CS17 Invasive Species
Date: Thursday, June 13, 2002
Time: 2:30:00 PM
Location: Sidney
 
FosterSE, University of Toronto at Mississauga, Mississauga, Canada, sfoster@utm.utoronto.ca
Sprules, W, G, University of Toronto at Mississauga, Mississauga, Canada, gsprules@cyclops.erin.utoronto.ca
 
TOWARDS A SYNTHESIS OF INVASIVE INVERTEBRATES IMPACTS ON NATIVE FOOD WEBS
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The rate of species introductions into freshwater communities is increasing worldwide. Many invertebrates have been introduced both intentionally and accidentally however their impacts are not well documented. In this study we review current knowledge on the effects of invertebrate invaders on aquatic food webs. Species replacement has been documented as a result of several invertebrate invaders and increasingly effects on fish production are being recognised. Because aquatic invertebrates inhabit diverse habitats and tend to have intermediate trophic positions, their possible impacts are complex. For example, zooplankton predators such as Bythotrephes and Cercopagis, recent invaders in the Great Lakes and historical invaders in other systems, elongate food chains and may affect availability of food resources for planktivorous and juvenile fish. Filter feeders, such as, Dreissena spp. can also have significant effects on fish communities by reducing primary production and increasing nearshore habitat complexity. The ecological and economic costs of invasive invertebrates are potentially high and more attention needs to be devoted to preventing their arrival, predicting their effects once they have arrived and minimizing their impact.