Invasive shrimp spells trouble for Great Lakes food webs
Ann Arbor, MI — An invasive freshwater shrimp native to the Black Sea region is predicted to cause major changes to Great Lakes food webs.
Called "the bloody red mysid", this small predatory crustacean was discovered a few years ago and has now been found in all the Great Lakes except Lake Superior.
Whenever a new invader is discovered, wildlife managers consult published studies to assess its potential environmental impact so that they can prioritize invasion threats. Often there is very little information available for risk assessment, because the effects of the invader might not have been well documented elsewhere.
However, researchers can look to the invasion history of closely-related species for answers. A team of Canadian scientists have examined global data showing that when mysid shrimp are introduced to a lake, they almost always cause declines in zooplankton abundance, which can indirectly affect fish populations. The activities of these shrimp may also contribute to algal blooms and increased accumulation of contaminants in fish near the top of the food web.
"The documented history of similar invaders provides valuable clues that can help us anticipate the impacts of this species", explains Dr. Anthony Ricciardi, a biologist at McGill University. "Mysid shrimp are repeat-offenders, which suggests that at least some of their impacts are predictable." But how big an impact they have depends on their population size. It remains to be seen to what extent invasive shrimp populations in the Great Lakes will be limited by fish predation.
Original Publication InformationResults of this study, "Forecasting the ecological impacts of the Hemimysis anomala invasion in North America: Lessons from other freshwater mysid introductions," are reported by Anthony Ricciardi, Suncica Avlijas and Jérôme Marty in the special issue on Mysids of the Great Lakes, of the Journal of Great Lakes Research, published by Elsevier, 2011.
Contacts
For more information about the study, contact Anthony Ricciardi, Redpath Museum, McGill University, Montreal, Quebec, Canada H3A 2K6; tony.ricciardi@mcgill.ca, (514) 398-4089.
For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, Environment Canada, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; jglr@ec.gc.ca; (306) 975-5310.
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