Siri said there are shrimp and oysters in the Great Lakes

[raccoon]

Did they get there naturally or did some people put them there to get them started?

[Cirsium]

1. both

There are native "oysters" (mussels) and native and non-native shrimp.

[Srkdqltr]

2. There are fresh water oysters. Used to get them in Lake St. Clair. I don't know about shrimp.

Oysters not to eat that i know of.

[surrealAmerican]

3. There are also crayfish ...

... and crabs.

[ProfessorGAC]

4. I Think The Shrimp Are REALLY Small

They're bright red. I think they're called blood red shrimp, or bloody shrimp, or something to that effect.
Pretty sure they are food for lake perch & other fish.
I remember hearing about these a long time ago, and IIRC they are under ½" long, tail to head.
So, if I remember this right, they are there, but they aren't food for people