How will one of the most recent species to invade the Great Lakes affect Lake Erie?
Alicia Pérez-Fuentetaja, research scientist with the Great Lakes Center and associate professor of biology, is conducting research into Hemimysis anomala, commonly referred to as “bloody red shrimp.”
Despite its name, the tiny creature (less than half an inch) is neither a shrimp nor bloody, although it does have certain red-colored spots that give it its common name. It has already been found in New York in Lake Ontario, Lake Erie, Seneca Lake, and Oneida Lake.
Scientists know very little about how this species interacts with its environment, so they cannot predict what effect it will have on Lake Erie as it establishes itself there. Pérez-Fuentetaja, a food-web biologist, said, “To understand how any invasive species will affect an ecosystem, you need to start by learning what it feeds on. The easiest way to do that is with lab experiments.”
That’s why the lab incubator has several tanks of bloody red shrimp and several jars of Daphnia, a tiny crustacean that the shrimp preys upon. “We know that Hemimysis is omnivorous,” said Pérez-Fuentetaja, “but we don’t know the proportion of plant and animal matter in their diet.”
With graduate student Jessica Wuerstle, Pérez-Fuentetaja is investigating both the size and composition (plant or animal) of the food that bloody red shrimp prefer by offering a carefully selected choice of food to the shrimp. “After we run an experiment,” said Pérez-Fuentetaja, “we examine the amount and size of prey Hemimysis has consumed or attacked, and the gut contents to see what it has eaten.”
This painstaking research lays the groundwork for assessing what risk, if any, the new species presents to Lake Erie. Another question that has yet to be answered is whether anything eats the bloody red shrimp. “So far,” said Pérez-Fuentetaja, “we haven't found them in fish stomachs in eastern Lake Erie, although in Lake Ontario they are showing up in some fish guts. We just don't know enough yet about their ecological role in Lake Erie.”
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