title: Selective suppression of harmful cyanobacteria in an entire lake with hydrogen peroxide.
abstract: Although harmful cyanobacteria form a major threat to water quality, few methods exist for the rapid suppression of cyanobacterial blooms. Since laboratory studies indicated that cyanobacteria are more sensitive to hydrogen peroxide (H(2)O(2)) than eukaryotic phytoplankton, we tested the application of H(2)O(2) in natural waters. First, we exposed water samples from a recreational lake dominated by the toxic cyanobacterium Planktothrix agardhii to dilute H(2)O(2). This reduced the photosynthetic vitality by more than 70% within a few hours. Next, we installed experimental enclosures in the lake, which revealed that H(2)O(2) selectively killed the cyanobacteria without major impacts on eukaryotic phytoplankton, zooplankton, or macrofauna. Based on these tests, we introduced 2 mg L(-1) (60 μM) of H(2)O(2) homogeneously into the entire water volume of the lake with a special dispersal device, called the water harrow. The cyanobacterial population as well as the microcystin concentration collapsed by 99% within a few days. Eukaryotic phytoplankton (including green algae, cryptophytes, chrysophytes and diatoms), zooplankton and macrofauna remained largely unaffected. Following the treatment, cyanobacterial abundances remained low for 7 weeks. Based on these results, we propose the use of dilute H(2)O(2) for the selective elimination of harmful cyanobacteria from recreational lakes and drinking water reservoirs, especially when immediate action is urgent and/or cyanobacterial control by reduction of eutrophication is currently not feasible. A key advantage of this method is that the added H(2)O(2) degrades to water and oxygen within a few days, and thus leaves no long-term chemical traces in the environment.
authors: Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE Amsterdam, The Netherlands.
authors: Hans C P
authors: HC
authors: Matthijs
authors: Petra M
authors: PM
authors: Visser
authors: Bart
authors: B
authors: Reeze
authors: Jeroen
authors: J
authors: Meeuse
authors: Pieter C
authors: PC
authors: Slot
authors: Geert
authors: G
authors: Wijn
authors: Renée
authors: R
authors: Talens
authors: Jef
authors: J
authors: Huisman
mesh_terms: D000458:Cyanobacteria / Q000187:drug effects*; D005068:Eutrophication / Q000187:drug effects; D005618:Fresh Water / Q000382:microbiology; D006861:Hydrogen Peroxide / Q000627:therapeutic use*; D060106:Lakes / Q000382:microbiology*; D052998:Microcystins / Q000096:biosynthesis; D009426:Netherlands; D018508:Water Purification / Q000379:methods*; D060753:Water Quality
chemical_list: D052998:Microcystins; C078588:microcystin; D006861:Hydrogen Peroxide