ARS | Publication request: WATER QUALITY OF SELECTED LAKES ASSOCIATED WITH BEEF CATTLE PASTURES IN CENTRAL FLORIDA

Submitted to: Florida Cattleman
Publication Type: Trade Journal
Publication Acceptance Date: December 31, 2002
Publication Date: January 2, 2003
Citation: Sigua, G.C., Williams, M.J., Coleman, S.W. 2003. Water quality of selected lakes associated with beef cattle pastures in central Florida. Florida Cattleman and Livestock Journal. 64(4):47-49.

Interpretive Summary: Forage-based livestock systems have been implicated as major contributors to deteriorating water quality, particularly for phosphorous in fertilizers and manures impacting surface and ground water quality. In this study water quality parameters were determined for three lakes associated with beef cattle pastures adjacent to or within a 10-mile radius from USDA-ARS, Subtropical Agric. Res. Station, Brooksville, FL. Water quality in all three lakes was rated with a Tropic State Index (TSI) of "good" (<59). The Florida TSI integrates different but related measures of lake productivity or potential productivity. The measures included in the calculation of TSI are water transparency, chlorophyll a, total nitrogen, and total phosphorus. Generally the greater the water transparency, the "clearer" water is considered. Chlorophyll a is the pigment that gives most plants, including aquatic algae, their green color. As a measure of water chemistry it provides an index of the abundance of algae in waters, i.e., the greater the concentration of chlorophyll a, the greater the quantity of algae. Phosphorus and nitrogen are the primary nutrients which regulate the growth of algae and aquatic plants in lakes. In most lakes, either nitrogen or phosphorus may at times limit the growth of algae, which can cause accelerated eutrophication of the lake.

Technical Abstract: Forage-based livestock systems have been implicated as major contributors to deteriorating water quality, particularly for phosphorous in fertilizers and manures impacting surface and ground water quality. The objective of this study was to look at historical water quality parameters in three lakes in the Withlacoochee River Basin(Lake Lindsey - Lat/Long: 283746/822159; Spring Lake - Lat/Long: 282935/821740; Bystre Lake - Lat/Long: 283237/821934) associated with beef cattle pastures adjacent to or within a 6 km radius from USDA-ARS, Subtropical Agric. Res. Station, Brooksville, FL. The parameters measured to develop tropic state index (TSI) included water transparency (Secchi depth), chlorophyll a (measurement of algae content), total nitrogen, and total phosphorus. Water quality in all three lakes had a TSI of "good"(TSI of 0-59). Measures of water chemistry made during the 1990s in Lake Lindsey were similar to what was found in the 1960s. Water in Spring Lake was considered clear (color < 10 units) with a medium hardness and low concentrations of total nitrogen and total phosphorus. Water in Bystre Lake was be characterized as moderately colored and medium hardness.