Water spotter

Thermocyclops crassus

The U.S. Environmental Protection Agency (EPA) confirmed the presence of a new non-native species in the Great Lakes in November, first spotted by a team of researchers from the U.S. agency and Cornell University.

The microscopic zooplankton species, Thermocyclops crassus, was identified after careful analysis of samples collected between 2014 and 2016 in Western Lake Erie. It becomes the first invasive species found in the Great Lakes since 2006, when the bloody-red shrimp Hemimysis anomala was discovered. Native to Eastern Europe, Asia, Africa and Australia, Thermocyclops crassus is commonly found in warm, nutrient-rich waters.

The EPA has not been able to determine how disruptive the species will be to the Great Lakes ecosystem, although it did note that it hasn’t had much impact in nearby Lake Champlain since its arrival there in 1991. Roughly 185 invasive species now exist in the Great Lakes, with most causing limited damage to the native ecosystem. Others, like the Zebra mussel, have been extremely destructive.

Scientists are unclear how Thermocyclops crassus entered the Great Lakes system, but the most likely cause is ship ballasts. Conservationists have credited the U.S. government decision in 2008 to harmonize its standards with Canada by requiring all foreign ships entering the St. Lawrence Seaway to flush their ballasts with ocean saltwater for curbing the further spread of invasive species, but ballast disinfection systems are still not a requirement.

Officials from Environment Canada and the EPA are planning to conduct more sampling to determine how established Thermocyclops crassus is in Lake Erie.

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