Gobius burmeisteri Kessler, 1877, G. gymnotrachelus Kessler, 1857, G. macropus De Filippi, 1863, Mesogobius gymnotrachelus (Kessler, 1857), M. g. otschakovinus Zubovich, 1925

Nonindigenous Occurrences: Babka gymnotrachelus has extended its geographical distribution to include the Baltic Sea basin (Danilkiewicz 1998). Babka gymnotrachelus has been observed in the Yantra River of the Danube, Bulgaria (Vassilev et al. 2008). Babka gymnotrachelus was first collected in the Almer Grube from the Upper Danube River, Germany in May 2011 (Haertl et al. 2012). It was first observed in 1995 in the middle section of Bug River, which is a tributary of the Vistula River in Poland (Grabowska and Grabowski 2005). It was first reported in Slovakia in 1999 and is now invasive after locally expanding its range from the Danube delta (Košco et al. 2010). It has been observed in the River Vistula (Marszal et al. 2004). Babka gymnotrachelus has recently established populations in the Evros river in Greece (Zogaris et al. 2019).

Potential pathway(s) of introduction: Transoceanic shipping (ballast water)

Babka gymnotrachelus currently does not occur near waters connected to the Great Lakes basin. It produces sticky eggs (Kottelat and Freyhof 2007); however, it is unknown whether the eggs can foul vessels and survive transoceanic transport. This species is not stocked, commercially cultured, or sold in the Great Lakes region.

This species is present in ports that are in direct trade with the Great Lakes (NBIC). Adults can survive transport in ships (Kottelat and Freyhof 2007). Other species of gobies have been introduced outside their native range via shipping and ballast water: Round Goby (Neogobius melanostomus), freshwater Tubenose Goby (Proterorhinus marmoratus), Monkey Goby (Neogobius fluviatilis), and Bighead Goby (Neogobius kessleri) (MacIsaac et al. 2001; Stepien and Tumeo 2006; Neilson and Stepien 2009). Ballast water exchange using full strength seawater for 48 hours will result in 100% mortality of Babka gymnotrachelus (Ellis and MacIsaac 2009). Ballast water exchange requires filling ballast tanks with full strength seawater for 5 days; ballast water exchange regulations may prevent introduction of Babka gymnotrachelus. Babka gymnotrachelus may be introduced to the Great Lakes via ships declaring “No Ballast on Board” (NOBOB), which are exempt from ballast water exchange. The majority of ships entering the Great Lakes are NOBOB vessels and 43% of these ships contain residual water with less than 10‰ salinity (Johengen et al. 2005). In the study, the temperature of the residual water from the vessels sampled ranged from -0.7 to 23.9°C; thus Babka gymnotrachelus is likely to survive the salinity and temperature of the NOBOB ballast water.

Babka gymnotrachelus is native to the Ponto-Caspian basin and is also found in the Danube, Dniester, and the Bug rivers (Pinchuk et al. 2003). The Main-Danube Canal is one of the main dispersal routes for invasive Ponto-Caspian species to move into Central Europe (Leuven et al. 2009). It is currently expanding its range into Eastern, Central, and Western European waters (Borcherding et al. 2011; Haertl et al. 2012; Kalchhauser et al. 2013), and has reached the Baltic Sea (Danilkiewicz 1998). Its increased distribution in Europe has been attributed to canal construction and shipping (Kalchhauser et al. 2013).

Babka gymnotrachelus has a high probability of establishment if introduced to the Great Lakes (Confidence level: Moderate).

