Dr. Quinton White, executive director of Jacksonville University’s Marine Science Research Institute, spent time discussing the St. Johns River’s unique characteristics in the second installment of his monthly “River Life” column on Friday, Dec. 28, in The Florida Times-Union.
Here’s an excerpt:
It’s the combination of salt and fresh water that adds to the uniqueness of the St. Johns. Most of us know it flows north from the mountains of Florida. Except in Florida’s case, that is really the mid-Florida sand ridge, with a height of less than 30 feet. So the St. Johns drops only about 30 feet over its entire 310-mile length. That makes it a very slow-moving river.
A common misconception is that the St. Johns is one of only three rivers in the world to flow north, but there are actually dozens that do, with six in the U.S. Its small drop — and the fact the St. Johns is wholly contained in Florida — is also what makes our river special.
When the St. Johns meets the Atlantic Ocean, something very special happens: It becomes an estuary. This area, where the salt content is higher than fresh, but lower than sea water, is home to about 90 percent of the commercially important species we consume: oysters, shrimp, blue crabs and many species of fish.
It is the delicate balance of fresh and salt water that make estuaries like the St. Johns River so productive for seafood and so special for us to enjoy.
Read the entire article by clicking here.