Modeling Bythotrephes longimanus invasions in the Great Lakes basin based on its European distribution

Abstract

The predatory c1adoceran Bythotrephes longimanus LEYDIG has a natural distribution that extends throughout much of the Palearctic region, and an ever increasing distribution in the Great Lakes basin of North America, where it was first observed in 1982. In this study we define characteristics of 55 waterbodies with and without Bythotrephes in Europe, and use these distributions to predict the species' occurrence in 49 lakes in the Great Lakes basin of North America. Lakes in Europe that supported Bythotrephes were significantly larger, deeper, had higher transparency and lower maximum bottom temperature during summer, and lower total chlorophyll concentration, than those that lacked the species. These patterns also were observed for lakes in North America, although differences between invaded and noninvaded ba sins were significant only for lake area and maximum depth. A discriminant fu nction model correctly predicted Bythotrephes occurrence in 91 % of study lakes in Europe, and was influenced most by Se cchi disk transparency and lake surface area. Applica tion of this model to North America correctly predicted occurrence of Bythotrephes in 82 % (1 8 of 22 ) of lakes in which the species has been recorded. However, the model incorrectly predicted Bythotrephes presence in 74 % (20 of 27 ) of lakes in which the species has not yet been observed. These fi ndings indicate that many of the study lakes in the Great Lakes basin may be vulnerable to invasion by Bythotrephes. Human activ-

Temperature, recreational fishing and diapause egg connections: dispersal of spiny water fleas (Bythotrephes longimanus)

“…Many inland lakes appear to possess habitat suitable for Bythotrephes colonization and thus remain vulnerable to invasion (MacIsaac et al 2000;Yan et al 2002). Early geographic surveys of Bythotrephes documented inland expansion (Yan et al 1992;Jarnagin 1998;Branstrator et al 2006), but until recently the exact nature of the northern geographic pattern was unclear.…”

“…After colonizing embayments through coastal water connections, Bythotrephes began to invade inland lakes (MacIsaac et al 2000(MacIsaac et al , 2004. Much of the available inland small lake information comes from Harp Lake, Ontario (Yan and Pawson 1997) and Lake Michigamme, Upper Peninsula of Michigan (Jarnagin 1998;Jarnagin et al 2000Jarnagin et al , 2004.…”

Zooplankton life cycles: Direct documentation of pelagic births and deaths relative to diapausing egg production

“…In its native Eurasian and introduced North American range, B. cederstroemi (Schoedler) appears to be a stenothermic animal with a preferred temperature range of ϳ12-18ЊC (Yurista 1997), although it can tolerate temperatures in the lower 20s. The species was first reported from the Laurentian Great Lakes region in 1982-1984 and had reached Lake Huron by December 1984, Lake Ontario by September 1985, Lake Erie by October 1985, Lake Michigan by September 1986, and Lake Superior by August 1987 (see references in MacIsaac et al 2000). The Laurentian Great Lakes now operate as a dispersal source, allowing colonization of adjacent inland lakes.…”

“…MacIsaac et al 2000), probably imported from the harbor of St. Petersburg (Gulf of Finland, Baltic Sea) via ballast water during transcontinental ship transport (Berg et al 2002). Bythotrephes is the only strictly freshwater genus of the family Cerocopagidae.…”

Dynamics of the invasive spiny water flea, Bythotrephes longimanus, in Lake Simcoe, Ontario, Canada

“…Secchi depth and TP concentrations in the late summer and early fall predicted differences in Bythotrephes seasonal abundance patterns among groups of years, lending further support to the role of water clarity as a significant component of Bythotrephes habitat in the invaded range. Bythotrephes body size and reproductive patterns also varied seasonally, which could possibly reflect the seasonal availability of cladoceran prey, predation pressure from planktivorous fish, or perhaps adaptations to avoid unfavourable conditions and persist in an environment atypical of its native range (i.e., deep, clear, oligotrophic lakes; Grigorovich et al 1998, MacIsaac et al 2000. Overall, a complex interaction of fish predation, food availability, temperature, and water clarity controls the dynamics of Bythotrephes in Lake Simcoe.…”