St. Johns River (Lower)

The St. Johns River (officially Saint Johns River, but commonly spelled St. John's River) is the longest river in the U.S. state of Florida, stretching 310 miles (500 km) from Indian River County to the Atlantic Ocean in Duval County. The St. Johns River is the second longest river in the United States that flows in a generally northwards direction. It was designated as one of the American Heritage Rivers in 1997.The elevation change from headwaters to mouth is only about 30 feet, making the St. Johns one of the world's "laziest" rivers. The Upper St. Johns Basin upstream of Lake Harney contains almost all of the river's elevation change. The river channel upstream of lake Harney is roughly 76 miles long including the open water bodies of Puzzle Lake, Lake Poinsett, Lake Winder, Lake Washington, Sawgrass Lake, and Lake Hellen Blazes. The final 25 miles of the basin to the southern border of Indian River County is marshland. Within the marsh is Blue Cypress Lake. The 190 miles of the River From Lake Harney to its mouth has no real gradient. It flows due to volume of fresh water discharged from its tributary streams. Its extremely low velocity, combined with the generally level elevation, causes the St. Johns to spread out to a great width for much of its course. During periods of low flow, the river can be influenced by tides as far south as Lake Monroe - 161 miles inland. For a distance of over twenty miles before arriving at downtown Jacksonville, the river's average width exceeds two miles, and in some places, exceeds three miles in width. The slow flow of the St. Johns makes it difficult for pollutants to be flushed from the waters, which has become a serious problem for the river ecosystem. Still, the river is home to numerous species of plants and animals. It is not uncommon to see dolphins in the river east of Jacksonville and manatees in the springtime when the water warms up. Alligators, bald eagles, ospreys, stingrays, and many species of fish—both salt and fresh water—are found living in the river and on its banks. The entire basin is managed by the St. Johns Water Management District. The lower (northern) basin begins where the largest tributary of the St. Johns, the Ocklawaha River, joins the flow. (Both rivers are part of the modern Caravelle Ranch Wildlife Management Area.) It passes through the historic city of Palatka, Florida, then through unspoiled riverine bottomland hardwoods, pine flatwoods and sandhill communities, on its way to Jacksonville. Past Green Cove Springs, the river becomes an estuary, where fresh and salt water meet, and a wide diversity of living species inhabit the islands, inlets, sounds, streams and marshes of the area. The St. Johns is known for excellent fishing, especially largemouth bass. Its estuarial nature provides both freshwater and saltwater or brackish-water species. Saltwater species include redfish, flounder, tarpon, and the brackish water sea trout, known locally as the "gator trout". A recent report states that saltwater species have been venturing farther up the river (southwards) in recent years. Some of the best known fishing occurs in January–March, when the American shad run up the river, and it becomes full of trolling boats. The shad, like the salmon, are anadromous and live most of their life at sea. They are caught primarily for the eggs, shad roe, for the flesh is below average and full of small bones.