Just eight months ago, \u00a0Alcollar\u00edn\u00a0 dressed in gala. This small town in \u00a0C\u00e1ceres\u00a0, with just over 300 residents, was showcased at the \u00a0International Tourism Fair of Madrid\u00a0 as a privileged corner to observe birds, fish, or simply take a stroll beside its reservoir, a blue mirror nestled in the surrounding pasture. However, today, the picturesque postcard has turned into a nightmare.<\/p>\n
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Where water used to shimmer, a desolate muddy landscape now sprawls, marked by the presence of \u00a0dead fish\u00a0. The air is thick with a putrid smell, penetrating the streets of the town. Residents describe the situation as an \u201c\u00a0ecological disaster\u00a0\u201d and look on in disbelief toward the dam. Meanwhile, the \u00a0Guadiana Hydrographic Confederation\u00a0 (CHG) justifies the operation, claiming it was “of vital importance” for the future of the basin.<\/p>\n
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The Operation That Changed Everything<\/strong>. The Ministry for \u00a0Ecological Transition\u00a0, facilitated by the CHG, initiated a plan to eradicate the invasive species \u00a0Pseudorasbora Parva\u00a0\u2014commonly known as the \u00a0Chinese fish\u00a0 or \u00a0Gobio de Boca T\u00fape\u00a0\u2014which had been present in the reservoir and the Alcollar\u00edn River since 2010. This species is included in the Spanish catalog of invasive species and poses significant concerns for ecosystems within the EU, making its control not just recommended, but a legal obligation.<\/p>\n <\/p>\n The eradication plan involved months of observational studies using specialized vessels and concluded with a \u201c\u00a0controlled\u00a0\u201d emptying of the dam to facilitate the capture of fish. According to the CHG, the reservoir was at 100% capacity\u2014equivalent to 50 million cubic meters\u2014before the operation commenced. Yet, as reported by local news outlets, the emptying inadvertently released thousands of invasive specimens downstream, allowing the species to spread into the Ruecas and Guadiana rivers.<\/p>\n <\/p>\n The Enemy in the Waters of Alcollar\u00edn<\/strong>. The \u00a0Pseudorasbora Parva\u00a0 made its way to Europe around 1960 and has since expanded to over 30 countries, primarily due to aquaculture practices. First detected in Spain within the \u00a0Ebro basin\u00a0 in 2002, it has progressively colonized various regions, including Catalonia, Andalusia, Madrid, and Extremadura.<\/p>\n <\/p>\n In Alcollar\u00edn, the species emerged in 2010, and according to the \u00a0Ministry of Ecological Transition\u00a0, its \u00a0population density\u00a0 had reached a level that made total eradication technically challenging. Nevertheless, the CHG deemed it essential to mitigate its presence to prevent further distribution, particularly before planned connections with the \u00a0Orellana Canal\u00a0, and to ensure the reservoir\u2019s viability for irrigation and recreational use.<\/p>\n <\/p>\n Response to the Catastrophe<\/strong>. The contract for this operation, awarded in June 2024 to the engineering firm \u00a0SAU\u00a0, amounted to \u20ac787,861.99 (excluding taxes). It encompassed analyses of aquatic fauna, installation of containment barriers, extraction of native species, and controlled draining of the reservoir.<\/p>\n <\/p>\n However, reports from neighbors and environmental organizations like the \u00a0Fund for the Defense of Natural and Cultural Heritage of Extremadura (Fondenex)\u00a0 suggest the operation didn\u2019t unfold as intended. Thousands of invasive fish escaped downstream during the draining, compromising the original goals of the project.<\/p>\n <\/p>\n The sharp drop in water levels compounded by high temperatures led to the deaths of numerous native species, including the \u00a0vulnerable\u00a0 barbo. Shores were littered with decomposing fish, local aquatic birds abandoned the area, and the community\u2019s economy suffered devastating losses, particularly in terms of nature tourism.<\/p>\n <\/p>\n Conflicting Narratives<\/strong>. While the CHG defends the operation as necessary and safely executed, citing minimal mortality among \u00a0native species\u00a0, local organizations criticize it as an act of “ecological nonsense” that failed to consider the broader environmental context. They argue that the operation was conducted inappropriately, particularly given the time of year\u2014and have expressed intentions to file a complaint regarding the operation.<\/p>\n <\/p>\n Future Forecasts<\/strong>. Following the removal of \u00a0Pseudorasbora Parva\u00a0, the CHG plans to introduce native species again, in coordination with the \u00a0Extremadura Board\u00a0, and focus on maintaining barriers and controls to prevent future invasions.<\/p>\n <\/p>\n Yet, environmental organizations caution that the ecological and tourist recovery of the reservoir will take years, particularly since the invasive fish has now been documented in areas where it was previously absent.<\/p>\n <\/p>\n An Open Question<\/strong>. In Alcollar\u00edn, the divide between official reports and local sentiments is stark: to the administration, it\u2019s a necessary technical maneuver; for residents, it\u2019s an “environmental catastrophe” that has compounded existing challenges.<\/p>\n <\/p>\n Beyond this specific situation, the events raise a significant inquiry that transcends Extremadura: what are the environmental and social costs we are prepared to bear to combat a biological invasion, especially when full eradication proves nearly impossible?<\/p>\n <\/p>\n