Occurrence and dominance of Cylindrospermopsis raciborskii and dissolved cylindrospermopsin in urban reservoirs used for drinking water supply, South China

Abstract

The tropical cyanobacterium Cylindrospermopsis raciborskii is of particular concern for its invasive characteristics and production of the toxin cylindrospermopsin (CYN). The present study represents the first attempt to determine the distribution of C. raciborskii and CYN in tropical China. The presence of C. raciborskii and CYN, as well as the composition of phytoplankton, was determined from a total of 86 samples from 25 urban reservoirs for drinking water supply in Dongguan City of South China. The presence of C. raciborskii was observed in 21 of the 25 reservoirs and confirmed that this species has been widely distributed in the investigated reservoirs. C. raciborskii accounted for between 0.1 and 90.3 % of the total phytoplankton biomass and contributed to the majority of the phytoplankton in some reservoirs such as Tangkengbian and Xiagongyan. Its biomass was negatively correlated with NO3 (-)-N concentration and Secchi depth. Dissolved CYN was detected in more than one-half of the reservoirs with concentrations up to 8.25 μg L(-1), and it positively correlated with C. raciborskii biomass. Dissolved microcystins (MCs) were detected in 12 of the 25 reservoirs with a maximum concentration 1.99 μg L(-1). Our data strongly suggest that C. raciborskii and CYN could be important health hazards in urban reservoirs of South China and that more data are needed for further assessment.

The success of the cyanobacterium Cylindrospermopsis raciborskii in freshwaters is enhanced by the combined effects of light intensity and temperature

“…Results of the three ways ANOVA for differences in growth rate of each species (C. raciborskii and P. agardhii) under different treatments (light and temperature) and culture conditions (mono-and mixed cultures). and relative biovolume of C. raciborskii in our subtropical lake (Javier Lake) was similar to those from other subtropical lakes in Brazil (Tonetta et al, 2013), China (Lei et al, 2014) and Australia (Everson et al, 2011). The three temperate lakes in the dataset (Bnińskie and Bytyńskie, Poland; Alte Donau, Austria) were all shallow, polymictic, and eutrophic to hypereutrophic (Kokociński et al, 2010), but they differed markedly in their C. raciborksii biovolumes.…”

On the occurrence and toxicity of Cylindrospermopsis raciborskii in Poland

“…The toxin is actively released by intact cells to the extracellular environment (Preußel et al 2009), remaining relatively stable over a wide range of pH and temperature (Chiswell et al 1999); it can accumulate in the water column and has been found in sediments from approximately 4700 years ago (Waters 2016). CYN has been reported to be produced by C. raciborskii strains from Australia and New Zealand (Hawkins et al 1997;Wood and Stirling 2003), and Asia (Lei et al 2014). To date no European strain of C. raciborskii, including Polish strains, have been identified as either producers of CYN or possessors of genes involved in its biosynthesis (Antal et al 2011;Kokociński et al 2013;Rzymski et al 2017).…”

Phytoplankton assemblages in a complex system of interconnected reservoirs: the role of water transport in dispersal

“…To achieve this goal, complex systems of interconnected reservoirs have been established in the last three decades. Several studies investigated water quality issues in this area (Hu et al, 2013, Liu et al, 2013Lei et al, 2014;Wang et al, 2014) highlighting a common pattern of eutrophication with high phytoplankton biomass and a high frequency of cyanobacterial blooms.…”