This video explains the nitrogen cycle and the important role oysters play in improving water quality. Dr. David Kimbro explains the nitrogen cycle. While naturally occurring nitrogen is necessary for all life to survive, an excess of the synthetic nutrients added to fertilizers can have a negative impact on water quality. Oyster filtration can remove excess nutrients from the water. Without the water filtration that oysters provide there would be a harmful increase in nutrients in the water, which would ultimately threaten the various animal species that rely on oysters for clean, livable water.