots and then try to trace those back to potential sources.”
Those sources can vary widely, from hardened shorelines and drainage canals to marinas and residential areas.
“It really varies,” Kleiman said. “Sometimes it’s a hardened shoreline, sometimes it’s a drainage canal, sometimes around a marina — there can be a lot.”
One of ORCA’s major milestones this year was completing its St. Sebastian River ecotoxicity project, launched in 2024 with support from Impact 100 Indian River. The study focused on one of the lagoon’s key freshwater tributaries and combined dense field sampling with advanced analysis to localize nutrient pollution and other contaminants.
The effort also relied on trained citizen scientists and interns, who helped collect samples, support laboratory work and process data. Their contributions, ORCA officials said, were essential to producing the final gradient maps; visual tools that turn complex scientific data into something the broader community can easily grasp.
“Unless the water is really cloudy or there’s a huge algal bloom, it’s not something that you’re necessarily seeing visually,” Kleiman said. “We make these gradient maps that look kind of like a weather map, going from blue with lower concentrations of a certain pollutant up to red with higher concentrations, and those are very visually intuitive.”
Those maps are more than just educational tools. ORCA uses them to guide targeted monitoring through its Kilroy Network, prioritize restoration through its Land to Sea initiatives and help ensure resources are directed where they can have the greatest impact on lagoon health.
In some cases, the data has already led to on-the-ground action. In one area flagged for high nutrient levels, Kleiman said ORCA began working with nearby homeowners to explore practical solutions.
“With our most current pollution map, we saw an area that has a lot of nutrient pollution, and we’ve started talking to some of the homeowners in that area about installing buffered shorelines,” she said. “That could prevent some of those nutrients from running off into the lagoon.”
Community outreach is a key part of the project as well. Alongside the scientific work, ORCA staff present findings to local groups and hold public lectures to raise awareness and encourage involvement.
“We have internal lectures that we’ll give that are publicized for the community to attend,” Kleiman said. “With the most recent project, I’ve already presented to Friends of St. Sebastian River and the Sebastian River Fishing Club, and I’ll be reaching out to some other community organizations.”
As ORCA wraps up analysis from the Sebastian River study, the team is already looking ahead. Though future projects will depend on securing the funding needed to continue the work.
“They’re very costly to do,” Kleiman said. “So we’re looking for funding for our next one.”