Interactions between invasive round gobies (Neogobius melanostomus) and fantail darters (Etheostoma flabellare) in a tributary of the St. Lawrence River, New York, USA

Abstract

The initial, rapid expansion of the invasive round goby (Neogobius melanostomus) throughout the Great Lakes drainage was largely confined to lentic systems. We recently observed round gobies ascending two tributaries of the St. Lawrence River. The expansion of gobies into small lotic environments may place ecologically similar species at risk. Fantail darter (Etheostoma flabellare) is one of the several benthic species of the New York Great Lakes drainages that are threatened by round goby invasion. We examined the habitat use and diet composition of fantail darters and round gobies in Mullet Creek, a third-order tributary of the St. Lawrence River, NY, USA. The objectives of this study were to determine the degree of habitat and diet overlap between fantail darters and round gobies in a tributary of the St. Lawrence River. Gobies and darters co-occurred at 22% of capture sites. Of the four habitat variables examined (cover, depth, substrate and velocity), only depth use was significantly different with gobies using deeper habitats than darters. Among the two species and size classes sampled (large vs. small), large darters had the most restricted habitat use requirements. There was variation in round goby and darter diet composition, but only moderate diet overlap occurred between fantail darters and round gobies (Cλ ¼ 0.43). Conditions in Mullet Creek were appropriate for the evaluation of possible spatial and dietary competition between round goby and native darters. Early detection and management of round goby invasions is critical to maintaining ecological integrity of lotic ecosystems in the St. Lawrence Valley.

Summer microhabitat use and overlap by the invasive Round Goby (Neogobius melanostomus) and native darters in the Trent River (Ontario, Canada)

“…Habitat differences between Channel Darter and Round Goby were small; largely limited to Channel Darter occupying deeper habitats. In contrast to these results, Abbett et al (2013) reported Fantail Darter to occupy shallower habitats than Round Goby in a St. Lawrence River tributary (Mullet Creek). The lack of agreement between studies may reflect Trent River habitats being deeper than Mullet Creek, or that Channel Darter typically occupies deeper habitats than Fantail Darter (Stauffer et al, 1996;Reid et al, 2005).…”

“…A spot-sample electrofishing technique was used to collect darters and Round Goby and characterize habitat use (Johnson, 2008;Abbett et al, 2013). Electrofishing was limited to those wadeable habitats that could be safely and effectively sampled (water depths < 1 m).…”

“…While present in the Great Lakes for more than 25 years, the secondary invasion upstream of Round Goby into Ontario streams and rivers has been a more recent occurrence (Poos et al, 2010;Raby et al, 2010;Raab et al, 2018). Subsequent research in Great Lakes tributaries has identified that habitat and dietary competition between Round Goby and native darters is likely occurring (Abbett et al, 2013) and, in some watercourses, the distribution and abundance of small native fishes are negatively associated with Round Goby presence and abundance (Krakowiak and Pennuto, 2008;Abbett et al, 2013;Kornis et al, 2013;Raab et al, 2018).…”

“…However, these assessments were largely based on expert opinion and, therefore require validation through field research and monitoring. One of the proposed mechanisms associated with negative Round Goby impacts is competition for habitat and shelter (Balshine et al, 2005;Abbett et al, 2013). In this study, summer microhabitat use by Round Goby and two darter species (Channel Darter and Logperch) was characterized at wadeable Trent River sites, and the magnitude of habitat overlap assessed.…”

What do we really know about the impacts of one of the 100 worst invaders in Europe? A reality check

“…Other darters such as blackside darter (Percina maculate), fantail darter (Etheostoma flabellare), and rainbow darter (E. caeruleum) are suspected to have diet or habitat overlap with round goby (French and Jude 2001;Poos et al 2010;Abbett et al 2013). In tributaries of Lake Erie, no rainbow darters and johnny darters were found in any of the streams containing round goby, whereas they were present in all of the gobyabsent streams (Krakowiak and Pennuto 2008).…”