Comparing the Effects of Artificial Habitat Structure and Natural Wood on Macroinvertebrate Communities and Largemouth Bass Growth

The addition of natural (e.g., coarse woody habitat; CWH) and artificial (e.g., plastic fish attractors) habitat is often used to enhance systems that have experienced declines in habitat availability. However, the mechanisms by which artificial habitat enhancement influences aquatic food webs remain understudied. We introduced artificial habitat structures or CWH 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. Overall, macroinvertebrate biomass did not differ between habitat types, but macroinvertebrate taxa richness and diversity were slightly higher on the artificial structures. Largemouth bass growth was not different between natural and artificial habitat structures. Although not specifically tested, field observations suggest macroinvertebrate communities were most influenced by the presence and amount of periphyton colonizing habitat structures. Our results indicate that habitat material itself may not be as important as providing a stable substrate for primary production and subsequent macroinvertebrate colonization.