Size, relative abundance, and catch-per-unit-effort of round goby, Neogobius melanostomus, in anthropogenically modified and natural habitats in the western basin of Lake Erie

Authors

  • E. A. Moran,

    Corresponding author
    1. The School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA
    • Department of Zoology, Ohio Wesleyan University, Delaware, OH, USA
    Search for more papers by this author
  • T. P. Simon

    Corresponding author
    1. The School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA
    2. The Franz Theodore Stone Laboratory, Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Put-in-Bay, OH, USA
    • Department of Zoology, Ohio Wesleyan University, Delaware, OH, USA
    Search for more papers by this author

Author's addresses: Erin A. Moran, The School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47405, USA.

E-mail: erimoran@indiana.edu

and

Thomas P. Simon, The School of Public and Environmental Affairs, Indiana University, Bloomington, IN 47405, USA.

E-mail: tsimon@indiana.edu

Summary

To determine if anthropogenically modified habitats possess greater numbers of round goby and serve as dispersal vectors, we used angling to compare catch-per-unit of effort for 64 natural and modified habitat areas. In addition, a gravel natural habitat was seined to compare length frequency distribution with anthropogenically modified habitats. Natural habitats included gravel beaches and natural rubble and cliff wall, while modified habitats included artificial riprap, concrete sea wall, and metal sheet piling. No significant difference in relative abundance was observed in round goby preference among modified habitats (P = 0.52), but natural gravel habitats were significantly different from modified habitats that included artificial riprap (P = 0.002), concrete sea wall (P < 0.001), and metal sheet piling (P = 0.003). When habitat subcategories were compared using anova, the natural gravel beach habitat was significantly different from the three artificial substrates and from natural rubble and cliff wall substrates (P < 0.004). No round goby were caught from gravel beach habitats; thus, this habitat was removed from further analysis. A Student t-test indicated no significant difference between habitats was found between the natural rubble and cliff wall habitat and the three other artificial habitats (concrete sea wall, P = 0.33; riprap, P = 0.53; metal sheet piling, P = 0.11). We further evaluated gravel beach habitats to determine the reason for the lack of goby capture. We seined gravel beach habitat and collected 328 individuals, with which we evaluated the length-frequency distribution and calculated length–weight relationships by sex. Our results indicated that only 5.2% of the goby population was available for capture by angling on the gravel beach habitat. A t-test comparing the demographic attributes between seining and angling indicated a significant difference between goby length (P < 0.001) and weight (P < 0.001). The regression slope indicated an ontogenetic habitat shift occurred near 62 mm standard length. Smaller round goby individuals were found in less structurally complex gravel beach habitat, while larger individuals were associated with complex habitat.

Ancillary