Popularly known as a fish ladder or fish way, the mechanism aims to ensure the free movement of aquatic life through a dam, especially fish that once freely traveled through the river.
The five methodologies used to monitor fish passage are:
1) Video image system with records of fish leaving the mechanism, on 24h, seven days a week.
2) Pit-tag monitoring (radiofrequency identification): small chip implanted in the fish that allows following its movement inside the channel.
3) Biotelemetry: data collection at a distance without cables, using a chip inserted in the fish, that emits radio and acoustic signal which are captured by antennas and hydrophones, generating information about the fish movement in the surroundings of the dam.
4) Capture of fish inside and downstream of the fish passage to identify selectivity, both in species and in size.
5) Hydraulic monitoring: evaluation of the channel’s main flow characteristics, which allows make relationships between fish behavior and hydraulic characteristics of the of fish passage. Here there is a rare and important interaction between engineering and biology, allowing verify if there are opportunities for improvements in the mechanism.
“Tractebel has participated of all steps of the Belo Monte fish passage, since the conceptual project until this monitoring phase. This is very important, because we have opportunity to complete the entire project’s cycle. Now, we are evaluating the premises and goals that we had in mind when we projected the fish way, to ensure that we met the expectations about its functioning”, says Raoni Rodrigues, coordinator of the Project for Implementation and Monitoring of the Fish Passage.
Two million individuals were counted in the first 360 hours of analyzed images from the video system. An outstanding number that surprises even the system monitoring team, since there are no previous records on this volume of fish being monitored.
Tractebel and Belo Monte HPP
Tractebel has been carrying out activities for the plant located in the state of Pará since 2007. The Latin America Tractebel team is present from the Environmental Impact Study and Report (EIA/RIMA) until coordination and implementation of environmental, biotic and physical plans, programs and projects.
Click here to watch a video about the fish transposition mechanism recently produced by Norte Energia, a consortium responsible for the construction and management of the Belo Monte HPP.