Comparison of Water Resource Management Programs: An Algae Action Threshold Level Approach

摘要

Water resource management programs designed to control nuisance algal infestations have historically been dominated by reactive approaches. With increased regulatory scrutiny regarding algaecide use, data regarding efficacy of integrated management approaches are needed. This research outlines an efficient method of comparing management programs based upon exceeding designated algae action threshold levels (AATL) in pond systems. Phosphorus mitigating technologies were specifically evaluated as phosphorus had been indicated in supporting many nuisance algal types/densities. The objectives of this research were to evaluate pond management programs in terms of action thresholds exceeded, number of reactive algaecide treatments and algaecide amount required to maintain ponds below AATL. This research compared management programs consisting of: 1) Copper sulfate;2) SeClear Algaecide and Water Quality Enhancer;and 3) Phoslock phosphorus binding technology plus SeClear (as needed). Water and algae samples were analyzed every two weeks over two growing seasons on replicated research ponds and compared with designated AATL parameters. If an AATL was exceeded, then a reactive algaecide treatment was implemented for the corresponding water body. Ponds managed by copper sulfate alone exceeded a greater amount of AATL and required a significantly greater (P < 0.05) amount of reactive algaecide treatments to maintain control (average 6.5 annually) whereas SeClear and Phoslock plus ponds required 4.3 and 1.8 treatments, respectively. The average amount of copper applied to maintain ponds below AATL was 1414 g with copper sulfate whereas copper amendments were significantly decreased with SeClear (830 g) and even further with Phoslock plus management programs (342 g). Additionally, management programs incorporating nutrient mitigation required fewer treatments and less copper in year two of the program. This research provides valuable information for water resource managers to evaluate integrated approaches to water resource management in terms of social, economic, operational and regulatory viewpoints.