The native and introduced ranges of Babka gymnontrachelus have similar climatic and abiotic conditions as the Great Lakes (Reid and Orlova 2002; Grigorovich et al. 2003; U.S. EPA 2008). This species occurs in waters where there is ice cover in the winter and can tolerate low oxygen levels (Charlebois et al. 1997; Reid and Orlova 2002); it is likely capable of overwintering in the Great Lakes. Babka gymnotrachelus feeds on soft-bodied invertebrates, which are common in the waters of the Great Lakes. Its establishment may be aided by the presence of Ponto-Caspian amphipods that are part of its diet (see ‘Invasional Meltdown Hypothesis’) (Simberloff & Von Holle 1999; Grabowska and Grabowski 2005; Gallardo and Aldrige 2015). However, in a laboratory study, Babka gymnontrachelus was found to preferentially consume a native central European gammarid over two Ponto-Capsian gammarids (Blonska et al. 2015). Although the presence of some species in the Great Lakes, such as Ponto-Caspian amphipods, may facilitate the establishment of Babka gymnotrachelus, the presence of other species may do the opposite. The Round Goby, a Ponto-Caspian fish that has established in the Great Lakes, is more aggressive than Babka gymnotrachelus and may deter its establishment (Charlebois et al. 1997).

In a feeding experiment, Babka gymnotrachelus exhibited aggressive behavior towards Cottus gobio, a European bullhead experiencing declining populations (Kakareko et al. 2013). Babka gymnotrachelus obtained food more quickly than Cottus gobio, and displaced it from the feeding area. Babka gymnotrachelus may have a competitive advantage over non-aggressive fish when foraging. If introduced to the Great Lakes, Babka gymnotrachelus may compete with fish that forage for invertebrates during the night. There is a great level of dietary overlap between Babka gymnotrachelus and native percid fish in the Danube River (Copp et al. 2008). However, in some cases, Babka gymnotrachelus avoids resource competition with native fish due to dissimilar foraging habits; in the Baltic Sea, this species exhibits spatial segregation while foraging to avoid competition with native fish (Grabowska and Grabowski 2005, Kakareko et al. 2003). The opportunistic feeding strategy of Babka gymnotrachelus may aid its establishment.

It exhibits an extended spawning period and parental investment, which may facilitate the establishment of a self-sustaining population (Grabowska 2005). The models of Kolar and Lodge (2002) predict that Babka gymnotrachelus will quickly establish in the Great Lakes if introduced based on growth rate, tolerance ranges for temperature and salinity, history of invasiveness, and diet. Altered streamflow patterns and warming waters attributed to climate change may render the Great Lakes more similar to the Ponto-Caspian environment.

Babka gymnotrachelus may expand its range after introduction. Intraspecific competition promotes active dispersal and may aid in the establishment of new territory (Grabowska et al. 2019). It has moved from its native range and spread into the Danube River via the Main-Danube Canal (Haertl et al. 2012). This species has exhibited spontaneous range expansion from the Danube delta to waters in Slovakia (Košco et al. 2010). This species expanded its range 70-100 km upstream in one year, from the Danube to the Polsko Kosovo of the Yantra River (Vassilev et al. 2008). In the Yantra River, Babka gymnotrachelus was the 2nd most abundant and 2nd most frequently found Ponto-Caspian gobiid. Babka gymnotrachelus invades habitats with disturbed temperature and flow regimes, such as waters altered by hydropower dams and power plant outlets (Harka and Bíró 2007; Kalchhauser et al. 2013).

Summary of species impacts derived from literature review. Click on an icon to find out more...

Environmental	Socioeconomic	Beneficial

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.

*Ballast water regulations applicable to this species are currently in place to prevent the introduction of nonindigenous species to the Great Lakes via shipping. See Title 33: Code of Federal Regulations, Part 151, Subparts C and D (33 CFR 151 C) for the most recent federal ballast water regulations applying to the Great Lakes and Hudson River.

Note: Check federal, state/provincial, and local regulations for the most up-to-date information.

Control
Biological
There are no known biological control methods for this species.

Physical
It has been suggested range expansion of Babka gymnotrachelus can be limited by avoiding ballast water collection at night when these fish are actively feeding (Hayden and Miner 2009, Hensler and Jude 2007, Kornis et al. 2012).

Chemical
There are no known chemical control methods specific to this species. General piscicides (such as rotenone) may be used for control, but expect significant kill of non-target species.

Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.