Common bleak

The common bleak (Alburnus alburnus) is a species of freshwater fish belonging to the family Cyprinidae within the order Cypriniformes. While widely recognized as a component of European freshwater biodiversity, its uncontrolled presence can have negative consequences for managed aquatic systems and agricultural irrigation infrastructure.

In the context of aquaculture, the common bleak acts as a significant competitor for natural food resources. By feeding heavily on zooplankton and aquatic insects, it depletes the nutrient base required for the development of commercially valuable fish species, leading to reduced productivity and economic losses in stocked ponds.

The biology of the bleak is characterized by high reproductive rates and rapid maturation. Spawning occurs in installments throughout the spring and early summer. Because the species is highly adaptable to various water conditions, it quickly occupies irrigation channels and reservoirs, often reaching densities that become difficult to manage.

The impact of this species on agricultural water management is primarily related to physical obstruction. Massive schools of bleak frequently clog the intake screens and filtering systems of irrigation pumps. This mechanical interference causes pump downtime, technical failures, and disrupts the critical irrigation schedules for crops.

• Implementation of fine-mesh screens at water intake points.
• Deployment of acoustic deterrents to keep schools away from pumps.
• Predator-based control using carnivorous fish species.
• Regular manual harvesting and maintenance of water supply channels.