No effect of round goby Neogobius melanostomus colonisation on young-of-the-year fish density or microhabitat use
The round goby Neogobius melanostomus has recently invaded several major freshwater systems in Europe and North America. Despite numerous studies predicting an impact on native fish assemblages, few have attempted to demonstrate it. In this case study, we monitored the effect of N. melanostomus colonisation on abundance and habitat utilisation of both young-of-the-year (YOY) native fish and YOY western tubenose goby Proterorhinus semilunaris in a typical, medium-sized European river. Colonisation by N. melanostomus had no apparent effect on either native fish abundance and species richness or P. semilunaris abundance. Moreover, after colonisation, both native fish and P. semilunaris occupied similar niches (i.e. microhabitats) to those occupied before colonisation. While niche use of YOY N. melanostomus and P. semilunaris overlapped significantly, YOY native fish utilised different habitats from the gobiids. We suggest that N. melanostomus did not compete for resources with YOY fish in our study area due to lack of niche overlap and/or surplus resources. As N. melanostomus rapidly dominated the fish assemblage at our site, we further suggest that utilisation of an empty niche, rather than competitive superiority, was the main factor facilitating its success.
KeywordsInvasive species Niche shift Neogobius melanostomus Proterorhinus semilunaris Impact
This study was supported by the Grant Agency of the Czech Republic, Grant No. P505/11/1768. We thank Gabriela Konečná, Markéta Mrkvová, Luděk Šlapanský and Lucie Všetičková for help with fieldwork, and M. Reichard for valuable comments to an earlier version of the manuscript. We are much indebted to representatives of the Moravian Angling Union for allowing us to sample in their waters.
- Grenouillet G, Hugueny B, Carrel GA, Olivier JM, Pont D (2001) Large-scale synchrony and inter-annual variability in roach recruitment in the Rhone River: the relative role of climatic factors and density-dependent processes. Freshw Biol 46:11–26. doi: 10.1046/j.1365-2427.2001.00637.x CrossRefGoogle Scholar
- Lederer AM, Janssen J, Reed T, Wolf A (2008) Impacts of the Introduced round goby (Apollonia melanostoma) on dreissenids (Dreissena polymorpha and Dreissena bugensis) and on macroinvertebrate community between 2003 and 2006 in the littoral zone of Green Bay, Lake Michigan. J Great Lakes Res 34:690–697CrossRefGoogle Scholar
- Poos M, Dextrase AJ, Schwalb AN, Ackerman JD (2010) Secondary invasion of the round goby into high diversity Great Lakes tributaries and species at risk hotspots: potential new concerns for endangered freshwater species. Biol Invasions 12:1269–1284. doi: 10.1007/s10530-009-9545-x CrossRefGoogle Scholar
- Valová Z, Jurajda P, Janáč M (2006) Spatial distribution of 0 + juvenile fish in differently modified lowland rivers. Folia Zool 55:293–308Google Scholar
- Vašek M, Všetičková L, Roche K, Jurajda P (2014) Diet of two invading gobiid species (Proterorhinus semilunaris and Neogobius melanostomus) during the breeding and hatching season: no field evidence of extensive predation on fish eggs and fry. Limnologica 46:31–36. doi: 10.1016/j.limno.2013.11.003 CrossRefGoogle Scholar