Cyanobacterial toxins can harm fish populations even in the early stages of algal bloom development when humans cannot see it, not just during the peak of summer, new research from the University of Guelph has found.
“The data suggests we need to be tracking these blooms as early as spring,” announced post-doctoral researcher Dr. René Sahba Shahmohamadloo from the University of Guelph’s Department of Integrative Biology.
Shahmohamadloo led the study along with researchers from the Ontario Ministry of the Environment, Conservation and Parks. The work was recently published in Environmental Science & Technology.
The research team examined the negative impacts of algal blooms before the release of cyanotoxins — microcystins in particular — which are the most common toxin released by blooms.
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Adult and juvenile rainbow trout were exposed to two types of microcystin toxicity, intracellular and extracellular. Within 24 hours after exposure, the fish had buildups of the toxin in most tissues, with greater accumulation in the extracellular state, the study says. Within 96 hours, adverse health effects were measurable in all tissues and cancer-causing proteins were detected.
“We saw at the cellular level that cyanotoxins are causing these adverse health effects in fish,” said Shahmohamadloo in a statement from the University of Guelph. “The implications for that are substantial for governmental and non-governmental regulatory agencies that are trying to protect the public and also fisheries,” he added.
The toxicity exposure may not kill fish, the research team found, but noted that the health effects may be long-lasting.
Ultrasonics can provide a safe and cost effective solution to control cyanobacteria blooms in lagoons, reservoirs, small and mid-size lakes. Ultrasound has been demonstrated world-wide to be safe and effective at controlling blooms and eliminating toxic microcystins in water. Currently two sewage lagoons in Ontario are benefitting from the use of ultrasound. This low power, dual band, multi-frequency solution does not cause lysing of cells and thus does not release toxins while also controlling the bloom. In 4 weeks in one test, total blue-green algae count was reduced from 14 million to 3 millions cells/mL. Ongoing treatment reduce the concentrations much further.