The Florida Oceanographic Society is changing how it evaluates water quality across the St. Lucie River, St. Lucie Estuary and Indian River Lagoon, moving away from a one-size-fits-all grading system toward standards tailored to each basin.
The nonprofit has relied on volunteer monitoring since 1998 to track long-term trends across the watershed.
“We have members around the community who are trained by staff to go out on a weekly basis to collect various water quality parameters,” said Nate Winn, research associate with the Florida Oceanographic Society. “The purpose of this program, when it was established in 1998, was to capture spatial changes in the water chemistry over time and for us to be able to see how different stressors are affecting the water.”
Those samples are used to determine whether conditions can sustain aquatic life and the habitats that support it.
“Are the water quality parameters that we’re measuring for this week suitable to provide habitat for things like fish, as well as supporting those more structural organisms that supply habitat like seagrasses and oysters?” Winn said.
As the program has expanded across multiple water bodies with very different characteristics, the society began questioning whether a single grading scale still made sense.
“We’re all the way from the St. Lucie River to where it transitions to the estuary to the Indian River Lagoon proper,” he said. “It’s really hard to put a selective criteria to grade all of them the same because these are very different water bodies and there’s a lot of mixing going on. What we’re doing now is taking an opportunity to reevaluate the grading scale that we put on each of those parameters and to see if there’s a need to refine them.”
One issue involves how visibility is factored into scores, particularly in areas where seagrass does not naturally grow.
“How we currently have our grading scale more goes toward the visibility that’s required for seagrass to thrive and other submerged aquatic vegetation, which is important and it’s a really good grading rubric to do that,” Winn said. “But we also have to acknowledge that since these water bodies are so different from each other and some of them don’t even have naturally growing seagrass, it’s a little bit misleading to put one criteria across these different water bodies.”
Instead, the organization is turning to past conditions to define what “healthy” looks like in each zone.
“What we’re trying to do is look at historical data to create kind of a baseline for each one of our testing zones for when there was minimal human impact,” he said.
The revised approach is intended to improve public understanding while strengthening how environmental changes are tracked.
“A part of it is just education, and then the other is by having a better grading scale we’re able to collect more representative data to better monitor how these habitats are truly being impacted in their respective zones,” Winn said.
Some areas will continue using the existing system.
“The reason why we have some zones that are still being graded is we believe that the grading scale that we have in place is more suitable for those zones,” he said.
Winn said the society hopes to have the new grading changes in place by the end of the year.