By ruining our wetlands we are not only killing animals and plants, we are flooding our towns and polluting air. By straightening  and deepening rivers and lakes we have destroyed wetlands. Since the wetlands regulate water that flows in the river, the river becomes very vonerable to flooding and can flood towns, sometimes permanently. It also kills animals who live in the wetlands. The trees and plants in the wetlands clean the air, which means there will be alot more pollution in the area.