The Board of Castile and León has activated a rescue operation de peces in the Tera River, at the height of Espejo de Tera (Soria), due to the low flow of these weeks. The intervention focuses on specimens trapped in isolated pools, where the lack of water renewal reduces the oxygen at critical levels. For this, they use specific techniques to prevent the mortality of fish fauna and ensure their survival.
Environmental agents from the Regional Government and wardens from the Urbión Game Reserve are participating in the operation , with the aim of preventing fish kills. The work has been planned to act quickly in the most critical areas and ensure the survival of all species present.
A low water level that tightens on the Tera River
The summer drought, exacerbated by high temperatures and a lack of rain , has left sections of the riverbed practically dry. This situation fragments the river into small, disconnected pools where dissolved oxygen levels plummet , turning the environment into a fish trap.
The phenomenon is recurrent every summer in the province of Soria, and the Tera River is once again experiencing its effects intensely. To reduce the impact, the Environmental Service is monitoring the area and evaluating similar interventions in other sections with flow problems.
How the rescue is executed step by step
The team uses a portable electrofishing device that emits a gentle, controlled shock. This stimulus momentarily stuns the fish, allowing them to be lured into nets for hand-caught without harming them. The team emphasizes that accuracy and caution are crucial to ensuring the fish's safety.
- Location of pools: Critical enclaves where there are isolated fish are identified.
- Application of mild current: Electrofishing stuns briefly and facilitates safe handling.
- Catching with landing nets: The specimens are collected one by one to avoid stress and injuries.
- Immediate stabilization: The fish are placed in tanks with a continuous supply of oxygen.
Transport and release in safe areas
Once captured, the specimens are transported in a continuously oxygenated water tank installed in the bed of a pickup truck belonging to the Regional Government of Castile and León. This system maintains optimal conditions during the journey, ensuring their well-being.
The release takes place in sections of the Tera River itself or, failing that, within its same watershed . Areas with guaranteed flow until the arrival of the autumn rains are chosen, minimizing stress and preventing translocations between different watersheds.
Coordination and surveillance in the province
The operation is being coordinated by the Soria Territorial Environmental Service , which is continuously monitoring the river network. Measures to protect wildlife are being evaluated in other rivers in the province showing similar signs of drought .
These types of rescues are repeated every summer, when the hydrology is most adverse. The combination of constant monitoring , appropriate technique, and controlled transport allows us to reduce the impact of the drought and preserve the natural heritage of the rivers in Soria.
From the coordination of agents and wardens in Espejo de Tera, a rapid and well-planned intervention is prioritized : detection of pools, electrofishing without harming the fish, transport in oxygenated tanks, and release in sections with stable flow. All of this forms a chain of actions that, coordinated by the Environment Department, prevent fish mortality and maintain the ecological function of the river until the flows recover.