Are opossum shrimp in Lake Huron starving?
Ann Arbor, MI — As scientists assess the potential impacts of the invasive bloody red mysid, recent research indicates that populations of a mysid native to the Great Lakes (the opossum shrimp Mysis diluviana) might be in trouble due to a shortage of food. Mysis serves as a vital food source to many populations of fish in the Great Lakes.
In spring and summer 2008, a team of scientists from the University of Michigan and the U.S. Geological Survey’s Great Lakes Science Center sampled Mysis in lakes Michigan and Huron and analyzed their lipid content and fatty acid composition. These measurements provide indicators of the health and condition of Mysis and whether enough high-quality food is available to them in the environment.
Samples from lakes Michigan and Huron were compared to threshold levels of lipids and fatty acids that indicate starvation; these thresholds come from a 2008 study in which Mysis were deprived of food in the laboratory. "We found that Mysis in Lake Michigan were well above threshold levels for starvation during both spring and summer 2008," said Julia Mida Hinderer, the study’s lead author who conducted the work as part of her Master’s thesis. "In northern Lake Huron in spring, however, levels of lipids and fatty acids suggest that the Mysis we sampled may have been starving."
The research team was only able to sample one station from Lake Huron in spring, so results are not conclusive. A larger number of Lake Huron stations were sampled in summer, and while analysis did not suggest starvation, Lake Huron Mysis were in worse condition than Mysis from Lake Michigan.
The authors speculate that Lake Huron Mysis may have been more severely food-limited because the invasion of non-native quagga mussels was more advanced than in Lake Michigan. These invasive mussels filter out the spring bloom of diatoms, a group of algae that Mysis depend upon as a food source to recover from winter food shortages. "While we can’t conclude from our single sampling station that Mysis in Lake Huron are starving during spring, the results should raise a red flag that this organism needs to be closely monitored." said Hinderer. "This is especially important given that quagga mussels are rapidly and fundamentally altering Great Lakes food webs."
Original Publication Information
Results of this study, "Lipids and fatty acids of Mysis diluviana in lakes Michigan and Huron, 2008," are reported by Julia Mida Hinderer, David Jude, Jeffrey Schaeffer, David Warner, and Don Scavia 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 Julia Mida Hinderer, University of Michigan; midaj@umich.edu.
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.
Since 1967, IAGLR has served as the focal point for compiling and disseminating multidisciplinary knowledge on North America's Laurentian Great Lakes and other large lakes of the world and their watersheds. In part, IAGLR communicates this knowledge through publication of the Journal of Great Lakes Research, available to members in print and electronic form. A searchable archive of the journal is available online and includes the abstracts of articles from the journal's inception in 1975 through the most recent issue. In addition, complete articles are available to members who have signed up for an electronic subscription.