What happens to the oxygen levels in water during late spring or early summer?

During late spring and early summer, the oxygen levels in water typically decrease significantly due to a variety of biological and environmental factors. As water temperatures rise during these warmer months, the solubility of oxygen in water decreases, meaning that less oxygen is available for aquatic organisms.

Additionally, the increased growth of aquatic plants and algae during this period can lead to higher rates of photosynthesis during the day, momentarily boosting oxygen levels; however, at night, plants and algae (as well as all organisms) consume oxygen for respiration, contributing to a dramatic drop in oxygen levels. Furthermore, heightened decomposition of organic materials due to warmer temperatures increases the demand for oxygen by microorganisms. Therefore, the combination of temperature-induced changes in oxygen solubility, increased respiration rates at night, and higher organic matter decomposition contribute to a significant decrease in overall oxygen levels in the water during late spring and early summer.