Claire Schelske and Patrick Brezonik
Lake Apopka prior to the late 1940s was well known as an outstanding sport fishing lake with exceptionally clear water (Clugston, 1963). With an original surface area of 18,000 ha, it was the second largest lake in Florida (Schneider and Little, 1973). However, draining the marshlands along the northern shore in the 1940s reduced the surface area to 12,500 ha. This shallow lake with an average depth of less than 2.0 m is located in Orange and Lake counties, 20 km west of Orlando. The change in water quality in this lake was reported to have been dramatic in 1947 (Clugston, 1963). At the time, the lake was characterized as having abundant rooted aquatic vegetation and very clear water until rooted aquatic plants were uprooted by a hurricane. A week after the hurricane the first plankton bloom was reported. Aquatic plants have never been reestablished. The lake is now a classic hypereutrophic lake, with chlorophyll concentrations that exceed 100 µg per liter, and has changed from a highly regarded sport fishing lake to a lake with few desirable sport fish.
According to Schneider and Little (1973), human influence on the lake was evident by 1920, when citrus groves were being planted in central Florida. The well-drained southern shoreline was an excellent site for groves, but the marshland on the northern shore was not developed. In 1920, the town of Winter Garden constructed a sewerage system and two large septic tanks, permitting waste products to enter the lake directly. Nutrients from municipal waste and runoff from the citrus groves seemed at first beneficial to a popular sport fishery. Grass beds that covered the lake bottom provided cover for young fish and tied-up nutrients. The marshlands were used as spawning grounds. Sport fishing for largemouth bass, speckled perch, bluegill, and other pan fish provided record-size fish and a half-million-dollar annual income for 13 fishing resorts and camps. A thriving commercial fishery yielded more than 3 million kilograms (dressed weight) of catfish in one 8-month period.
The lake was altered severely in the 1940s (Schneider and Little, 1973). A plan for draining and farming part of the marshland was formulated in 1942. This resulted in the construction of a dike along the north shore and draining of about 6,000 ha of fertile lake bottom so it could be used for muck farms. Thus, fertile muck land and availability of lake water enabled several crops to be grown and harvested each year. During dry periods, lake water could be used for