The 10th annual State of the River Report, an analysis of the health of the Lower St. Johns River Basin by by JU and other researchers, reveals several areas of improvement but shows trends that some indicators have worsened, suggesting that continued monitoring and research of the river are needed.
Trends from the latest report show not only lower nitrogen and phosphorus levels but also dissolved oxygen levels in the mainstream are improving. Conditions for three critical wildlife species—the bald eagle, wood stork and Florida manatee—have also improved.
“Our summary of 10-year findings shows long-term drops in both nitrogen and phosphorus, which is good news about an important indicator that regional organizations have worked to improve. But algal blooms, which come from high nitrogen and phosphorus, haven’t decreased yet,” said Dr. Radha Pyati, chair and professor of chemistry at the University of North Florida.
Other indicators remain largely unchanged. For example, chlorophyll a, an indicator of harmful algal blooms, hasn’t decreased in the 10-year timeframe and shows no indication of decreasing soon. Fecal coliform levels remain significantly above water quality criteria in many tributaries, while submerged aquatic vegetation has experienced some regrowth due to rainfall, but the long-term trend is uncertain. Most finfish and invertebrate species aren’t in danger of overfishing, with the exception of channel and white catfish, which both have the potential to be overfished in the near future.
Although there are some positive and unchanged indicators, there remains some concerns for the river’s health. Over the last two decades, salinity has gradually risen and is expected to continue its increase, with growing potential negative impacts on submerged aquatic vegetation and the aquatic life that depends upon it.
“Salinity continues to increase from a variety of factors, some of which are natural and some caused by human actions. Ever since the river has been modified by humans, particularly by digging it deeper and removing fresh water, the increase in salinity has been exacerbated,” said Dr. Gerry Pinto, associate research scientist at the Jacksonville University Marine Science Research Institute. “The cumulative effects of increasing salinity stress the system, creating unfavorable conditions for habitat and what it supports. Of particular concern in this regard are the grass beds that prefer to grow in fresher conditions and provide food for manatees and shelter for juvenile fish.”
Another concern the report highlights is that nonnative species have also increased from 56 total species in 2008 to 80 this year. Of special concern is the spread of lionfish and Cuban tree frogs due to their impacts on the native ecosystem. Additionally, wetlands continue to be lost due to development pressures.
This year’s report contains a section on the bottlenose dolphin in the lower St. Johns River Basin and describes dolphin residence in the river and threats to its health, including a 2010 federally-designated unusual mortality event.
A presentation by Pyati and Pinto on the findings will take place Wednesday, Oct. 4, at the opening session of the 2017 Environmental Symposium, “Achieving and Empowering a Sustainable Community and Thriving Economy,” 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. The River Report and a brochure, a quick reference guide on river health and ways the public can help the river, will be available at www.sjrreport.com as well.
The annual symposium, sponsored by the Environmental Protection Board of the City of Jacksonville and the UNF Environmental Center, brings together members of the community to interact with the regular agencies responsible for developing and implementing environmental policy.
The State of the River Report is a collaboration among UNF, JU, Florida Southern College and Valdosta State University, and is supported by the Environmental Protection Board. UNF River Report team members include Pyati and Dr. Brian Zoellner, associate professor and Graduate Program director. JU team members include Pinto; Dr. Nisse Goldberg, associate professor of biology/marine science and chair of Biology and Marine Science; Dr. Anthony Ouellette, professor of Biology; and Dr. Gretchen Bielmyer-Fraser, assistant professor of chemistry. Dr. An-Phong Le, assistant professor of chemistry, Florida Southern College, and Dr. Peter Bacopoulos, a private engineer, complete the team.
The Marine Science Research Institute at Jacksonville University is the premier biological and environmental research and education facility on the St. Johns River. The two-story, 32,000-square-foot “certified-green” building has classrooms, laboratories, offices for the St. Johns Riverkeeper and the Florida Fish and Wildlife Conservation Commission, and areas for teaching Duval County public school students. For more information, visit www.ju.edu/msri.
The mission of the UNF Environmental Center, founded in 2004, is to establish, develop and support cross-disciplinary education and research related to the environment. The center fosters programs for students, faculty and staff to pursue environmental activities through academics, research and extracurricular activities. For more information, visit http://www.unf.edu/ecenter/.