Lake San Carlos, a well-known natural space in Arizona, was the scene of a massive fish kill — which forced US authorities to order its immediate closure.
An unprecedented environmental catastrophe keeps the scientific community on alert, after it was confirmed that almost 100% aquatic fauna of Lake San Carlos, an emblematic place located in the United States, died suddenly.
The San Carlos Recreation and Wildlife Department o indefinite closure from space, following the discovery of a large number of decomposing specimens on the banks of this well-known Arizona reservoir.
Emergency services and several local reporters confirmed the seriousness of the situation, which was completely inaccessible to fishermen, says .
The presence of biological remains of thousands of largemouth bass, channel catfish and black sunperch created a serious health risk scenario. Apache reservation authorities, in coordination with the Bureau of Indian Affairs, are overseeing the affected area.
Although there is not yet an official, definitive publication in any scientific bulletin or magazine, the Arizona Game and Fish Commission is working with several biological hypothesesbased on similar disasters that occurred in the region.
Preliminary investigations suggest that the combination of a severe dry and the agriculture needs location will have accelerated this fatal outcome.
The hydraulic infrastructure associated with Coolidge Dam was designed primarily to supply the regional agricultural sector of the San Carlos Irrigation District and the Gila River Indian Community, leaving the sustainability of habitat in the background.
Coolidge Dam and San Carlos Reservoir are primarily used to provide water for agriculture in the region. In dry periodsthe release of water for irrigation drastically reduces the amount of water stored in the reservoir, which can come close to the so-called dead pool — the level at which water can no longer flow normally through the dam or is below the useful operational zone.
With less water available, fish are concentrated in an increasingly smaller volume. This greater density, combined with shallow waterhot and stagnant, reduces the dissolved oxygen that fish need to breathe.
The problem may worsen with excess nutrients from fertilizers, which favor algal blooms: during the day, these algae can produce oxygen, but during the night they consume itcausing sudden drops in oxygen levels and leading to fish asphyxiation.
Researchers are particularly concerned about call detection golden algaeor golden seaweedan invasive exotic variety that has recently colonized several aquatic ecosystems in the region, explains .
This plant microorganism has the ability to release potent biological toxins destructive, which dramatically compromise the essential respiratory functions of exposed fish.
The artificial basin collapsed in a similar way on at least 20 occasions since its construction in 1930, demonstrating the fragility of an ecosystem dependent on the demand for water for irrigation.
The San Carlos Recreation and Wildlife Department is now keeping close watch on the water’s chemical parameters with the goal of presenting a definitive conclusion on this tragic environmental episode.
