Environmental tension in northern San Juan escalated this Tuesday with a formal complaint challenging the official version of the mass mortality of thousands of pejerrey fish in the Cuesta del Viento reservoir. Fishermen and locals discovered hundreds of dead fish on November 3rd. The government described the event as a «natural hypoxia» caused by organic matter accumulation and thermal variations. However, activist Saúl Zeballos from the 'Jáchal No Se Tocha' assembly presented technical evidence refuting this claim. He asserts it is not hypoxia but poisoning, accusing the Canadian mining company Barrick Gold, operating at the Veladero mine, of contamination. Zeballos is demanding urgent independent tests on water and sediment for heavy metals. This incident revives historical demands in an area 80% dependent on the Jáchal River for agriculture. Residents fear contamination could devastate their economies, already impacted by drought and climate crisis.