A weir used to collect sockeye salmon for a critical breeding program to restore the salmon run on the Cedar River twice was damaged this week by rock-throwing vandals.

The weir, basically a fence that directs the salmon to a trap, crosses the river at Cedar River Park, just under the Interstate 405 bridge.

Monday and again on Tuesday morning someone, possibly teens, threw or dropped rocks onto the weir, which is constructed with plastic pipe. Three of the pipes were damaged and then repaired, according to Gary Sprague with Seattle Public Utilities.

Also, there are reports of illegal fishing near the weir, possibly by snagging the salmon. Such reports are common as the sockeye and other salmon, including the threatened Chinook, return to spawn, according to an officer with the Washington Department of Fish and Wildlife.

Workers with Seattle Public Utilities and the state agency have begun the weeks-long process of collecting sockeye salmon for trucking to the sockeye hatchery at Landsburg. There, when the females are ready, their eggs will be stripped and then fertilized.

The young fish will then return in four years or so as adults.