Comparing the Effects of Artificial Habitat and Coarse Woody Habitat on Macroinvertebrate Communities and Largemouth Bass Growth

Lentic ecosystems are negatively affected by habitat degradation due to reservoir senescence and riparian zone development. The addition of coarse woody habitat (CWH) and artificial habitat (e.g., plastic fish attractors) is a popular management strategy used to enhance systems that have experienced declines in habitat availability. However, the mechanisms by which CWH and artificial habitat additions influence aquatic food webs remain understudied. We introduced either artificial habitat structures or CWH (Quercus alba) into ten 0.04-ha experimental ponds to test whether macroinvertebrate communities and largemouth bass growth differed between introduced habitats. The experiment ran for three months and structures were allowed to condition for one month prior to stocking juvenile largemouth bass. Macroinvertebrate communities were similar between habitat types. However, more taxa were found on the artificial structures and macroinvertebrate communities colonizing CWH appeared to increase relative to artificial habitat by the end of experiment. Largemouth bass growth did not differ between CWH and artificial habitat. Although not specifically tested, macroinvertebrate communities appeared to be influenced by the presence and amount of periphyton colonizing habitat structures. Our results indicate that habitat material itself was not as important as providing a stable substrate for primary production and subsequent macroinvertebrate colonization. Longer experiments may be necessary to determine the maximum influence of these habitats on primary and secondary productivity, particularly as CWH conditions.