Bloody Red Shrimp Recently Found in Lake Superior Confirms the Invasive Species’ Takeover of All Five Great Lakes

Concerns have been raised regarding the potential ecological impact of an invasive crustacean, the bloody red shrimp, which has been confirmed to have established a self-sustaining population in Lake Superior. This discovery completes the species’ spread across all five Great Lakes, a situation that could disrupt local ecosystems and alter food webs.

Researchers announced their findings in a recent edition of the Journal of Great Lakes Research, following a sampling expedition conducted in the summer of 2025. The team captured 81 specimens in Duluth-Superior Harbour, located along the borders of Wisconsin and Minnesota. The specimens included both adult and juvenile shrimp, as well as pregnant females, indicating a stable breeding population within the lake.

The bloody red shrimp, scientifically known as Hemimysis anomala, is believed to have arrived in the Great Lakes via ballast water discharged from cargo ships. Lead researcher Donn Branstrator, a biology professor at the University of Minnesota Duluth, noted that the species likely made its way to Lake Superior through regular shipping activities. “It has multiple opportunities on a weekly basis during the shipping season to hitch a ride in ballast water,” he explained.

The arrival of the shrimp in the Great Lakes was first documented in 2006 near Muskegon, Michigan, with a lone specimen spotted in Duluth-Superior Harbour in 2017. However, it wasn’t until the recent sampling that researchers confirmed its establishment. Despite its delayed arrival in Lake Superior, Branstrator suggested that geographic isolation and lower temperatures may have slowed the shrimp’s migration.

While it is still uncertain what effects the bloody red shrimp will have on the Lake Superior ecosystem, experts have raised alarms. The species is known to be broadly omnivorous, which means it may compete with native species for resources. Historical data from European sources suggest that its introduction has led to significant reductions in zooplankton diversity in various reservoirs.

The study has emphasised the ecological risks associated with the shrimp’s presence, noting that “significant ecological impacts are possible” given its invasiveness in other regions. Currently, research into the consequences of this invasion is ongoing, especially as there are no effective methods established for controlling the species within natural water bodies.

In light of these developments, local officials have yet to outline any immediate plans to mitigate the shrimp’s spread. As the species establishes itself further, the Minnesota Department of Natural Resources has acknowledged the challenge of managing this invasive crustacean in local waterways.

As researchers continue to monitor the bloody red shrimp and collect specimens biweekly at Montreal Pier, the potential risks to Lake Superior remain pronounced. Experts stress the need to understand better how this organism could affect nutrient and contaminant pathways among nearshore food webs, particularly given the absence of evidence indicating significant adverse effects thus far in the Great Lakes.

As this situation unfolds, stakeholders and environmental agencies will need to keep a vigilant watch on the ecological implications of the shrimp’s establishment. The spread of the bloody red shrimp highlights broader concerns related to invasive species and their capacity to reshape ecosystems, posing vital questions for conservation and management efforts in the future.