The Success of Vegetation Enclosures in Enhancing Habitat for Fish and Invertebrates

Introduction of aquatic vegetation is commonly used to enhance habitat for a number of fish species.  Vegetation enhancement projects often do not evaluate the success or determine if planted vegetation is successful in increasing fish or prey densities.  In this study, three types of enclosures were compared in Lake Paradise (Coles County, Illinois) with five different species of vegetation (N = 22 to 123 cages for each).  The goal of the introductions were to increase vegetative habitat on a lake wide scale and ultimately enhance largemouth bass recruitment.  Fish and invertebrate densities were evaluated in each of the vegetation species and enclosure type combinations as well as non vegetated enclosures.  American pondweed had the greatest long-term survival of all species, followed by wild celery and sago pondweed.  Large cages (2 m diameter) were more effective than either dispersed small cages (1 m diameter) or clustered small cages and resulted in greater percent cover and total area of vegetation for all species.  We also observed greater densities of both fish and invertebrates in vegetated cages than in non vegetated cages.  Vegetated enclosures had greater abundance of Lepomid and Ictalurid species.  Enclosures were successful in establishing vegetation in Lake Paradise and future research will examine changes in lake wide implications for invertebrates and recruitment of largemouth bass and other fish species.