Chaetogammarus warpachowskyi G.O. Sars, Gammarus warpachowskyi (Sars 1897)

Nonindigenous Occurrences: Echinogammarus warpachowskyi was intentionally introduced into the Gulf of Finland by hydrobiologists in the 1960s (Olenin and Leppäkoski 1999). Echinogammarus warpachowskyi was intentionally introduced to the Lithuanian lakes in attempts to increase productivity of fisheries (Arbaciauskas and Gumuliauskaité 2007). This species also occurs in the Baltic Sea and its tributaries (Casties et al. 2016). Considered nonindigenous in the Dnieper River catchment (Borza et al. 2017) and in some Volga River reservoirs, including the Saratov and Kuybyshev Reservoirs (Kurina 2017a,b).

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

Echinogammarus warpachowskyi has expanded its range from the Ponto-Caspian basin via human mediated vectors and is currently present in Northwest Russia, Gulf of Finland, as well as the Baltic Sea and its tributaries (Berezina 2007). This species occurs in ports that have direct trade connections with the Great Lakes (NBIC 2009). It has been proposed that based on its natural occurrence in brackish waters, E. warpachowskyi may be able survive partial to complete ballast water exchange. As a result, this species has been assessed by some researchers as having a high Great Lakes invasion risk from both ballast-on-board and no ballast-on-board vessels (Grigorovich et al. 2003). Although Echinogammarus warpachowskyi possesses the ability to survive a wide range of salinities, it experiences partial mortality with exposure to full-strength seawater for 1 hour, and 100% mortality after 48 hours (Santagata et al. 2008).

Echinogammarus warpachowskyi has a moderate probability of establishment if introduced to the Great Lakes (Confidence level: Moderate).

The native and introduced ranges of Echinogammarus warpachowskyi have similar climate and abiotic conditions to that of the Great Lakes (Reid and Orlova 2002; Grigorovich et al. 2003; U.S. EPA 2008). The Great Lakes has similar chlorophyll α concentrations as the Ponto-Caspian basin, which may facilitate Echinogammarus warpachowskyi establishment. With the progression of climate change, it is predicted that warmer waters and increased salinization of the Great Lakes will make it more similar to the conditions of the Ponto-Caspian (U.S. EPA 2008). Of the Ponto-Capsian crustaceans established in Lithnaunian waters, E. warpachowski is one of three species that best adapted to freshwater and are widely distributed in rivers and lakes (Arbaciauskas et al. 2011). This species can tolerate mesotrophic and well-drained eutrophic lakes with high oxygen demands (Arbaciauskas 2005); it is likely to find a suitable habitat in the Great Lakes basin. This species is highly mobile, and may migrate to favorable conditions (Olenin and Leppäkoski 1999). Echinogammarus warpachowskyi may be capable of surviving low oxygen levels under the ice during the winters of the Great Lakes; it can tolerate dissolved oxygen levels as low as 0.308 mg/L (Arbaciauskas and Gumuliauskaité 2007). This species is omnivorous with shifting food strategies (Berezina 2007); Echinogammarus warpachowskyi is likely to find a food source in the Great Lakes. Echinogammarus warpachowskyi may be preyed on by fish in the Great Lakes, which may reduce its probability for establishment to some degree. The temperatures in the Great Lakes basin are slightly lower than the Ponto-Caspian region (U.S. EPA 2008); broods of Echinogammarus warpachowskyi may be relatively smaller in the Great Lakes. However, warmer temperatures due to climate change may result in larger broods, aiding the establishment of this species. Historically, Echinogammarus warpachowskyi has spread locally from where it has been introduced (Arbaciauskas 2005). It is mobile (Olenin and Leppäkoski 1999).

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

Environmental	Socioeconomic

Mastitsky et al. (2014) could not find any information pertaining to Echinogammarus warpachowskyi as a host to high impact parasites outside of the Great Lakes region. Establishment of Echinogammarus warpachowskyi in other areas resulted in a 2-fold decrease in community diversity (Arbaciauskas et al. 2010). Due to the high fitness of Echinogammarus warpachowskyi, there is an increase in its biomass where it has been established. It reached densities up to 600 ind/m2 in the Saratov Reservoir, but due to its small size had a relatively low biomass density (Kurina 2017).

There is little or no evidence to support that Echinogammarus warpachowskyi has the potential for significant socio-economic impacts if introduced to the Great Lakes.

It has not been reported that Echinogammarus warpachowskyi poses a threat to human health or 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.

There is little or no evidence to support that Echinogammarus warpachowskyi has the potential for significant beneficial impacts if introduced to the Great Lakes.

It has not been indicated that Echinogammarus warpachowskyi can be used for the control of other organisms or improving water quality. There is no evidence to suggest that this species is commercially, recreationally, or medically valuable. 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
It is possible to reduce the ballast transfer of freshwater and estuarine organisms through high-salinity exposure, which causes osmotic shock, increasing the mortality rate of organisms (Santagata et al. 2008). Under exposure to full strength sea water, Echinogammarus warpachowskyi experiences 100% mortality after 24 hours.

Physical
There are no known physical control methods for this species.

Chemical
There are no known chemical control methods for this species.