July 02, 2011

Aquon - Institute for Water Research and Advice










GWL is no more. On July 1st 2011 four waterlaboratories of the Dutch Water Boards, including GWL, merged into Aquon - Institute for Water Research and Advice. Aquon provides its services primarily in line with the European Water Framework Directive. Clients include government organizations, mainly specialized in water policy and management. For more information, visit http://www.aquon.nl/ (only available in Dutch).

My participation on monitoring swimming waters and city pools for potential toxic cyanobacteria will continue in the new organizational structure. I will also continue with the course about freshwater phytoplankton.

Fixated sample of Aphanizomenon flos-aquae 

Additional information about the photographs:
Aphanizomenon flos-aquae (the brown-red string in the first photograph) belongs to the toxic cyanobacteria regularly found in Dutch swimming waters and city pools. This photograph was taken from a fixated sample in lugol (death sample). The filaments are not clustered anymore. The other organisms in the sample show diatoms, desmids, bacteria, green algae and other small cyanobacteria colonies. In fresh samples (living samples), the filaments are clustered almost like blades of grass, as seen in the second photograph

Live sample of Aphanizomenon flos-aquae


The microscopic photographs were taken with Nikon Inverted Microscope Eclipse Ti-U (110w), Nikon DS-Fi1 camera, NIS Elements BR 3.22.00 at 600x magnification oil and mastered in Photoshop Elements 8 (Photo 1), and with Olympus IX70, DP72 and cellSens Standard at 200x magnification oil (Photo 2). Photographs: Marta Demarteau/Aquon.