Periphyton on rocks

As part of our participation in the RSVL (Voluntary Lake Monitoring Network), during the summer, from 2013 to 2015, we monitored the periphyton (layer of algae and sediment on the rocks) at 20 sites distributed around Lac de l’Achigan. Monitoring will resume for 3 years from summer 2020.


Monitoring the periphyton would make it possible to assess the probability of degradation of the lake. In fact, as it is partly composed of algae, their growth, favored by the input of nutrients (phosphorus, nitrogen), would increase its thickness. Therefore, the thickness of the periphyton is an element that can be used to assess the probability of degradation of the lake. In this table provided by the MDDELCC, we can see that the 2013 monitoring results show an increase in the probabilities of degradation at Lac de l’Achigan.















The MDDELCC is working on the development of a monitoring results sheet as it does for transparency measures and water analyzes. As soon as they are available, we will present them to you.

References :

Ministry of Sustainable Development, Environment and Parks (MDDEP), Laurentian Regional Environment Council (CRE Laurentides) and Interuniversity Research Group in Limnology and Aquatic Environment (GRIL), 2012. Periphyton monitoring protocol , Quebec, MDDEP, Department for monitoring the state of the environment and CRE Laurentides, ISBN 978-2-550-62477-6 (PDF), 33 p.

Christine Roy, personal notes taken during the conference on aquatic plants of Dr Richard Carignan, Saint-Hippolyte, August 17, 2013.