|Tweedale, Wendy - ST. JOHNS RIVER WATER MGT|
Submitted to: Aquatic Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 12, 2002
Publication Date: February 24, 2004
Citation: Sigua, G.C., Tweedale, W.A. 2004. Assessing redesigned effectiveness of the water quality monitoring program in the Indian River Lagoon, Florida. Aquatic Conservation: Marsh Freshwater Ecosystem 14:49-64. Interpretive Summary: In 1996, the long-term water quality monitoring network (WQMN) program in the Indian River Lagoon (IRL) of the St. Johns River Water Management District (SJRWMD) was redesigned to eliminate statistically redundant sampling and satisfy modeling requirements. Laboratory analysis was also centralized to eliminate inter-laboratory variability. The redesign strategy also included elements to determine previously unknown quantities such as differences in water quality parameters with depth, and over a short time period (day/tidal cycle). Because of reduced number of sites sampled, another result of the modifications was a substantial long-term cost savings. Staff and laboratory resources were used more effectively with lesser budgetary pressures on every participating government and private agency. The ultimate benefit would be a more cost-effective and efficient monitoring tool to gauge the water quality of the seagrass environment. Results further supported the view of a well-mixed condition at the sampling stations on most days.
Technical Abstract: By streamlining the IRL-WQMN, staff and laboratory resources were used more effectively and placed less budgetary demand on the participating agencies. The ultimate benefit was a more cost- effective and efficient monitoring tool to measure the water quality of the seagrass environment. Statistical analysis of the data shows that most water quality parameters that were measured were significantly different between stations, as expected by the redesign model. Statistical significance in water quality parameters with depth varied with parameter and daily conditions. Significance in sampling over a short timeframe (day/tidal cycle) also varied with parameter and daily conditions. Reduction of sampling sites from 150 to 24 resulted in a significant improvement of standard deviation (t-test; p = 0.05) for all water quality parameters analyzed. The improvement in the analyses of central tendency for data collected prior to 1996 and the years (1996-2000) that the redesign effort was in effect has demonstrated a more cost-effective and efficient monitoring tool to measure the water quality of the seagrass environment. We have learned that by refocusing and streamlining the water quality monitoring program within the context of its mission would enable conversion of data into meaningful information regarding the interrelationship among water quality, photosynthetically active radiation (PAR), and seagrass PAR requirements.