The Segura River basin faces a significant environmental challenge due to the proliferation of non-native fauna, which is disrupting the natural balance of its waters. The situation has reached a point where the original biodiversity is seriously compromised, forcing the authorities to take urgent action to prevent irreversible damage to the water bodies.
To try and bring order to this biological mess, an initiative has been launched that seeks not only to monitor but also to take direct action on the ground. The goal is to improve current knowledge about where these species are hiding and how they are expanding, allowing management measures to adapt to the changing reality of the basin, which is quite complex due to the diversity of habitats it presents.
Investment and deadlines for the rescue of the river
The Segura River Basin Authority (CHS) has taken a proactive step by launching a tender for a specialized service to monitor these invasive animals. The budget allocated for these tasks is nearly €300.000 annually , specifically €299.692, demonstrating the importance given to protecting public water resources in this area of ​​Spain.
This contract will have an initial duration of twelve months, although it may be extended for another year if the river's needs require it. This is not an isolated action, but rather a sustained effort to comply with the guidelines of the River Basin Management Plan, which aims to achieve good ecological status for all inland waters.
The main targets: zebra mussels and crabs
Among the "most wanted" species identified by environmental technicians, the zebra mussel and the Asian clam occupy the top spots. These mollusks have an astonishing capacity for colonization and can lead to fishing restrictions for the zebra mussel , as well as displacing local species. Therefore, constant sampling of both larvae and adult specimens will be carried out in reservoirs and critical points of the river network.
But the problem doesn't end there, as crustaceans are also causing significant problems. The monitoring plan includes comprehensive tracking of the red swamp crayfish, the signal crayfish , and the increasingly prevalent blue crab. These species not only compete for food but also frequently alter the riverbed structure and affect the aquatic vegetation upon which other native animals depend.
Technological innovation for early detection
One of the major innovations of this program is the incorporation of environmental DNA techniques . This method allows for the detection of a species, such as the zebra mussel, simply by analyzing a water sample in which the animal has left its genetic trace, without needing to physically observe it. It is a fundamental tool for early detection, which is vital when it comes to halting an invasion before it becomes widespread.
In addition to molecular technology, traditional manual and mechanical removal methods will be maintained in areas where the invasion is already a tangible reality. Focus will also be placed on managing transverse obstacles in rivers, such as dams and weirs, to understand how these elements affect fish mobility and how they may be facilitating the spread of exotic species.
The situation in the Segura River basin reflects what is happening across much of the Mediterranean, where it is estimated that non-native fish species already represent an overwhelming majority in many stretches of the river. This effort by the administration seeks to reverse a dangerous trend through constant environmental monitoring and direct intervention, ensuring that aquatic ecosystems recover some of their lost balance and can better withstand the effects of human activity and climate change.
