JACKSONVILLE, Fla. – The eighth annual State of the River Report on the lower St. Johns River Basin shows there are positive signs of the waterway's health improving, but reveal there are concerns over deterioration.
"Our study reveals some improvement in the river's health as well as the importance of continued monitoring of the river and its ecosystem, said Dr. Radha Pyati, chair and professor of chemistry at the University of North Florida.
The river researchers found improvement in the river's health due to lower levels of nitrogen and fecal coliform, which comes from runoff and leaking septic tanks. The city has been addressing the septic tank issue, by installing more sewer lines.
Other trends show improvement in turbidity and the drop in phosphorus levels in the estuarine and saltwater sections.
On the down side, many other indicators of health aren't improving or their status is unclear.
Algae is still a problem, as they are an invasive species. There is also concern about the increasing salinity levels further downstream.
"Submerged aquatic vegetation and wetlands, critical to other aquatic life, are highly vulnerable to salinity changes and they should be carefully monitored and better understood in the Lower St. Johns River," said Dr. Lucinda Sonnenberg, director of the Millar Wilson Laboratory for Chemical Research and research professor of chemistry at Jacksonville University.
One indicator that the river's health has deteriorated over the years is the increase in overall surface water discharges of toxic chemicals.
Some other unsatisfactory indicators include contaminated sediments, high levels of phytoplankton, including algal blooms with potentially harmful levels of cyanobacteria toxins, and fish consumption advisories due to mercury.
A presentation by Pyati and Sonnenberg on the findings will take place Friday at the opening session of the 2015 Environmental Symposium, titled, "City of Jacksonvill--50 Years of Environmental Stewardship," scheduled from 8 a.m. to 5 p.m. at the Adam W. Herbert University Center, Building 43, in the Grand Banquet Hall, Room 1044, on the UNF campus.