About 7,500 young chinook salmon were "photonically" taggedby high-school students this month in the first large-scale application of this technique in California. The students' efforts, coordinated by UC Davis Bodega Marine Laboratory researchers and New West Technologies, launched field testing of a new "light-triggered" tag. Easy to apply and to read as well as being economical, the tag is a solution of latex beads containing dyes that react to high-energy light. The solution is shot into the fins of fish using a specially adapted vaccination gun. "Ultimate success of the photonic tag could revolutionize the way we manage all our hatchery-produced fish so they do not compete with wild fish stocks," says Paul Siri, assistant director of the Bodega Marine Laboratory. The next big step is the June 2 transfer of the tagged fish from a hatchery in Petaluma to the National Marine Fisheries Lab at Tiburon, for further growth and monitoring by the Tyee Club. This work is part of Bodega laboratory's ongoing research on the salmon runs in California, which includes maintaining broodstocks and following the population genetics of declining runs.