Effects of nutrient reduction on the water quality and Largemouth Bass population in Lake Alice, Florida

• Published in: Florida scientist 2021-01, Vol.84 (1), p.1-20
• Main Authors: Schwartz, Marina K., Canfield, Daniel E., Cichra, Charles E.
• Format: Article
• Language: English
• Subjects: Aquatic sciences; Bass; Biological Sciences; Chlorophyll; Chlorophylls; Commercial fishing; Criteria; Effluent treatment; Effluents; Environmental protection; Eutrophic lakes; Eutrophication; Fish; Fisheries; Fishery sciences; Fishing; Freshwater fishes; Habitat improvement; Habitat loss; Introduced fish; Lakes; Long-term changes; Management; Mineral nutrients; Nutrient enrichment; Nutrient loss; Parameters; Survival; Trophic state; Wastewater treatment; Wastewater treatment plants; Water chemistry; Water pollution; Water quality; Water treatment
• ISSN: 0098-4590

Lake Alice, located on the University of Florida’s campus in Gainesville (FL), was sampled for water chemistry and Largemouth Bass (Micropterus salmoides [LMB]) by UF’s Introduction to Fishery Science class (IFS) annually from 1988 to 2020. Prior to November 1994, the lake received direct inputs of nutrient-rich, treated effluent from UF’s wastewater treatment plant. Effluent was completely removed by 1995, providing an opportunity for IFS to assess the long-term changes that occur in a single lake following point-source nutrient diversion. All water chemistry and fish data were mined from the class records kept by UF’s Program of Fisheries and Aquatic Sciences (Millhopper Complex in Gainesville, FL). Data were examined for immediate effects and long-term trends using a modified regression approach developed to provide statistically meaningful information. Following diversion of the treated wastewater, the commonly measured trophic state parameters (TP, TN, chlorophyll, And Secchi depth) underwent noticeable changes, but effluent removal did not significantly (p = 0.22) increase or decrease the estimated number of LMB in the lake. However, both K and Wr for LMB declined significantly over time as did PSS-Q and PSS-M. Information obtained at Lake Alice, when compared to that obtained from cross-lake Florida studies and from a major Florida sportfishing lake undergoing oligotrophication, demonstrate that fish parameters, especially those for LMB, need to be clearly defined when considering implementation of nutrient criteria. LMB can survive in eutrophic and hypereutrophic lakes and these lake types are some of Florida’s best fishing lakes. Thus, controlling nutrient inputs to lakes may not always be the best management strategy if the primary use of the lake is fishing. Fish habitat improvement provides an alternative management strategy to nutrient control. Eutrophication of Florida lakes is, therefore, most likely not a severe problem for Florida’s LMB fisheries unless nutrient enrichment directly results in habitat loss. Application of the Florida’s nutrient standards, numeric nutrient criteria, and management practices should reflect this reality.