Assessment of Aerial Photointerpretation for Detecting Submersed Aquatic Vegetation

Submersed aquatic (underwater) vegetation is an important habitat component of the Upper Mississippi River System (UMRS). It provides cover, food, and spawning habitat for fish and invertebrates as well as food for waterfowl. Submersed aquatic vegetation also affects its immediate environment by acting as a nutrient source or sink, slowing velocity to allow suspended material to settle, and altering temperature, light penetration and dissolved substances in the surrounding water. In recent years, resource managers have perceived a decline in submersed aquatic vegetation in the UMRS. Long term trend data, collected over a broad spatial scale, is needed to substantiate or refute these perceptions.