New insights towards the establishment of phycocyanin concentration thresholds considering species-specific variability of bloom-forming cyanobacteria
- 374 Downloads
In vivo phycocyanin (PC) fluorescence allows assessing cyanobacterial abundance in an easy, fast and cost-effective way. However, the establishment of PC thresholds is necessary for its use in routine monitoring programmes and there has been no consensus regarding their definition. This work aimed: (1) to assess the potential species-specific variation in fluorometric PC content among Microcystis aeruginosa, Nostoc muscorum and Cylindrospermopsis raciborskii; (2) to propose specific PC thresholds based on World Health Organization alert levels; and (3) to evaluate the in vivo PC signal reliability to interferences from massive algal growth and mixtures of bloom-forming cyanobacteria. Strong linear relationships were recorded between PC and cell counts, biovolume and chlorophyll a. However, a significant species-specific variation in PC was observed using cell counts. Increased microalgal densities did not cause significant interference of PC signals. Also, dual mixtures of cyanobacteria revealed strong relationships between measured and expected PC content. Results suggest that fluorometric PC is a good predictor for cyanobacterial biomass but cell number is not the best parameter to define thresholds. Biovolume should be used instead. Nevertheless, species-specific thresholds must be considered, rather than a general cyanobacterial threshold.
KeywordsCyanobacterial blooms Phycocyanin Fluorometry Monitoring Thresholds
This work was supported by European Funds through COMPETE and by National Funds through the Portuguese Science Foundation (FCT) within project PEst-C/MAR/LA0017/2013. Daniela de Figueiredo and Bruno B. Castro were also supported by FCT, by means of a post-doctoral Grant (SFRH/BPD/74184/2010) and a research contract (programme Ciência2008, co-funded by National Strategic Reference Framework 2007–2013 and European Social Fund), respectively. The authors thank Victor Galhano for providing one of the cyanobacterial cultures.
- APHA, 1999. Standard Methods for the Examination of Water and Wastewater. American Public Health Association, Washington, DC.Google Scholar
- Bowling, L., D. Ryan, J. Holliday & G. Honeyman, 2012. Evaluation of in situ fluorometry to determine cyanobacterial abundance in the Murray and Lower Darling Rivers, Australia. River Research and Applications 29: 1059–1071.Google Scholar
- Brient, L., M. Lengronne, E. Bertrand, D. Rolland, A. Sipel, D. Steinmann, I. Baudin, M. Legeas, B. Le Rouzic & B. Myriam, 2008. A phycocyanin probe as a tool for monitoring cyanobacteria in freshwater bodies. The Royal Society of Chemistry 10: 248–255.Google Scholar
- Codd, G., S. Azevedo, S. Bagchi, M. Burch, W. Carmichael, W. Harding, K. Kaya & H. Utkilen, 2005. CYANONET: A Global Network for Cyanobacterial Bloom and Toxin Risk Management. Initial Situation Assessment and Recommendations. International Hydrological Programme (IHP) of the United Nations Educational, Scientific and Cultural Organization (UNESCO), Paris: 1–5.Google Scholar
- Izydorczyk, K., C. Carpentier, J. Mrówczynski, A. Wagenvoort, T. Jurczak & M. Tarczynska, 2009. Establishment of an alert level framework for cyanobacteria in drinking water resources by using the algae online analyser for monitoring cyanobacterial chlorophyll a. Water Research 43: 989–996.CrossRefPubMedGoogle Scholar
- Lewitus, A. J., R. A. Horner, D. A. Caron, E. Garcia-Mendoza, B. M. Hickey, M. Hunter, D. D. Huppert, R. M. Kudela, G. W. Langlois, J. L. Largier, E. J. Lessard, R. RaLonde, J. E. Jack Rensel, P. G. Strutton, V. L. Trainer & J. F. Tweddle, 2012. Harmful algal blooms along the North American west coast region: history, trends, causes, and impacts. Harmful Algae 19: 133–159.CrossRefGoogle Scholar
- Marion, J. W., J. Lee, J. R. Wilkins, S. Lemeshow, C. Lee, E. J. Waletzko & T. J. Buckley, 2012. In vivo phycocyanin flourometry as a potential rapid screening tool for predicting elevated microcystin concentrations at eutrophic lakes. Environmental Science & Technology 46: 4523–4531.CrossRefGoogle Scholar
- Nichols, H. W., 1973. Handbook of Phycological Methods. Cambridge University Press, Cambridge.Google Scholar
- Vidal, L. & C. Kruk, 2008. Cylindrospermopsis raciborskii (Cyanobacteria) extends its distribution to latitude 34°53′S: taxonomical and ecological features in Uruguayan eutrophic lakes. Pan-American Journal of Aquatic Sciences 3: 142–151.Google Scholar
- WHO, 2003. Algae and cyanobacteria in fresh water guidelines for safe recreational water environments. World Health Organization, Geneva: 136–158.Google Scholar