CyanoAlert – controversy over warning signs…

29 September 2011

Blue-green algae produce a multitude of toxins that are hazardous to both humans and animals.  Authorities are morally-obliged to post warnings at any waterbody that contains a bloom of these algae.  To not do so is arguably a criminal offence – despite the absence of any laws specifying this requirement.

In yesterday’s blog I discussed the problems faced by Zeekoevlei and the City of Cape Town’s reluctance to deal with the problem, a situation that has prevailed for decades now.  In Ohio, a decision to remove algal warning signs based on a calendar criterion has raised the ire of some. Then, in another questionable change, the state decided no longer to issue press releases when algae blooms are discovered. Officials said the information can be posted on the Web faster. Faster than sending the same notice in an email to the media? And how many people necessarily check the state’s website before a water outing? A notice on radio or television or in a newspaper would reach many people who have no idea the problem exists.

The Massachusetts State Department of Public Health has issued a public health advisory after finding a toxic algae in Lake Chauncy.   Cyanobacteria were recently detected in Lake Chauncy, causing the state public health officials to warn residents to avoid contact with the algae bloom, not to swallow the water and to rinse off after any contact.

In Canada, The North Bay Parry Sound District Health Unit wishes to advise that a bloom of blue-green algae has been detected on the northwest shore of Wasi Lake, in the area of Mallard Haven Road in the Township of Chisholm.  The report provides GPS coordinates for the bloom, something that anyone using the AlgaeTorch can provide automatically as the instrument logs the position and can upload it directly to Google Earth (search this blog for details of the AlgaeTorch).

People are getting all warm and fuzzy about the results of the alum treatment at Ohio’s  Grand Lake St Mary’s.  I must admit to overwhelming scepticism about such uncontrolled experiments which, at best, can only include the alum treatment as one possible factor leading to reduced algal development in a particular season – it being very difficult, if not impossible, to exclude any other factors.  Using alum is an expensive procedure that often produces short-lived results. Unless the alum is injected into the sediments properly and at a dose that meets the demand, its just an end-of-pipe treatment that will have to be repeated again and again.

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