Weser and its springs and tributaries are originally considered home waters of large salmon populations. Due to the increasing water pollution, construction of hydraulic barriers and modification, i.e. destruction of salmon habitats, the large populations were reduced and died out during the 19th and 20th century.

A successful repopulation in the Weser river basin system is therefore the appropriate indicator for the ecological integrity of many habitats in a river system and their interconnection with marine habitats.

Since many years ago, the projects have been implemented by fishing associations and organizations and other interested parts, partly supported by government programs, in order to repopulate migratory fish. Strong motivation, voluntary engagement and financial input were invested with the aim to repopulate salmons and sea trouts in the waters of the Weser river catchment area, as well as to support the eel population.

In order to protect the eel, EU Member States have obliged themselves to undertake the necessary measures in terms of the fisheries policy in the framework of the EU Eel Regulation. As the first step towards this goal, it was decided to compile the so-called eel-management plans.

Since the long-distance transport and shipment of the animals between different states and river systems involve the risk of disease and epidemic spreading, the office of the River Basin Commission Weser has developed, in close cooperation with the Taskforce for Fish Disease Prevention of the Lower Saxony State Office for Consumer Protection and Food Safety (LAVES,) an Information brochure for the fish disease prevention.