What typically causes fish kills in water bodies?

Fish kills in water bodies are often attributed to contaminants that are toxic to fish. Such contaminants can include various pollutants, such as heavy metals, pesticides, and industrial chemicals, which can disrupt fish physiology, lead to acute poisoning, and ultimately result in death. These toxins can enter aquatic systems through runoff, wastewater discharges, or atmospheric deposition, significantly impacting fish populations and aquatic ecosystems.

While other factors like excessive nutrients (which can lead to algal blooms) might create unfavorable conditions, the presence of acute toxic substances poses an immediate and lethal risk to fish. Fish kills caused by toxins can occur suddenly and result in large-scale mortality in affected areas, making this scenario particularly concerning for both biodiversity and the health of aquatic habitats.