Letter: Bullards Bar Dam behind salmon decline
The depletion of salmon in the Yuba River dates from the filling of the new Bullards Bar Dam. Before the dam was built to more regulate the flow of the river and to supply electricity and irrigation water, the Yuba was a more rambunctious version of its current wimpy self. Excepting the extreme high-water years that caused the recent floods, the Yuba was allowed to show its teeth each year, scouring the growth of algae from the bed, leaving behind pristine beds of gravel for the salmon to spawn in.
Today, the water is at a more consistent level, allowing algae to build up. The algae prevents eggs from receiving the necessary oxygen to mature and hatch. The lower water temperature produced has also killed off all the northern strain of largemouth bass that used to be in the river and reduced a large run of American shad to a shadow of its former self. Also gone are large populations of bluegill and crayfish. They are replaced by trout and steelhead, plus their supporting insects in the lower river. Compared to the earlier runs of steelhead I witnessed while fishing in the river during my youth in the '50s and '60s, the current ones are less than impressive. Steelhead are also dependent on a healthy salmon crop.
The proposal to remove the two dams would accomplish little other than flooding the Yuba River with years of retained debris, and most importantly, the mercury used by the early miners that is surely lurking deep in the debris behind each dam.