Windsor

Killer shrimp banned in Michigan to protect Great Lakes

The killer shrimp is an aggressive predator and could severely threaten the food chain of the Great Lakes by preying on a range of invertebrates.
The killer shrimp has a large mouth and sharp claws it uses to shred their prey. (Associated Press/File Photo)

The killer shrimp is one of seven invasive species the Michigan Department of Natural Resources officially banned this month.

The ban officially came nearly a year after Mich. Gov. Rick Snyder and officials met with officials from other Great Lakes states and Canadian provinces in 2013.

The killer shrimp is an aggressive predator and could severely threaten the food chain of the Great Lakes by preying on a range of invertebrates.

The shrimp has a large mouth and sharp claws it uses to shred their prey.

Hugh MacIsaac, a scientist and professor of biology at the University of Windsor who specializes in invasive species, said the small bottom-dwelling shrimp eats just about anything it comes upon, including other species of shrimp.

The shrimp is native to the Black Sea and gained access to the European river system when a canal was dug to link the Danube and Rhine rivers. That was done to accommodate shipping traffic and those ever-popular river cruises.

MacIsaac said the shrimp can completely take over the ecosystem of a river or lakebed because they are so voracious.

According to the National Wildlife Federation, if the shrimp is introduced to the Great Lakes through ballast water, it may contribute to the threat of an "invasional meltdown" in the Great Lakes.

However MacIsaac said there is no need for panic yet.

He admits there are "no absolutes," but the chances of the killer shrimp making it into the Great Lakes is remote.

He said ships that leave Europe for North America have a process they must adhere to with regard to ballast water.

When they leave ports in Europe their ballast tanks are usually full of fresh water. When they get into the ocean they empty their tanks of the fresh water and refill them with salt water. Fresh water species, killer shrimp among them, could not survive a trans-Atlantic crossing in those tanks of salt water, MacIsaac said.

The ships from Europe are inspected at the entrance to the St. Lawrence Seaway by Canadian and American officials.
If they haven't followed the ballast water protocol, they are not permitted to pass.

Zebra mussels and gobies currently in the Great Lakes arrived here prior to the enforcement of these procedures that Canada adopted it in 2006 and the  U.S. in 2008.

The following species were also added to Michigan's prohibited species list:

  • Stone moroko, which is part of the minnow family, this species is a known carrier of a parasite that can negatively impact other fishes.
  • Zander, a close relative of the walleye, this species could compete with the native fish or reproduce with it and create a hybrid.
  • Wels catfish, which is considered a serious danger to native fish populations.
  • Yabby, a large crayfish would negatively impact other crayfish species.
  • Golden mussel, which is similar to zebra and quagga mussels, this species has destructive qualities that would threaten native biodiversity.
  • Red swamp crayfish, a species that can quickly dominate water bodies and is virtually impossible to eradicate.

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