algae are not prevented from floating in shallow rivers and lakes. Secondary pollution caused by toxic substances (e.g., algal toxins) released from decomposition also ensues. Nitrogen (N), phosphorus (P), and potassium (K) released from algal decay will return to the water body. Consequently, the root cause of eutrophication is not solved completely and blooms will continue to relapse (Pan et al. 2006; Zou et al. 2006).