Effects of Structural and Spatiotemporal Factors on Fish Use of Artificial Habitat in a Texas Reservoir

Abstract

AbstractWe evaluated fish use of artificial habitat in relation to structure size and shape and the spatiotemporal factors of season, diel period, and reservoir region in Striker Reservoir, Texas. Recycled Christmas trees were used to construct three sizes of cluster‐ and linear‐shaped structures; fish at each were sampled seasonally during the day and night with electrofishing. Largemouth Bass Micropterus salmoides and Bluegill Lepomis macrochirus comprised 57% of the fish collected; other centrarchids comprised an additional 33%. Overall fish assemblages at the habitat structures were not related to the factors we examined. However, species‐specific analyses indicated that the percentage of structures occupied, catch per unit effort (CPUE), and mean size of Largemouth Bass and Bluegills were influenced by the factors we examined. Largemouth Bass exhibited a greater percent occupancy of the largest structures and a higher CPUE in small structures; the mean size (TL) of Largemouth Bass was lower in cluster‐shaped structures at night. Bluegill percent occupancy and CPUE were significantly greater in cluster‐shaped structures than in linear‐shaped ones; however, larger individuals were more often found in linear‐shaped structures. Spatiotemporal differences in percent occupancy, CPUE, and mean TL were apparent, with greater abundance of both species during summer and fall and larger mean TL of Largemouth Bass during spring. The percentage of structures occupied by Largemouth Bass was significantly higher in the lower reservoir; however, mean TL was higher among structures in the upper reservoir. The percentage of structures occupied by Bluegills, as well as CPUE, was greater in the lower reservoir. Our results suggest that both the size and shape of artificial habitats, as well as spatiotemporal factors, should be considered when planning habitat enhancement efforts.Received September 4, 2013; accepted December 19, 2013