The study looked at how different levels of phosphorus in water affect the amount of chlorophyll in three types of underwater plants. They found that one plant, Najas guadalupensis, had less chlorophyll when there was only a little phosphorus in the water, while Ceratophyllum demersum and Myriophyllum spicatum needed more phosphorus to see a decrease in chlorophyll. This shows that different plants absorb phosphorus in different ways depending on how much is in the water.