Adam J. Kaeser

Characterizing the habitat of large, navigable rivers is difficult, yet this information is critically important to the conservation of a variety of resident aquatic species. We used low-cost sonar habitat mapping to map benthic substrates throughout nearly 1000 km of four Coastal Plain rivers in Georgia and to quantify the distribution of rocky substrates that may serve as potential spawning habitat for two imperiled sturgeon species, the shortnose sturgeon (Acipenser brevirostrum) and the Atlantic sturgeon (Acipenser oxyrinchus). Although we identified hard, rocky substrates in roughly...

A need exists within the natural resource community for an inexpensive and rapid technique for mapping and quantifying benthic habitat features of navigable river systems. Habitat mapping and assessment are critical components of research and management of aquatic fauna and the systems they inhabit. Unlike more expensive side scanning sonar units, the Humminbird side imaging system employs a transducer that can be mounted directly to the transom of a small boat thus enabling the survey of streams that include shallow, rocky areas. Our field experience with the Humminbird 981c has...