Empirical study of cyanobacterial toxicity along a trophic gradient of lakes

Giani, Alessandra; Bird, David F.; Prairie, Yves T.; Lawrence, James F.

doi:10.1139/f05-124

Cited by 96 publications

(66 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…responded positively to increasing phosphorus levels between 0.1 and 0.4 mg phosphorus L -1 and Hee-Mock et al (2000) who showed that phosphorus was an important factor in the control of both the production of microcystin and the type of microcystin produced and that the reduction of phosphorus in eutrophic waters may lower the growth and microcystin producing rate of M. aeruginosa, resulting in reduction of toxic bloom formation. In a recent study of 22 lakes in southern Quebec, Canada, Giani et al (2005) observed stronger responses of toxin concentration to nitrogen content than to TP, which is in concurent to the results of this study.…”

Section: Toxicitysupporting

confidence: 92%

Use of PCR based technologies for risk assessment of a winter cyanobacterial bloom in Lake Midmar, South Africa

Oberholster¹,

Botha²

2007

Afr. J. Biotechnol.

View full text Add to dashboard Cite

Toxic freshwater cyanobacterial blooms are potential health hazards in water supply reservoirs and therefore predicting bloom events is an important goal of monitoring fresh water programmes. The recent identification of the mcy genes in the production of microcystin synthetase for the first time provides an avenue to study microcystin production at a genetic level. This paper reports analysis of a winter cyanobacterial bloom by use of quantitative real-time PCR, ELISA and PP2A methods for detection of strains present and determination of their toxigenicity in Lake Midmar South Africa. We further investigated the taxonomic composition of phytoplankton at different sampling sites and the physical and chemical changes caused in the surface water of Lake Midmar by waterfowl. Our study clearly demonstrates that the interaction between low surface water temperatures and productivity was overshadowed by the response to nutrients and nutrient availability. We also confirmed the presence of the toxic cyanobacterial strains through the use of molecular markers that detect the presence of some of the mcy genes in the mcy gene cluster that is able to synthesize microcystin toxins in Microcystis spp.

show abstract

Section: Toxicitysupporting

confidence: 92%

Use of PCR based technologies for risk assessment of a winter cyanobacterial bloom in Lake Midmar, South Africa

Oberholster¹,

Botha²

2007

Afr. J. Biotechnol.

View full text Add to dashboard Cite

show abstract

“…In contrast to western Canada, MC research in central or eastern Canada is either limited or in its infancy. Giani et al (2005) were identified in blooms collected from Hamilton Harbour, including MCRR, MCYR and MCLR (Murphy et al 2003). Concentrations as high as 400 µg/L were measured at the peak of the blooms.…”

Section: Geographic Distribution Of Microcystinmentioning

confidence: 99%

Cyanobacterial toxins in Canadian freshwaters: A review

Kotak¹,

Zurawell²

2007

Lake and Reservoir Management

View full text Add to dashboard Cite

Kotak, B.G. and R.W. Zurawell. 2007. Cyanobacterial toxins in Canadian freshwaters: A review. Lake and Reserv. Manage. 23:109-122.Cyanobacterial toxins are a serious water quality concern in productive water bodies worldwide. Microcystins (MCs), which are hepatotoxins, are prevalent in Canadian freshwaters while the occurrence of neurotoxins anatoxin-a, anatoxin-a(s) and saxitoxin appears to be much less common. Concentrations of microcystin-LR (MCLR), presumed to be the most common of the more than 70 MC analogues, are highly variable in phytoplankton assemblages of lakes and greatly influenced by phytoplankton species composition. The frequency of occurrence and concentrations of MC in lakes in western Canada tend to increase with lake trophic status as well as decreasing N:P ratio. Microcystins accumulate in the aquatic food web through feeding activities of invertebrates (i.e., filter-feeding by clams and grazing by zooplankton and gastropods). Eventual trophic transfer of MC to fish, and resulting mortalities have been documented. Human health may also be at risk. Conventional water treatment may adequately remove low MC concentrations from source water, but can fail to completely remove MCs when initial concentrations are high. To address human health concerns, Health Canada established a drinking water guideline of 1.5 µg/L of MCLR. More recently, it has been suggested that β-N-methylamino-L-alanine (BMAA), a non-protein amino acid produced by many species of cyanobacteria, may cause neuro-degenerative disease, thus representing a significant emerging health issue.

show abstract

“…Cylindrospermopsis raciborskii blooms reported in Marola Lake are another evidence of its eutrophic condition, once cyanobacteria blooms generally occur parallel to nutrient enrichment (Watson et al 1997). Due to the water quality deterioration resulting from cyanobacteria growth, freshwater researchers and managers are trying to identify their major causes (Giani et al 2005;Wagner & Adrian 2009) and this became part of our goal in this study.…”

Section: Discussionmentioning

confidence: 99%

“…Other common response to eutrophication is the change in the community structure by the selection of certain morphological or physiological types (Vinebrooke et al 2004). The result is often the dominance of species or groups favored by these modified environmental conditions, such as mixotrophic flagellates and cyanobacteria (Watson et al 1997;Giani et al 2005;Soares et al 2013). Cyanobacteria, or blue-green algae, can be especially dangerous due to their potential toxicity to humans and animals (Carmichael et al 2001).…”

Section: Introductionmentioning

confidence: 99%

The necessity of management in a lake of the Atlantic Forest biodiversity hotspot: nitrogen levels connected to a persistent bloom of Cylindrospermopsis raciborskii

2016

View full text Add to dashboard Cite

Conservational studies of the threatened Atlantic Forest biome are frequently restricted to terrestrial ecosystems. We know little about the water bodies, specially considering that this biome covers the third largest system of lakes in Brazil. Some of these lakes are located inside the protected "Rio Doce State Park", but many others are found outside this reserve. Th ese external lakes are seldom studied, but understanding their response to human activities is essential for the conservation and the protection of the lakes inside the Park. We evaluated the eff ects of degradation in a lake outside the Park, which shows a constant bloom of the toxic invasive cyanobacteria Cylindrospermopsis raciborskii. Phytoplankton, climate and physico-chemical variables were assessed from 2011 to 2013 to evaluate which were the major determinants of the lake dynamics. Despite the seasonal changes, the lake was always eutrophic, and cyanobacteria, transparency and nutrients were the major indicators of water characteristics. Th e lake seems to be nitrogen-limited and cyanobacteria were negatively correlated with nitrogen levels, since the constantly dominant C. raciborskii is a superior competitor for N. We suggest that the monitoring of nitrogen levels is fundamental to establish management strategies to avoid harmful algae blooms in this Atlantic Forest lake.

show abstract

Empirical study of cyanobacterial toxicity along a trophic gradient of lakes

Cited by 96 publications

References 53 publications

Use of PCR based technologies for risk assessment of a winter cyanobacterial bloom in Lake Midmar, South Africa

Use of PCR based technologies for risk assessment of a winter cyanobacterial bloom in Lake Midmar, South Africa

Cyanobacterial toxins in Canadian freshwaters: A review

The necessity of management in a lake of the Atlantic Forest biodiversity hotspot: nitrogen levels connected to a persistent bloom of Cylindrospermopsis raciborskii

Contact Info

Product

Resources

About