The researchers studied the relationship between nutrients and chlorophyll in the Rybinsk Reservoir. They found that the amount of chlorophyll in the water changed depending on the levels of nitrogen and phosphorus. The ratios of chlorophyll to phosphorus and nitrogen varied over time, with higher values indicating more nutrients in the water. These findings suggest that the amount of chlorophyll can help predict and control the growth of algae in the reservoir, especially in areas with high nutrient levels.