Fish are well studied in Iowa, and there is a large amount of information available. The Iowa GAP Analysis project, http://www.gis.iastate.edu/gap/ is a project that is a cooperative effort of several agencies (mostly governmental). This project seeks to map and compile information about all of the vertebrate species in Iowa, and they have produced an excellent web site called the Iowa Aquatic Gap Fish Atlas: http://maps.gis.iastate.edu/iris/fishatlas/ This web site lists 157 species of fish found in Iowa and shows range maps and photographs of all of them.

Unfortunately, from a biological diversity standpoint fish are not doing all that well. And it is not really surprising. If we don't drain a wetland or waterway we usually put a dam on it to increase the water level. We have been very careless about letting pollution into the water ways.

I am not aware of any amateurs working with native fishes from a biological diversity standpoint (i.e., non-game wildlife) in Iowa, but there may be some.