High pH and trout don’t mix. Learned via Sep Hendrickson’s California Sportmen radio show (via podcast) that the California DFG has instituted a “voluntary catch and keep” recommendation for Eagle Lake trout. The combination of hot weather and low-water conditions has elevated the pH of Eagle Lake, which is commonly in the 8.4 to 9 range, to more than 9.2. This flies in the face of the catch and release practice encouraged in many fisheries but has a basis in science.
Eagle Lake, near Susanville, Calif., is a natural lake reliant on snow melt from Lassen Nation Park’s Thousand Lakes area as well as springs. When the lake falls below 5,106 feet in elevation, thanks to our limited water supply this year, the pH rises with the water temperature. While Eagle Lake trout can live —— through stressed — in a pH of up to 9.8, above a pH of 9.2 it becomes a caustic solution can erode the mucous membranes covering the gills of the trout. Normally, this isn’t a problem. However, after a fight, gills in an eroded condition cannot transpire the gases and oxygen a trout requires to survive after a build up of lactic acid in its muscles. Without healthy mucous membranes, the capillaries in the gills can burst at an unseen microscopic level, virtually guaranteeing that a played out fish will die within 48 hours.