Anyone With Experience With Blue Green Algae?

[J...]

Our local lake has been shut since November for an outbreak of BGA - Nodularia spumigena to be specific.

Recently they've reopened the lake - just before Australia Day weekend, quoting counts of 5000 to 10,000 cells/ml. Now they're saying that there is still the possibility that people could still get sick (bit late after they've had hundreds upon hundreds of people there on the weekend :D ).

I typically use this lake nearly every day for fitness work for my dogs over summer, given my other fitness options are pretty much out the window due to badly maintained council paths and tracks (too snakey!) and the heat. I've missed it something shocking and was keen to get back into working my dogs there but I'm having doubts about the counts still.

Does anyone happen to know what levels are "safe" - it should be safe given it's open for swimming and fishing but I have my doubts given they are saying people could still get sick. I'd love to be able to use it again but I'm not willing to put my dogs at risk.

Edited January 29, 2010 by Jess.

[Erny]

I don't know anything about Blue Green Algae other than it is not good - have no idea of 'safe' levels etc.

However, I'd be avoiding it until it is confirmed as being ok. I can only think it could be worse for dogs, as they often drink the water they're in. If it were me, I'd stay well clear for the time being. I can understand you missing it, all the same I think it would be safer to avoid it and something you are potentially less likely to regret.

Edited for spelling.

Edited January 30, 2010 by Erny

[all that glitters]

I had such a bad reaction to that stuff myself it made me sick as a dog both times I had it (then I figured out thats what made me so ill) - not that I am a dog, but yeah I have never felt so terrible in my life!

[J...]

The water is brackish so they don't drink it anyway. But yes as much I'd love to get back into that lake I have too many doubts, including how often they are testing it.

[OSoSwift]

I would avoid it until given the all clear. Dogs an people can get extremely sick from Blue/green algae.

Not worth the risk IMO

[persephone]

I would not be using it- esp. as the dogs will be there, right on the surface

[JaneyA]

Hi, I am an aquatic ecologist and teach ecology at university. 5 - 10,000 cells/mL is on the high side, depending on what species of cyanobacteria (blue-green algae) are there. Some are much more toxic than others, particularly if the dogs drink it, but the toxins secreted by some types of cyanobacteria can cause severe skin irritation just from contact.

Generally, direct contact to skin is to be avoided completely if algal levels exceed 15,000–20,000 cells/mL, again depending on the algal species.

The ANZECC guidelines for Fresh and Marine Water Quality for livestock drinking state "An increasing risk to livestock health is likely when cell counts of Microcystis exceed 11 500 cells/mL. There are insufficient data available to derive trigger values for other species of cyanobacteria" (Section 4.3.2.1).

So the levels in your lake are not over the limits, but I would keep the dogs out of the water until the cell counts reduce further. Unfortunately, high water temperatures, fertiliser runoff and other pollution, plus stagnant water/low inflows is the recipe for algal blooms

[J...]

Thanks Janey - that's what I was looking for.

Persephone - the water is clear, no sign of the sludge that's been on it for months. I was more worried about what I couldn't see.