Oxygen Depletion from Olive Mill Waste Blamed for Mass Fish Die-Off in Moroccan Dam

The various analyses carried out have revealed a low oxygen content of the dam’s impounded waters, with an average of 1.6 mg/l at the surface level, which concretely proves that the flow of olive mill waste is at the root of the fish deaths, the agency says in a statement cited by telquel.ma. These are the residues of the olive trees located upstream of the dam (which float on the surface) and which lead to a serious shortage of oxygen, and therefore, to the suffocation of the fish, the same source specifies.

Similarly, the analyses carried out by the committees set up in the aftermath of the incident did not reveal any source of pollution in the dam, except for the flows resulting from the waste from olive mill residues. Moreover, the analyses carried out by a public analysis laboratory before the incident "showed that the dam water is healthy".

In addition to these analyzes, the dead fish were also collected and buried with lime, in order to avoid the emission of bad odors or to pollute the ecosystem.