March 04, 2011

Both sides of the story

My first week at GWL! A new nature project to start with and a new way for me to really get stuck into the day. After extensive instructions and an enthusiastic introduction, we were able to handle an optical microscope and prepare samples for screening.

Later on in the process, we will also work with an inverted microscope to count the cells of colonies of blue green algae species. An inverted microscope is useful for observing living cells and organisms in such a way that the lightsource and the condenser are on top, while the objectives and turret are levelled below the sample. In some cases it will be necessary and less time consuming to use a digital camera and computer applications, connected to the inverted microscope, to count the cells. Full speed ahead!

The microscope revealed to me a microcosmos that I did not really know about. I am amazed by all those wonderful forms of algae, as works of art: from green algae to exuberant blooms of various blue green algae, in science known as cyanobacteria - and still there is more yet to come.

Cyanobacteria from preserved samples were magnified by 10x, 20x or 40x to see the structures of the colonies of cells of each algae up-close. These colonies can be simple, consisting of only a few cells, or quite complex, as if cells are exploding in fireworks or winding sideways till you see no more! The differences between blue greens and green algae are not always as clear as you would expect them to be. You need to look for tiny details or develop a 'mind image' of what you are looking for. As a result, determination of genera, species and variations can be quite difficult.

Different kinds of algae on sediment (epipelic).
Only screening can determine what they really are.
De Nemer in Haaren, NL March 2006.

In a short period of time we try to become ‘experts’ in relation to the species we must learn to recognize: Microcystis, Woronichinia, Anabaena, Aphanizomenon and Planktothrix. These cyanobacteria can produce toxins like neurotoxins, cytotoxins, heptotoxins and dermatoxins. In short, we could get sick if we swim in a pool full of blue green algae or drink from it – like when you go for a swim and you get a mouthful of water in your stomach when splashing in. Fish and other organisms can even suffocate during an intense bloom of blue green algae. The algae take up almost all the oxygen in the water.

During an intense bloom of cyanobacteria,
other organisms and creatures in the water
can be effected by the lack of oxygen in 
their natural environment, and even die from it.

Despite the dark image related to human health and water quality, created over time, cyanobacteria belong in the water since ancient times. Cyanobacteria are found in fresh, brackish or salt water, all over the world, for billions of years and for many years to come. They can even survive in very extreme conditions, where no other organisms will survive, as in the hot springs of Yellowstone. Some cyanobacteria even share a symbiotic relationship with other organisms: they co-exist in such a manner that they can both benefit from the optimal conditions they are living in. Moreover, cyanobacteria produce oxygen through the process of photosynthesis. This means that cyanobacteria in full bloom have different side-effects:

1) in a positive manner for creating oxygen, so we and other creatures can breathe - at least above the water surface, and
2) in a more than inconvenient manner in relation to the nasty effects on human health and water quality, including the risk of suffocating organisms and creatures living in the water.

Both sides of the story!

Let's see what we encounter and when we get tired of all the many samples heading our way in late Spring and Summer! At least, I am intrigued by this whole new very tiny world through the microscopic looking glass.


Bijkerk R (2009) Blauwalgencursus voor zwemwateronderzoek, Koeman en Bijkerk BV Haren, Rapportnr. 2009-033, versie 16 april 2009.

Joosten AMT (2006) Flora of the blue green algae of the Netherlands - I The non-filamentous species of inland waters, KNNV Uitgeverij Utrecht.

Simons J, Lokhorst GM & Van Beem AP (1999) Benthische zoetwateralgen in Nederland, KNNV Uitgeverij Utrecht.

STOWA & Wageningen UR (2009) Blauwalgen: giftig groen - de biologie en risico's van cyanobacteriën, Watermozaïek Rapportnr. 2009-43.