Zamyadi et al | http://dx.doi.org/10.5942/jawwa.2012.104.0114 Journal - American Water Works Association Peer-Reviewed E466 2012 © American Water Works Association Global climate change may have profound effects on water- shed runoff and phosphorus loads. affecting the ecological state of water bodies. In addition, potential water shortages from prolonged droughts and elevated water temperature (Jeppesen, 2009) may enhance the dominance of potentially toxic cyano- bacteria (CB) and their proliferation in drinking water sources (Jöhnk et al. 2008; Paul, 2008; Dale, 2006; Elliott et al, 2006). Infrequent sampling is conducted in most standard field moni- toring programs (Newcombe et al, 2010; Chorus et al, 1999), and the recommended frequencies miss many pollutant loading events (AWWA, 2010; Zamyadi et al, 2007) that occur on smaller time scales including CB proliferation. The rapid and more frequent field-monitoring of in vivo concentrations of CB is required to effectively manage risks associated with the pres- ence of toxic CB for recreational activities (Pilotto et al, 2008), drinking water production (McQuaid et al, 2011), and water reuse (McFarlane et al, 2008). Currently, the planktonic biomass is monitored by a combina- tion of laboratory methods, including chlorophyll a (Chla) mea- surement, microscopic counting, and taxonomic identification (Bastien et al, 2011; AWWA, 2010; Newcombe et al, 2010). Chla has been used for many years as an indicator of phytoplanktonic biomass and is not specific to CB; it is also present in eukaryotic algae. CB belong to the bacteria Monera and their reproduction procedure, cell structure, and biochemistry are different from eukaryotic algae (AWWA, 2010). Microscopic enumeration mea- surements provide information on the number of cells and their taxonomic distributions but may be subject to considerable sys- tematic and operator error, particularly when filaments or colo- nies are present (Ahn et al, 2007; Lawton et al, 1999). In addition to being error-prone, microscopic enumerations are tedious—sev- eral steps must be taken to prepare the samples, requiring special- ized equipment operated by experts (Ziegmann et al, 2010; Gregor et al, 2007). Other methods, such as continuous flow cytometry and high-resolution digital photometry, can be used for the task of counting and speciation of CB to the level of genus, and even of species (Daly et al, 2007). Real-time quantitative polymerase chain reaction (PCR) is also a promising technique (Fortin, 2010). However, these methods require skilled personnel and expensive instrumentation and are not yet rapid, cost-effec- tive online technologies. Online monitoring tools have been developed to estimate phy- toplanktonic biomass (including CB, chlorophyta, cryptophyta, and other algal groups). These tools are equipped with light- emitting diodes (LED) and use spectral signature differentiation algorithms to measure photosynthetic pigment’s fluorescence (Parésys et al, 2005; Wilhelm, 2003; Beutler et al, 2002). The aforementioned tools excite the accessory pigments and measure the resulting florescence. The excited pigments transfer photons to the Chla terminal receptor, which then emits a particular wavelength (florescence; Krause et al, 1991). More in-depth analysis of the spectral signatures makes it possible to distinguish The applications of in vivo probes that can detect the fluorescence of cyanobacterial phycocyanin are emerging and widely used for cyanobacterial detection in source waters. The objectives of this project were to study the sources of interferences involved with the readings of five probes (three commercially available probes and two prototype probes) using laboratory cultures and field samples. To compare the direct readings of different probes, the probe readings were presented in the form of a biovolume equivalent of cyanobacteria. Inorganic turbidity and the presence of algal biomass interfered with probe readings. A correction factor was developed for the cyanobacteria probes using simultaneous chlorophyll a measurements. The field data demonstrate that the potential underestimation of cyanobacterial biomass that corresponds to alert levels is a major issue with the application of in vivo probes. These alert levels are used to trigger monitoring and management actions. This study shows that the correlation between a probe’s reading and cell count is almost meaningless, and that the correlation to biovolume is a relevant option for management purposes. Results show that probe users should be fully aware of the sources of interferences when applying and interpreting the results. In addition, the authors offer a novel procedure that corrects for chlorophyll a interference. Cyanobacterial detection using in vivo fluorescence probes: Managing interferences for improved decision-making ARASH ZAMYADI, 1 NATASHA MCQUAID, 1 SARAH DORNER, 1 DAVID F. BIRD, 2 MIKE BURCH, 3 PETER BAKER, 3 PETER HOBSON, 3 AND MICHÈLE PRÉVOST 1 1 Civil, Mineral and Mining Engineering Department, École Polytechnique de Montréal, Montréal, Québec, Canada 2 Department of Biological Sciences, Université du Québec à Montréal, Montréal, Québec, Canada 3 Australian Water Quality Centre, South Australia Water Corporation, South Australia, Australia KEYWORDS: cyanobacteria, in vivo fluorescence, interference, phycocyanin probe, source management Read the Expanded Summary