Everglades Water Quality: Part 1
Florida, a state that depends on water—fresh, estuarine and marine—for its economy and cultural identity more than most other states is in a dire situation of its own making. Decades of water and natural-resource mismanagement, recently accelerated, are coming home to roost. In recent years, there have been harmful algal blooms (HABs) in the Caloosahatchee River, St. Lucie River, St. Johns River, Florida Bay, Indian River Lagoon, the Gulf Coast, and the Atlantic coast. Indeed, much of Florida’s estuarine waters have been impacted by HABs in recent years.
Whether naturally occurring or introduced, the organisms that cause HABs are fueled by human-introduced nutrients, greatly worsening the situation. A scientific study published in 2007, for example, found that red tide was 20-fold more abundant in coastal waters (where it encounters nutrient-laden runoff) than in offshore waters where red tide blooms originate. The study also found that red tide was 13-18-fold more abundant in recent years (1994-2002) than historically (1954-1963), and that the seasons in which red tide occurred had expanded from mostly in fall to now include fall, winter, and spring. In fact, the most recent red tide along Florida’s Gulf coast lasted for more than 18 months. The frequency, intensity, and spatial coverage of other HABs are also increasing. Moreover, the occurrence of plankton blooms in general, by species that aren’t classified as Harmful, is also increasing.
Similar crises are occurring throughout Florida. Because Everglades restoration has stalled, not enough freshwater flows from Lake Okeechobee into the Everglades and then into Florida Bay. In 2016, this lack of freshwater caused algae blooms, fish kills, and an extensive seagrass die-off in Florida Bay. The water not flowing into the Everglades is instead being discharged into the St. Lucie River and Caloosahatchee River, where it has caused a harmful algal bloom so toxic that human contact is dangerous. The nutrient-laden water flowing out of the Caloosahatchee River is also a likely source for enhancing red-tide blooms. A recurring harmful algal bloom in the Indian River Lagoon, caused by a “brown tide,” has been enhanced by high flows of nutrient-laden water from local sources, and has resulted in extensive seagrass die-offs and fish kills. In recent years the St. Johns River has experienced harmful algal blooms of its own. Even some of Florida’s famous freshwater springs are experiencing algae blooms. The list goes on.