Sunday, June 22, 2008

The beautiful green toxic cyanobacterial pond scum at Madison's B.B. Clarke Beach

The Toxic Scum at B.B. Clarke Beach
Although many of Madison's beaches were open again by Sunday, B.B. Clarke Beach on Spaight Street was still most definitely closed. Not only had the recent flooding caused considerable beach erosion, but the high water still covers most of the beach that remains. And a bloom of toxic pond scum floats above the former beach, fed by runoff nutrients in the water.

The Toxic Art of CyanobacteriaCyanobacteria are great abstract painters. They're best known for the bright turquoise accent colors they use in compositions like this one (click through the photo to Flickr to view large). They look like specs of paint or bright little plastic fragments floating in the water, but they are really clumps of blue-green algae. They're bad news in a lot of ways, as this CDC site makes clear. Adults usually have the sense to steer clear of them (although boaters are warned to check first before getting into the water to launch their boats) -- but children and pets do not. It goes without saying you need to watch young children near water, but also be sure to keep your dogs away from the water if there is any chance it may harbor blue-green algae.

Update: Check below in the Comments for additional remarks left by some well-informed readers about blue-green algae that go into far more detail than my post about what they are, the problems they cause, how humans contribute to them and what can be done about them.


Compassionate Badger said...

you mean they are not letting people swim in that?!?!?


but what can be done to help control blue-green algae?

Anonymous said...

'Blue-green algae' is the commonly used (non-scientific) term for several types of bacteria (Cyanobacteria) that sometimes impart a blue-green tinge to water, both inland and marine. As in any war, three of the most common have been given nicknames by scientists, 'Anna', 'Fanny' and 'Mike'. For the moment, their real names don't concern us. They occur naturally in our waterways and are part of the water environment. They are extremely small organisms, their species only recognisable under a high-powered microscope; they may occur as single cells, or colonies of filaments, coils and 'clumps' of cells. When present in high concentrations, colonies of blue-green algae can often be seen with the naked eye: they may resemble fine nail or grass cuttings or take the form of small irregular bunches or pinhead-sized spheres.

In an open-water environment, they can form blue-green scums on the surface, now getting to be a regular feature of seaside, lakes, countryside and urban parks and gardens. This is their battlefront. A severe contamination will appear as a continuous 'mat' on the surface of the affected water and may extend some distance below it. When certain species in such high concentrations are decaying, the dying cells release their deadly toxins. They cause the water to taste bad and give off a malodorous smell, by releasing poisonous gas. They are harmful to the health of humans, as well as animals. (Those toxins of algae, which once dominated the recreational waters of Hampstead Heath, for example, are more virulent than the venom of the cobra).

In 1996, in a Brazilian hospital, over 50 dialysis patients died as a direct result of these toxins invading the public water system whose water was used for their treatment. Although no further human death has been recorded as directly attributable to blue-green algae until 2003, when a young boy died after swimming in a blue-green algae contaminated Milwaukee golf course pond, there are now many documented reports of acute and chronic human illnesses. But the main occurrence of human illness caused by these cyanobacteria still comes from the ingestion of contaminated drinking water. Similarly, throughout the world, significant animal and fish losses have been caused by toxic blue-green algae. Currently, in the UK, an increasing number of dogs are suffering because of ingesting blue-green algae after swimming in contaminated waters.

Questions have been asked in the EEC about the possibility of these toxins entering the water supply, but no steps have yet been taken in the UK, to include them in Water Regulations, which would make them, statutorily, part of water analysis protocols. One, microcystin, has a guideline 'threshold' published by the World Health Organisation.

cattapus said...

Managing blooms and their expansion

Starvation of the enemy is our best weapon! Algae need three things for optimal growth: light, nutrients and high temperatures. Lowering the nutrients, light and temperature available to the blue-green algae in the water supply will help reduce algal growth. The speed at which water is flowing and mixing is important in controlling light, temperature and nutrient availability to algal cells.
1. Water flow through the water system must be improved. In dry periods, flush with clean chlorine-free water. The normal incoming water will be loaded with nutrients. Filter beds of vigorous marginal plants must be planted at the point of inflow. (Phragmites communis is very effective for larger ponds).

2. More oxygenating plants must be grown, essential in the war against algae. (e.g. Lagarosiphon major - Goldfish Weed or Pondweed). They absorb carbon dioxide and mineral nutrients; they compete with and eventually starve out the enemy, blue-green algae.

3. Use floating plants for light control - up to 1/3rd the surface area of the water. This will reduce the light available to the algae. .

