Study Examines Fish Population of Rainbow River

Taking a trip to one of the Sunshine State's beautiful springs soon? If so, you may see a popular “sunny” fish while you're there.

Almost 40 percent of all fish found in the Rainbow River System were the Spotted Sunfish, according to a recent paper published in the scientific journal, Florida Scientist, and written by District's Kym Holzwart a senior environmental scientist with the Southwest Florida Water Management District.

The District contracted with the Florida Fish and Wildlife Conservation Commission (FWC) to conduct fish surveys of the Rainbow River, Kings Bay/Crystal River, Homosassa River, Chassahowitzka River and Weeki Wachee River systems every winter and summer from 2013 through 2019. The publication presents the results for the Rainbow River System.

During the five-year period, 37 different species of fish were collected from the Rainbow River System. The study helps biologists tell how any impact, whether natural or man-made, is affecting the spring's ecosystem and ecology.

Holzwart explained that changes in a fish’s population can be a good indicator of whether a restoration project has been effective. She said the diversity within the same river can be surprising.

"The habitat complexity; the submerged aquatic vegetation coverage, biomass, and diversity; and the water clarity are greater in the upper river as compared to the lower river, " Holzwart said.

Florida has one of the largest concentrations of springs in the world, and studies like this help protect these natural resources from threats. The threats that affect these ecosystems can be from human activities or more broad threats like climate change. To read the complete study, click below.