| Florida’s springs provide countless environmental, recreational, and cultural benefits. Over the years, people who live near springs and visit springs have seen their springs degrade, either by the loss of historical discharge or prolific algal growth and the decreased biological diversity that apparently stem from water quality and quantity problems. The degradation of water quality in the Floridan aquifer appears to be related to another change in many Florida springs. Spring openings (or vents) and their receiving waters are experiencing ecological imbalances, as evidenced by the profuse growth of algae and/or invasive aquatic vascular plants, such as hydrilla. Biological studies now document excessive algal growth at many major springs. In some of the more extreme examples, such as Silver Springs and Weeki Wachee Springs, algal mat accumulations are several feet thick. Most scientists agree that elevated nutrient levels in the water are at least partly to blame. Nitrogen is considered the main chemical indicator of nutrient enrichment of springs, and nitrate levels have climbed steadily in many of the springs that have been sampled over the decades. The nitrate found in ground water and spring water has been found by isotope analysis to be from inorganic sources such as synthetic fertilizer, or organic sources such as human wastewater or animal manure, or a combination of the two. An ongoing objective is to establish a nutrient threshold or index that correlates the water column concentrations of nutrients with biological effects. |
