Babka gymnotrachelus has the potential for moderate environmental impact if introduced to the Great Lakes. Babka gymnotrachelus, like the closely related Neogobius melanostomus, feeds on dreissenid mussels that act as sinks for contaminants while foraging in benthic environments (Kornis et al. 2012). These ingested contaminants may undergo biomagnification at higher trophic levels, but there is not enough evidence to conclude whether this would occur if Babka gymnotrachelus were introduced to the Great Lakes.
Babka gymnotrachelus is a host for several European parasites including the trematode Cryptocotyle concavum, the acanthocephalan Pseudoechinorhynchus (Najdenova 1974; Smirnov 1986), the monogenean Gyrodactylus proterorhini, the digenean Bucephalus polymorphus, and the ciliate Trichodina domerguei (Kvach and Mierzejewska 2011, Mierzejewska et al. 2011; Mierzejewska et al. 2014). Dreissena polymorpha is an intermediate host for Bucephalus polymorphus and is eaten by gobies. Pike and Perch that prey on gobies may be infected. Evidence suggest that populations of Racer Gobies and Round Gobies that are introduced outside their native ranges have lower parasite species richness than in their native ranges (Corkum et al. 2004; Ondracková et al. 2012), however, parasite species counts are increasing in both ranges (Kvach et al. 2020). In the Great Lakes, Dreissena polymorpha exhibits low parasite loads (Pronin et al. 1997).
If introduced, Babka gymnotrachelus may potentially compete with native Great Lakes species for food (Holcík 1991). As a non-native fish in the Danube River, Babka gymnotrachelus exhibits a strong dietary overlap with some native fishes (Copp et al. 2008). In a laboratory experiment, Babka gymnotrachelus exhibited competitive and aggressive behavior towards Cottus gobio when feeding (Kakareko et al. 2013). Babka gymnotrachelus and Cottus gobio also have wide habitat overlap, especially in areas with moderate water velocity and gravel substrate (Kakareko et al. 2016). In laboratory experiments, Babka gymnotrachelus displaced Cottus gobio from shelter even at flows above their optimal range (Jermacz et al. 2015).
In the Baltic basin, Babka gymnotrachelus avoids resource competition with native fishes through spatial segregation while foraging (Kakareko et al. 2003; Grabowska and Grabowski 2005; Plachoki et al. 2019). Babka gymnotrachelus exhibits opportunistic feeding habits and plasticity (Grabowska and Grabowski 2005). Thus, it is not clear whether Babka gymnotrachelus would outcompete native species if introduced to the Great Lakes.
Babka gymnotrachelus can potentially be preyed on by Great Lakes fishes if introduced; however, there is not enough research to determine if this species has the potential to alter predator-prey relationships. The Round Goby (Neogobius melanstomus) has altered food web structure in the Great Lakes (Corkum et al. 2004).
Dreissenids are native to the Ponto-Caspian and have increased water clarity and altered nutrient cycling regimes in the Great Lakes (Qualls et al. 2007). If Babka gymnotrachelus feeds on a substantial amount of dreissenid mussels, water clarity and nutrient cycling regimes may be impacted, but it is unknown whether this impact is positive or negative.
While not a proxy for Great Lakes native species, it is important to note that there were no significant impacts on native fish species from invasive Babka gymnotrachelus over 8 years (2008-2015) in the Danube river (Janac et al. 2018).
There is little or no evidence to support that Babka gymnotrachelus has the potential for significant socio-economic impacts if introduced to the Great Lakes.
It has not been reported that Babka gymnotrachelus poses a threat to water quality. There is no evidence that this species negatively impacts infrastructure, economic sectors, recreational activities and associated tourism, or the aesthetic appeal of the areas it inhabits.
While foraging in benthic environments, Babka gymnotrachelus ingests sediments that are a sink for contaminants. Babka gymnotrachelus, like the closely related Neogobius melanostomus, feeds on dreissenid mussels and may result in the bioaccumulation of contaminants to higher trophic levels (Kornis et al. 2012). However, the link between Babka gymnotrachelus and bioaccumulation of toxins has not been demonstrated.
Current research on the potential for beneficial impacts to result from Babka gymnotrachelus if introduced to the Great Lakes is inadequate to support proper assessment.
Babka gymnotrachelus feed on the invasive dreissenid mussels (Gaygusuz et al. 2007), but its ability as an effective biological control agent is unknown. This fish is not commercially valuable and is an insignificant part of the fishing industry in the Caspian basin (Pinchuk et al. 2003). Babka gymnotrachelus is not recreationally or medically valuable. It has not been indicated that Babka gymnotrachelus can be used to improve water quality. It does not have significant positive ecological impacts.