Restocking and study of genetic variability of native fish in the Upper Biobío

Within the framework of the environmental commitments acquired by the company during the environmental evaluation and approval of the Ralco Hydroelectric Power Plant project, the development of a Native Fish Repopulation Program and the execution of genetic variability studies of migratory populations were committed (period 2019 – 2022). In this context, in addition to the measures already implemented, a native fish reproduction project began in 2019 to develop a repopulation process in different stretches of the Biobío River. Likewise, it was planned to carry out a study of genetic variability of native fish, using a non-invasive method, based on the identification of small DNA fragments present in the environment (river).

In its first stage, the installation of cages for the collection of native fish populations was carried out in the Ecological Flow Zone of the Ralco Hydroelectric Power Plant together with the implementation of exclusion sections for the acclimatization of individuals and their reproduction.

During the first quarter of 2020, the first stage of fish restocking was carried out, from the cages and exclusion section to the ecological flow zone. In this repopulation stage, 47 specimens of the species Bullockia maldonadoi, 300 specimens of the species Percilia irwini and 100 specimens of the species Trichomycterus areolatus were released in the Ecological Flow Zone. Likewise, the genetic variability studies were carried out in the summer period of 2020.

During 2021 and 2022, with the population of native fish stable over time and prior agreement with the authority, the repopulation of native fish will be carried out in other points of the Biobío River.

The execution of the project allows:

• Fulfillment of environmental commitments by mitigating the impact of the project through the development of increasingly better environmental standards, through the implementation of innovative solutions.
• Increment of native fish species populations and, especially, the recovery of those in a state of conservation.