The fish kill was likely caused by overpopulation, which led to oxygen depletion, waste buildup, and limited resources in the pond, all of which contributed to the death of the fish.When a fishpond is overly populated, it can lead to several problems that affect the fish's health and survival, including:1. Oxygen Depletion Too many fish in the pond consume a large amount of oxygen, leading to low oxygen levels in the water. Fish need oxygen to survive, and when levels drop too low, it can cause fish to suffocate and die.2. Waste Buildup Overpopulation leads to an increase in waste, including ammonia and other toxins produced by fish excretion. These harmful substances can accumulate in the water, poisoning the fish.3. Limited ResourcesWith too many fish, resources like food and space become scarce, causing malnutrition and stress, which weakens the fish and makes them more vulnerable to disease.4. Algal BloomsOverpopulation can also contribute to nutrient buildup, leading to excessive algae growth. When algae die and decompose, they further deplete oxygen levels, exacerbating the problem.The fish kill was likely caused by a combination of oxygen depletion, waste buildup, and resource limitations due to the overpopulation of the fishpond.