Before the muskrats destroyed all of the APW the shrimp would hang out in there.

Now, aside from a few remnants of cattail and arrowhead that the vermin haven't yet eaten, the only vegetation in my pond is bladderwort.
Any time I mess with it I can see shrimp flipping around. The fish see them too and then poof gone no more shrimp.

Before the rats ate the APW I would catch PK every time I soaked a trap. I haven't trapped any PK since the rooted plants were wiped out.
So I'm gonna say the nice stand of APW that I used to have made a happy home for PK shrimp.