Dead Fish Wash Up at Calaveras Lake Due to Low Oxygen Levels

SAN ANTONIO - A significant number of dead fish were discovered at Calaveras Lake on Tuesday morning, prompting concern among local residents and officials. The Texas Parks and Wildlife Department has attributed the fish kill to low oxygen levels in the water, a situation exacerbated by the current high temperatures. This phenomenon is not uncommon at the lake, occurring approximately once or twice each year. Meteorologist Chris Suchan explained that warm water holds less dissolved oxygen than cooler water, which is particularly problematic during the hot summer months. The high temperatures, coupled with nighttime conditions that prevent cooling, contribute to the depletion of oxygen levels in the lake. During the day, aquatic plants, algae, and bacteria produce oxygen through photosynthesis, but at night, they consume oxygen, further stressing fish populations. Suchan noted that fish often exhibit signs of distress, such as gulping for air near the surface, similar to minnows struggling in a confined space. While low oxygen levels are the primary cause of the recent fish kill, other factors may also play a role, including runoff from herbicides, poor water circulation, and the lake's depth. The fish species most affected by this incident include red drum and shad, highlighting the ecological challenges faced by Calaveras Lake during extreme weather conditions. Local authorities continue to monitor the situation as they assess the impact on the lake's ecosystem.