Fish Species Associated with Revetted and Natural Main Channel Border Habitats in Pool 24 of the Upper Mississippi River

Abstract

Two revetted and two natural main channel border sites within Pool 24 of the upper Mississippi River were electrofished over a 3-year period to determine the fish species and diversity of species associated with the two habitat types. Over the sampling period, 6,440 fish were collected of which 70% were taken from the revetted sites. One revetted site had larger diameter stones (≳ 2 feet) than the other; 40% of the fish collected were taken at the large-stone site. There were no differences in species numbers along the revetted and natural banks; each habitat produced 33 species. Thirty-eight species were taken collectively from all sites. Gizzard shad (Dorosoma cepedianum) and common carp (Cyprinus carpio) were the two most numerous species collected along both the revetted and natural shorelines; they accounted for 65% of the total number of fish caught. Catch per unit effort (C/F) for the four sites varied from 138 to 20 fish/h. The large-stone revetment area had a mean C/F of 98; C/F were 75, 53, and 28 for the small-stone revetment area and the two natural shorelines, respectively. Catches at the large-stone revetment station accounted for 52% of the total weight of fish collected and averaged 360 lb/month. The other revetment area averaged 144 lb/month and the two natural sites averaged 101 and 82 lb/month. Common carp accounted for 75% of the total catch weight. The revetment with loosely placed stones was superior to the one with smaller, tightly packed stones for providing habitat for more fish.