Distribution and Habitat Associations of Topeka Shiners in West-Central Iowa

The Topeka shiner Notropis topeka is a federally listed endangered species found in west-central Iowa.  Little is known about the distribution and abundance of this species since it inhabits small streams and off-channel habitats (e.g., oxbows) that are not commonly sampled by most fisheries scientists. There is also very little known about the biotic and abiotic factors associated with the occurrence and abundance of this species in Iowa.  Habitat and fish sampling was performed in 2010 and will continue in 2011 for both instream and off-channel habitats.  All fish sampled were identified and counted.  Depletion estimates were conducted for Topeka shiners in off-channel habitats where abundance was typically higher than instream reaches. Topeka shiners were present in 16 of 42 sites sampled in 2010.  However, 14 of the 16 sites with Topeka shiners were off-channel habitats.  All Topeka shiner sites contained orangespotted sunfish Lepomis humilis or green sunfish Lepomis cyanellus, of which Topeka shiners are thought to be nest associates.  Contrary to the findings of many others, Topeka shiners were sympatric with many predator species, such as largemouth bass Micropterus salmoides and northern pike Esox lucius.  As restoration efforts continue in Iowa, it is vital that we understand the distribution and habitat associations of these fish to ensure that recovery goals are met.