ORCA maps pollution in lagoon between Vero bridge spans
By J.G. Wallace
Posted January 26, 2012 at 5:34 p.m.
VERO BEACH — A Fort Pierce-based environmental research group is shining light — bioluminescence, to be precise — on the problem of pollution in the Indian River Lagoon.
Scientists at Ocean Research and Conservation Association, aka ORCA, have started with a pilot program to map pollution in a 1-square-mile area of the lagoon between the 17th Street Bridge and the Barber Bridge in Vero Beach, thanks to a grant from Impact 100 of Indian River County, a women's philanthropic organization.
To find the pollution, scoop up muck from the bottom of the lagoon.
"A lot of people don't realize how much pollution is in sediment," said Edith "Edie" Widder, ORCA's president and senior scientist. "Water moves, and so do the pollutants in it, but sediment stays put, and so do the pollutants in it."
Using a process known as Fast Assessment of Sediment Toxicity technology, Widder mixes the muck with bioluminescent bacteria, marine organisms that emit natural light. She then uses a photometer to see how much and how quickly the light dims as the chemicals kill the bacteria.
The quicker and dimmer, the more pollution.
Widder also looks for nutrients including nitrogen and phosphorus, which she said "aren't technically toxins, but they do plenty of damage" because they stimulate algae growth. Too much algae in the water can lower oxygen levels and kill a wide range of marine creatures. Treasure Coast residents don't have to think back very far to remember the green slime of algal blooms in 2005.
In the Vero Beach study area, Widder's team found the highest levels of nitrogen and phosphates in densely populated residential areas, indicating the pollutants found their way into the lagoon as runoff from overfertilized lawns.
The association found the lowest levels of nitrogen and phosphates directly adjacent to the Vero Beach Country Club, which Widder said correlates to the club's recent transition to using an organic fertilizer in smaller and more controlled applications.
"Golf courses usually get vilified for damaging the environment," Widder said, "but in this case they're the good guys."
Shane Wright, course superintendent at the country club, said his staff is "pretty judicious about what we do. Our course looks good and plays good, and I feel like we have it dialed in now in terms of the environmental practices."
Widder said Treasure Coast homeowners should follow the country club's example. Noting that her teams found grass clippings floating throughout the entire sample area, she said residents who live on the water and even blocks away should be aware that if they wash or blow clippings into storm sewers, fertilizers and chemicals will make their way into the marine ecosystem.
She said bagging, mulching or composting clippings is a better choice for the environment.
"A lot of the solutions are pretty simple," Widder said.
Widder said local ordinances limiting the use of fertilizers, especially during the rainy season, also help keep pollutants out of the lagoon.
"Those laws need to be in place all along the Indian River Lagoon," she said.
Widder also hopes ORCA's pollution mapping project can be in place throughout the lagoon and that one day the maps can be included on Google Earth.
"People need to know how unique the lagoon is," Widder said, "how the water used to run gin-clear and how there used to be massive amounts of fish in the water. With the murky water we have now, it's not the ecosystem it used to be."