• An invasive shrimp native to the Black Sea has now infested all five Great Lakes.
• Researchers confirmed a breeding population of bloody red shrimp in Lake Superior’s Duluth-Superior Harbor.
• The small crustaceans likely arrived in the Great Lakes via ballast water from ocean-going vessels.

An invasive shrimp is swimming in Lake Superior. This is the last Great Lake to be invaded — all five Great Lakes now are infested by the crustaceans..

Researchers for the first time have confirmed a breeding population of an invasive Black Sea-native shrimp in Lake Superior.

The number and extent of the shrimp’s spread in Lake Superior is not clear. However, there is a breeding population in the Duluth.

The findings by researchers at the University of Minnesota-Duluth, Lake Superior Research Institute at the University of Wisconsin Superior, and the Hobart and William Smith Colleges in New York, published in the Journal of Great Lakes Research in April, found that the shrimp are now reproducing and surviving year-round in the Duluth-Superior Harbor, the farthest west the European species has been confirmed.

“Samples we collected in 2025 from two locations in the Duluth-Superior Harbor, a major inland shipping port in the Great Lakes, contained juveniles, adult males, and (pregnant or with young) adult females, indicating a self-sustaining population. Additionally, we document earlier evidence from 2018 samples we collected in the harbor that contained two juvenile specimens,” the article in the Journal said.

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In an interview on the CBC’s “Superior Morning” show with Mary-Jane Cormier on June 10, lead researcher Donn Branstrator, of the University of Minnesota, said studies in the Duluth-Superior Harbor this spring after ice was off the lake found adult males and females.

“It’s pretty clear evidence of overwintering,” Branstrator told Cormier. “It would be very unlikely for the population to extinguish (at this point).”

Branstrator told Cormier ongoing bi-weekly research in the harbor, and along the Lake Superior shoreline will exam those questions.

According to the research, the non-native shrimp, about a quarter to half inch long, were first detected in the lower Great Lakes in 2006 in lakes Michigan and Ontario. By 2008, they were found in lakes Huron and Erie as well.

“It has also spread to Oneida and Seneca Lakes in New York … as well as the St. Lawrence River and various canals in northern New York State,” the research said.

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Branstrator said the Black and Caspian sea region natives, also have spread throughout Europe into areas they were not native. He said they likely hitchhiked with ballast or bilge water, but the exact mechanism will never be known.

What we know about bloody red shrimp.

What is a bloody red shrimp?

Bloody red shrimp are small crustaceans native to the Black Sea and Caspian Sea region of Europe. They are adapted for fresh and brackish water.

Missouri sportsbooks took $256,364,814 in wagers in May 2026, the lowest monthly handle since the market launched, yet operators posted their strongest revenue month yet at $21,250,814 on an 8.29% hold. The state collected $2,131,872 in tax. Six months after going live on December 1, 2025, Missouri has flipped the usual relationship between volume and revenue: handle keeps settling while revenue keeps climbing, because hold has risen steadily as the launch-period promotions fade. Online betting made up $252,593,427, or 98.53% of all wagers. Figures come from the Missouri Gaming Commission.

Missouri Sports Betting by Month, Since Launch

Six Months In, Revenue Sets a Record

May marks a milestone worth pausing on. Missouri’s revenue reached its highest point yet even though its handle sank to a new low, a sign the market has moved past the giveaway-heavy launch phase and into steadier economics. Across its first six months, the state has now taken roughly $2.06 billion in total wagers, produced about $100.1 million in operator revenue, and delivered $8.2 million in tax. Crossing $100 million in cumulative revenue in half a year underlines how quickly Missouri established itself as a mid-sized market.

Handle Settles as the Launch Surge Fades

The volume side keeps normalizing. December’s $543 million opening was inflated by launch-day demand and heavy sign-up promotions, and handle has stepped down almost every month since, landing at $256.4 million in May, less than half that peak. Part of the decline is seasonal, with the sports calendar thinning as the basketball and hockey postseasons wind down and football stays months away. Part is simply the novelty wearing off. Mobile sportsbooks in Missouri continue to carry the market almost entirely, at 98.53% of May handle, a share that has held above 98% in every month since launch.

The Hold Keeps Climbing

The defining trend is the win rate. Hold ran at 3.82% in December, bottomed at 1.74% in January, then rose in four straight steps to 3.72%, 6.30%, 7.42%, and 8.29% in May. That climb is the engine behind the record revenue: as operators pull back the free bets and bonus play that suppressed early margins, more of each wagered dollar sticks. An 8.29% hold is still below the double-digit figures common in older markets, which suggests Missouri’s margin has further room to firm up as the market matures.

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