In 2020, an important fish mortality occured on the lake of Enghien les Bains, mainly caused by the development of cyanobacteria. In order to prevent for another disaster, the SIARE called on our savoir-faire to supply floating aerators and hydro-ejectors to maintain a sufficient level of oxygen into the lake.

Some information about cyanobacteria :

Cyanobacteria are toxic micro-organisms. When they proliferate, they use to release toxin having a negative impact on the fauna and human health. As they consume the oxygen present in water, they can be responsible for fish mortality due to anoxia.

Three main parameters can be responsible for the cyanobacteria development : luminosity, heat and nutriments. These three factors are easily reunited in the lac of Enghien les Bains.

Cyanobacteria can easily be identified, as they create a green lay on the surface of a pond.

Waters coming from different environments :

Supplied by different rivers, the water of the lake is not freshed during heat waves. Because of a stagnation of water, the environment conducived to the development of cyanobacteria.

During summer, an evaporation of water decreases the level of oxygen into the lake due to an increase of water temperatures.

Finally, some parameters – like the rainwater runoff or a wrong connection to the sewage systems – are responsible for an overflow of the organic loads and polluants into the lake that feed the cyanobacteria.

Our Flobull and Aquasub technologies to bring oxygen :

Following a study carried out by ID EAUX, the SIARE asked us to supply aerators to remedy to fish mortality and cyanobacteria.

A total of twelve machines were installed on the lake of Enghien les Bains to provide the oxygen necessary for the survival of aquacultural life, particularly during summer.

The Flobull surface aerator is one of the ranges selected. Installed in a number of six, each Flobull – with a power of 1.5 kW – contributes to the oxygenation of the lake by projecting a jet of water onto the air. The surface aerator helps to set water masses in motion while bringing oxygen to the pond.

Our hydro-ejector Aquasub is the other range selected for the lake of Enghien les Bains. Also installed in the number of six, – with a power of 1.5kW – Aquasub enables the brewing of water while injecting oxygen to the depths of the lake.

Each machine was settled in order to create several oxygenation zones into the lake to prevent for the fish mortality during heat waves.

Find out more information about the fight against cyanobacteria in the lake of Enghien les Bains directly in the dedicated article written by the SIARE : https://siare95.fr/siare-vous-informe/actualites/lutte-contre-les-cyanobacteries-au-lac-denghien-que-fait-le-siare.html