The original condition of most bodies of water is oligotrophic. This term refers to bodies of water that are low in nutrients. In turn, submerged vegetation rooted in the soil can flourish. In natural ecosystems, like a forested ecosystem, nutrients are recycled in the soil, going from soil, to trees, to detritus, and back to the soil. Very little erosion or leeching of nutrients occurs.
Wetlands also aid in cleansing the water of nutrients.
In oligotrophic waters, nitrogen and phosphate levels are near zero. These bodies of water have a high recreational value and have a high production of fish and shellfish. As time passes, oligotrophic waters gain more nutrients and starts to change. Phytoplankton populations start to thrive and multiply. They make the water more turbid, and less light can penetrate and reach SAVs.