If you have been at Lake San Marcos this week, especially towards the dam, you have seen dead fish everywhere.
Most of these fish are bluegill, but there are a few bass, crappie, and catfish.
I was on the lake Monday morning and there were fish at the top sucking for air everywhere. Very sad to witness. I new many of them were doomed. The water looked dirty, a little milky, and had a slight rotten egg smell. When I returned Tuesday night, there were many dead fish along the shoreline mostly past the glamping sites towards the dam.
For every dead fish you see on the top floating, there are probably hundreds dead on the bottom. (DEAD FISH, for the most part, DON’T FLOAT!) Don’t be alarmed. This process is just the “fall lake turnover.” This goes on all over America in freshwater lakes. As the warmer water on the top cools because of the cooler fall nights, it becomes denser that the water at the bottom. The bottom water comes to the top and the top water goes to the bottom. The bottom water that has just surfaced has very little oxygen. Therefore, the fish use to living near the top, have a lot of trouble breathing. Thus, many of them dye.
Lake San Marcos has an abundance of bluegill. Bluegill eat the eggs of bass and crappie and are actually a nuisance fish. It is good that nature thins them out.
Nothing can be done about lakes turning over. You must just endure the smell and the poor fishing while the process in continuing. Depending on the weather it can take several weeks.
