Bodies of water where there is no strong water current have a tendency to fill in over time, due to siltation and plant growth. Over the course of centuries, lakes tend to become ponds and ponds tend to become wetlands. In the presence of [[eutrophication]], as when agricultural runoff carries fertilizer into lakes, plant growth is accelerated and the process can speed up dramatically. | Bodies of water where there is no strong water current have a tendency to fill in over time, due to siltation and plant growth. Over the course of centuries, lakes tend to become ponds and ponds tend to become wetlands. In the presence of [[eutrophication]], as when agricultural runoff carries fertilizer into lakes, plant growth is accelerated and the process can speed up dramatically. |