A Waterloo research project has found that the bloody red shrimp - the newest invasive species to the Great Lakes - competes very little with native species for food.
Biology Professor Michael Power and former graduate student Jessica Ives tracked the food sources of the bloody red shrimp (Hemimysis anomala) to determine its uniqueness in the food web. The more unique the species, the greater the impact it can have on other native species.
They used stable isotopes to study whether the shrimp were eating from the bottom of the lake or higher up in the water column. This provided a whole food web and ecosystem analysis as opposed to catching and dissecting individual animals to determine their eating habits.
The results showed that the bloody red shrimp is an opportunistic feeder that lives on what’s available. At every site studied, the shrimp fill the easiest niche, competing very little with other species already present.
Although researchers are finding the bloody red shrimp is having less of an impact than originally feared, scientiests are continuing to track Hemimysis and are encouraging boaters traveling between water bodies to take measures to prevent Hemimysis’ further spread.
Europe’s tiny hitchhiker
The bloody red shrimp travelled from the Caspian and Black seas via commercial shipping ballast water. It has disrupted the food web in rivers in Western Europe and altered nutrient and contaminant cycles of the environments it has invaded. The shrimp has been known to reduce zooplankton biomass and biodiversity — an important food source for young fish and a critical part of the ecosystem.
The bloody red shrimp hides from its predators during the day and comes out at night to feed, which helps it avoid becoming a food source itself.
The bloody red shrimp can travel in large, dense swarms toward the surface. This vertical migration results in the continuous cycling of pollutants such as heavy metals that would otherwise be confined to the bottom of the lake.
Ives graduated with her Master of Science from Waterloo's Biology department in 2013 and continues to be involved with invasive species as a Fishery Research Program Associate at the Great Lakes Fishery Commission.
“The Great Lakes fishing industry is a $7 billion per year business. Anything affecting this sector affects everyone living in the region.”JESSICA IVES, Great Lakes Fishery Commission
Photo credit: S. Pothoven