July 17th 2019
Finally the clouds were gone and the sun was back again! What a glorious day to spend at anchor.
The only downside of high temperatures and slow running inland waters is the rapid accumulation of blue-green algae, also known as Cyanobacteria. These algae are rather peculiar. They are the only single cell entities that can produce oxygen. In the early years of our planet’s existence there was hardly any oxygen. There were only single cell life forms like this bacteria and some didn’t even need oxygen to exist. Then these Cyanobacteria started to produce large quantities of oxygen by means of photosynthesis, like plants. The organisms that didn’t need oxygen diminished, while the Cyanobacteria grew in numbers. The steadily growing numbers of Cyanobacteria produced more and more oxygen, eventually enabling more complex life forms like humans to see the light of day.
So although we probably thank our existence to these algae, they can also cause us quite a lot of harm. In slow running waterways or stagnant lakes their numbers grow explosively when the temperatures rise, and they start to ‘bloom’ which you can tell by the greenish smears in the water, a bit similar like swirls of green paint. These blooms can produce toxins that can cause serious illness when you swallow them by accident.
So despite the heat we didn’t fancy a swim, with al the blue-green swirls of algae all around us. Maybe this is a sign that we should move North…