In your article on suction dredge gold mining regulations in rivers ("Golden Rules," March 3), new 49'er James Buchal made an ugly and untrue statement when he called cold-water refugia an "idiotic theory" of Native American tribes.
Refugia are not a theory. I have more than 10 years of professional salmon biology experience in northern California and can tell you that main stem river temperatures at tributary confluences are significantly cooler than most of the river from late spring into the fall. Any recreational swimmer will notice this. Cooler water contains higher dissolved oxygen concentrations and is crucial to the survival of juvenile salmonids.
Buchal continued by saying that fish are "happy" about food stirred up during dredging. While fish will certainly take advantage of unnaturally provided meals, this short-term benefit to a few individuals is a long-term detriment to their population. Dredging resorts in substrates in which specific runs of salmon have evolved to spawn.
Also, the most irresponsible of miners will dredge spawning areas while eggs are incubating. A few fish may be "happy" to get a meal, but meanwhile thousands perish.
Steelhead Steve, Arcata