Coming clearing the surroundings of the pond of the Auberge, at the Bec-Thomas, about thirty kilometers northwest of Évreux (Eure) A landscaper had the other Friday (May 30) the unpleasant surprise of attending a macabre show. Near the shore, several hundred putrefied carp floated on the surface.
The advanced decomposition of the carcasses indicated that the fish had died for at least eight days. No one had noticed earlier because the place is little frequented. The area on which the pond is private and its owner lies in the Paris region. What could have happened so that so many fish can be killed at the same time?
A week later, it is still not easy to answer this question precisely according to Luc Tison, head of service of the French Biodiversity Office in the department of Eure. “There was a brutal episode, perhaps a polluting flow linked to nitrates from agriculture, a significant increase in water temperature or a lack of oxygen at a given moment. »»
A lack of punctual oxygen?
“I would look for this last hypothesis, but I cannot say it,” said the specialist. “The event was finished when I went there on May 30 because I was able to observe living carp which presented no signs of distress. They did not blow, that is to say that they did not seek oxygen on the surface. »»
What is certain is that the maintenance of aquatic life is more and more delicate in this pond. Covering an area of about 1.5 ha, it is very invassed, shallow and invaded with algae. “Even if carp are resistant fish, these conditions become harsh,” diagnoses Luc Tison.
“In this context,” he adds, “it is possible that overcrowding of fish has also played an aggravating factor role. It is a phenomenon that we have already observed. Some worried comments on the health and ecological consequences of this episode have flowered on social networks. Through a basketry system, the pond communicates with an tributary of the Seine, the Ileon, which crosses the Eure and the Seine-Maritime.
The estate is for sale
The mayor of the Bec-Thomas (200 inhabitants) wants to be reassuring: “There is no concern to have. We have two very reactive agencies, the French Biodiversity Office and the DDTM (Departmental Directorate of Territories and the Sea), which have taken the necessary measures to avoid an episode of pollution, “explains Jean-Luc Flambard.
One of the main precautionary measures will be to quickly evacuate corpses. The DDTM reminded the owner that this burden was in the shortest time. Another reason should encourage him to quickly erase all traces of this massacre: the estate is for sale!
