Eichhornia crassipes has the potential for high environmental impact if introduced to the Great Lakes. Eichhornia crassipes grows in thick mats that reduce the light and oxygen availability in the water (Ivanov 2006). After removing E. crassipes from Lake Victoria by cutting, there was a significant increase in dissolved oxygen (Osumo 2001). In Africa, Eichhornia crassipes can be detrimental to water availability due to its high rate of evapotranspiration and its ability to take advantage of scarce water reserves, resulting in an annual loss of 7 billion m3 of water from the Nile River (De Groot 1993, Padilla and Williams 2004). In China, E. crassipes has exacerbated water pollution by absorbing heavy metals and releasing them at death (Jianqing et al. 2001).
In Lake Okeechobee, E. crassipes displaced native bulrush and shaded out native submerged plants that provide important habitats for fish, waterfowl, and other animals (University of Florida 2013). In Caohai and Dianchi lakes in Yunnan province, southwestern China, E. crassipes competed with native plants for water, nutrients, and space, and contributed to the reduction in native plant diversity (Jianqing et al. 2001).
Eichhornia crassipes can potentially alter predator-prey relationships. In San Joaquin Delta, California, insect densities where lower in patches of E. crassipes and there was a difference in insect composition between E. crassipes and the native pennywort (Hydrocotyle umbellata)(Toft 2000). Non-native introduced amphipods such as Crangonyx floridanus were more abundant in E. crassipes than in the native pennywort, and are not frequently consumed by fish. Fish preyed heavily on native amphipod Hyalella azteca that was more abundant in the native pennywort. It is suggested that the presence of E. crassipes may influence native invertebrate community assemblages.
Eichhornia crassipes has the potential for high socio-economic impact if introduced to the Great Lakes.
Eichhornia crassipes can pose a risk to human health by providing a habitat for mosquitos, and may increase the risk of mosquito-borne diseases (Jianqing et al. 2001, Mailu 2001). This species has reduced water availability in Lake Victoria Basin, which led to social conflicts over the lack of clean water (Mailu 2001). In addition, the infestation of E. crassipes resulted in increased transportation costs, blockage of irrigation canals, and difficulties in electricity and water extraction. Due to E. crassipes infestation, the Kenyan port of Kisumu reported a 70% decline in economic activities. This species can impact recreational fishing by making it difficult to access fishing grounds and preventing boating (Mailu 2001, Richardson and Wilgen 2004).
In Benin, the infestation of E. crassipes was estimated to significantly reduce the annual income of the villagers, who relied on fishing and trade for an income (De Groote et al. 2003). Biological control of the infested waters in Benin was estimated to be US $2.09 million.
Eichhornia crassipes has the potential for moderate beneficial impact if introduced to the Great Lakes.
Eichhornia crassipes is an ornamental plant used in water gardens. Eichhornia crassipes has the potential to be used for bioethanol and biogas production, electricity generation, industrial uses, animal feed, or agriculture (Jafari 2010, Malik 2007). It may be utilized for wastewater treatment or heavy metal remediation (Pinto et al. 1987).