4. Surround waters with a vegetation buffer. Bushes and other plants use up and reduce the troublesome nutrients percolating through the soil to the pond.

5. Initiate water treatment measures BEFORE blooms start.

6. Use the "Barley Straw" treatment in the correct, specified, manner.

7. Real-time in-house analysis of water quality parameters by affordable computer process should be used to provide indicators for risk assessment. The affordable computerised systems now available should prove more economically viable compared with consultant or laboratory costs. Could be based centrally, to facilitate use by others, or on site locally.

8. Set up Voluntary water monitoring groups to monitor inland fresh waters on a regular, systematic basis. (The Secchi disc, turgidity, pH tests, water temperature, weather details.). Many inland waters already have associated voluntary groups, which could be utilised. Any necessary skills could quickly be learned and the necessary equipment is cheap. In North America, almost the whole of that vast country's inland fresh waters are monitored in this way! See

9. If blooms do occur, harvest them (remove them to compost).

10. Re-assess the practice/methods/extent of 'mudding out' of waters that inevitably causes severe ecological damage by removing entirely or severely reducing long established microbial organisms and plants that, by competing with the blue-green algae for nutrients and light, naturally reduce the probability of blooms occurring.

11. Avoid run-off into ponds from fertilizers, pesticides and eroding soil.

12. Most chemicals work to prevent an algal bloom. Water in small ponds can be protected from blue-green algae by dosing with gypsum and alum. These chemicals work by removing phosphorus from the water. In the UK. Algicides can NEVER be used to treat public waters because they may be harmful to the environment and the practice may be illegal.

Arrangements for the management of algal blooms should be documented and published in a local "Blue-green Algae Monitoring and Action Plan". It should include provision for assessing the nature and intensity of algal blooms.
Another difficulty, however, lies in the fact that algae can tolerate adverse conditions such as the complete drying of a pond or cold winter temperatures, and germinate new juvenile filaments when favourable conditions return. They form spores (akinetes), which are induced by cold, drought, lack of phosphate, and low light with lack of nutrients.
Yet another is that algae create aerosols and are airborne in significant numbers at certain seasons.

Madison Guy said...

Thanks for the marvelously detailed and informed comments in response to Compassionate Badger's question. I'm putting up an update on the post for readers who don't go to the comments.

Compassionate Badger said...

I agree with Madison Guy--Thanks A LOT! My questions have been answered.


Joslyn said...

I have a weird and random question. I am 26 years old, and when I was about 15 I went to a church camp where we swam in this large pond. It smelled funny and I didn't want to but they made us to go out on this boat to pass a "swim" test. It seems I really haven't felt good sence then. When I got home I had awful stomach issues and white cirles all over my tounge.. that was the start of it all. I have no been dignosed with an immune disorder where I do not produce white blood cells because "something attacked them all" the list goes on of the medical promblems as I get older because my white count is at 1.2 and the highest it goes is 1.5.... the doctors just say I have some radom diaease "they hope I grow out of" I know have Chronic Fatigue Sydrome, IC, IBS the list is growing... The last time I felt good was way back when... before i swam in that pond.... Reading this artical I am wondering if anyone knows any relationships to chronic illness and pond water. There was a lot of build up on one side of the pond and we weren't "allowed to go to that side" so I am wondering if I got exposed to something and if anyone eles has ever experinced this. the doctors seem to give up on me, so I have to start my own research. Any information about pond water and diseases is greatly apperiated. Feel free to even email me Joslyn from Ohio, USA

yavicto said...

Thank you so much for all the well-written info about algae blooms, especially to Cattapus. I'm writing from Lake Atitlan, Guatemala, the formerly most beautiful lake in the world, which was overcome by a stinky massive cyanobacteria bloom in October. Time magazine had an article about it.
We understand the basics, and it's a long road ahead. We really need to find out the "Barley Straw" treatment & how to do it in the correct, specified, manner--and/or any other methods that involve biomimicry, or have worked in semi tropical or large lakes. Lake Atitlan is 50 square miles surface, and 300 meters deep (?), with about 200,000 mostly indigenous Guatemalans living around it and depending on it in one way or another, including some for drinking water.
Anyone know of sites to look up specifics on how far from a lakeshore to plant banana trees, and willow (also said to be good for cleaning) ??
You can learn more about the cyanobacteria and the lake at
or look up "todos por el lago" and their newsletters.
Thanks to Madison guy for his great page and photos-the algae blooms here are not pretty at All. (but when photographed from above show a form that looks just like a spiral galaxy)