that with other hobbies I may never have had the opportunity to do so. It was on a recent expedition into the deepest country side, to a lake usually brimming with lively brown trout that I sat watching the swifts diving over the blue waters to catch insects. Hold up! blue waters on an inland lake.
Sure enough the water during the day had become more and more blue. My fishing mate and a twitcher that was feeding the birds gazed in amazement at the bright blue film building up on the windward shore of this huge water. I seemed to remember something about this phenomena happening at Rutland water a few years ago. When arrived home I fired up the old PC, its so old it thinks a gigabyte is a form of fast food. The web page for the environment agency was down. I did get some info from the Wessex Water site and from the NRM, which I found out later was a site in New Zealand.
The latter site gave details of the toxicity levels of the toxins and the effects from contact with the blue scum, I had a very restless night, it was scary stuff, what made it even worse was the wife kept  bursting into song with She Wore Blue Algae every five minutes.  The next day I was able to contact the environment agency the chap was really helpful and pointed out that this phenomena occurs all over the world and the toxins produced vary as to their potency and the location. It then dawned on me that the data I received from New Zealand might be just a little bit wrong for over here. So the old internet is guilty of over kill yet again.

As a koi keeper we think one of our greatest aggravations is blanket weed, it could be a lot worse. Algea comes in all colours and sizes, Red, Green. Blue .Brown as well as the stringy stuff we all know and love. The blue stuff, cyanophytes also known as cyanoprokaryotes  are unique because they can produce toxins some of the time, but not all sites produce toxins. Algae cells contain tiny gas vesicles allowing them to float to the surface or sink to the bottom in response to changing light and nutrient availability. When there is enough of them they can be seen in the water column and the water will take on a blue hue this is called a bloom.  If the conditions are right the cells will rise to the surface and form a film, wind or wave action will cause the film to concentrate at the windward shore and form a scum. It is contact with this concentrated layer that causes  problems. The toxin levels will be significantly magnified at this level. The scum can form a crust which can stay active for some weeks. As there is about a 50 % chance of a bloom being toxic it is better to assume all blooms are toxic. The affect of this on sensitive people will be a dermatitis rash on skin contact; it can cause allergic reaction in the form of swollen lips, itchy eyes, hay fever like rhinitis, so it would not be recommended to swim near it. Fur licking animals are at risk because they would ingest the toxins and that could have serious consequences. So keep animals away from the edges of water affected. Do not enter the water where there are concentrations. These are usually the windward shore, bearing in mind if the wind changes during the day  so will the affected area. If people are careful this phenomena presents no more risk than that of adders, and bee stings. It certainly wont stop me going fishing but I will be more aware in future.    

                 Roy French.....