Like many aquatic invasive species in the Great Lakes region, the spiny water flea is native to the Ponto-Caspian region of Eastern Europe and Asia. Non-native species from this region, including the spiny water flea, are taken up in the ballast water of transatlantic shipping vessels and released into the Laurentian Great Lakes through the St. Lawrence Seaway, which connects the Great Lakes to the Atlantic Ocean. The spiny water flea was discovered in Lake Huron in 1984 and rapidly spread to each of the other Great Lakes over the next ten years. Since, the spiny water flea has established in hundreds of inland lakes in the Great Lakes region of Canada and the U.S. by hitchhiking on recreational boats.
The first SWF population in Wisconsin was discovered in 2003 in the Gile Flowage (Iron County). The UW Center for Limnology (CFL) discovered the second population in Northern Wisconsin in Stormy Lake (Vilas County) in 2007. In 2009, the UW CFL detected the spiny water flea in each of the Yahara Chain of Lakes (Mendota, Monona, Waubesa and Kegonsa) in Madison. These inland lakes act as a source of spiny water flea propagules to nearby, susceptible lakes; facilitating it’s spread across Wisconsin.
Though the spiny water flea is small (10-20 mm as an adult) compared to other aquatic invasive species, its impact as an abundant predatory zooplankter can be quite large. It has been estimated that the Lake Huron spiny water flea population consumes more zooplankton than all the fish and other invertebrate predators in the lake combined (Bunnell et al. 2011). Because of this, zooplankton biomass and biodiversity is often dramatically reduced in invaded lakes (Yan et al. 2002,
Barbiero and Tuchman 2004, Strecker et al. 2006). This reduces the zooplankton prey available to native fishes and reduces the grazing pressure on algae by zooplankton, which negatively impacts water clarity (Strecker and Arnott 2008).
In Lake Mendota, managers rely on the large algae-grazing zooplankter Daphnia pulicaria to maintain clear waters despite high algal production due to large amounts agricultural run-off into the lake. Since the spiny water flea invasion, Lake Mendota has seen a 95% reduction in D. pulicaria abundance and, in turn, a one-meter decrease in Secchi depth (Figure 1). Researchers at the UW CFL are investigating the adverse effects spiny water flea will have on water clarity management in a highly agricultural landscape.
There are no management tools to reduce or eradicate an established spiny water flea population, which underlines the importance of controlling the further spread of the invader. Therefore, the UW CFL has worked to understand which Wisconsin lakes are most susceptible to a spiny water flea invasion. The current understanding of the spiny water flea’s habitat range is that it is most likely to establish a population in deep, clear and cold lakes (Grigorovich et al. 1998, MacIsaac et al. 2000,Branstrator et al. 2006). However, the discovery of large populations of the spiny water flea in lakes like Lake Mendota or reservoirs like the Gile Flowage suggest that the spiny water flea may be able to tolerate and thrive in a much wider range of physical and chemical lake characteristics.
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Branstrator, D. K., M. E. Brown, L. J. Shannon, M. Thabes, and K. Heimgartner. 2006. Range expansion of Bythotrephes longimanus in North America: Evaluating habitat characteristics in the spread of an exotic zooplankter. Biological Invasions 8:1367–1379.
Bunnell, D. B., B. M. Davis, D. M. Warner, M. A. Chriscinske, and E. F. Roseman. 2011. Planktivory in the changing Lake Huron zooplankton community: Bythotrephes consumption exceeds that of Mysis and fish. Freshwater Biology 56:1281–1296.
Grigorovich, I., O. Pashkova, Y. Gromova, and C. van Overdijk. 1998. Bythotrephes longimanus in the Commonwealth of Independent States: variability, distribution and ecology. Hydrobiologia 379:183–198.
MacIsaac, H., H. Ketelaars, I. Grigorovich, C. Ramcharan, and N. Yan. 2000. Modeling Bythotrephes longimanus invasions in the Great Lakes basin based on its European distribution. Archiv Fur Hydrobiologie 149:1–21.
Strecker, A. L., and S. E. Arnott. 2008. Invasive predator, Bythotrephes, has varied effects on ecosystem function in freshwater lakes. Ecosystems 11:490–503.
Strecker, A. L., S. E. Arnott, N. D. Yan, and R. Girard. 2006. Variation in the response of crustacean zooplankton species richness and composition to the invasive predator Bythotrephes longimanus. Canadian Journal of Fisheries and Aquatic Sciences 63:2126–2136.
Yan, N., R. Girard, and S. Boudreau. 2002. An introduced invertebrate predator (Bythotrephes) reduces zooplankton species richness. Ecology Letters 5:481–485.