Fish Friendly Technology

Work in Progress

Fish Friendly Turbines
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Fish Friendly By Pass

Other Fish Passage Routes

Work in Progress.


1. Fish bypass systems.

2. Fish friendly turbines.

3. Flow augmentation. 

4.  Habitat

5. Colverts


What is a PIT-Tag?
     A passive integrated transponder (PIT) tag is a microchip containing a unique electronic code and bonded to an antenna coil that is sealed in a glass cylinder.  Miniaturized PIT-tags, 2.1 mm in diameter and 12 mm long, were developed to monitor the migration of salmonids in the Columbia River Basin by implanting them in the body cavity.  When a PIT tag comes within range of an energized magnetic field created by an external detector antenna, it transmits a unique code to a receiving antenna so that the code can be recorded on a computer.  From 1987 to 1999, approximately 5 million PIT-tagged juvenile salmon have been released into the Columbia River Basin. (source—NMFS)  

  The Passive Integrated Transponder ( or PIT tag ), is a very small (12 mm by 2.1mm) glass tube containing an antenna and an integrated circuit chip. The tag is inserted into the juvenile fish's body cavity. The tag remains inactive inside the fish for its lifetime, until activated at a PIT-tag monitoring facility located at a dam. As the tag is read, data about that particular fish is fed into computers, for use in research studies. The migration of the PIT-tagged fish can be tracked through the river system as it passes through smolt monitoring facilities at various dams. Each PIT tag carries a unique code to enable identification of individual fish, so smaller sample sizes are needed to obtain good results. Also, juvenile fish can be detected as they move through the monitoring facility at a dam, and can be directed to the river or to a transport barge as needed for a particular study. One limitation is that, to read the PIT tags, the fish must pass within 18 centimeters— about seven inches—of the monitor.
PIT - tag Research on Snake River Salmon by the National Marine Fisheries Service: