search google for 'pondboss' and PK shrimp. They are the northern strain that overwinter even in bitter cold ice covered northern ponds. They are not the strain sold in pet stores. Although in southern states, those shrimp (glass or ghost are common names, many species are available warm water only) should do great.
Shrimp cannot burrow, certainly not 2-3 feet. Crayfish do.
Shrimp have very few if any downsides. Sourcing the northern cold tolerant shrimp has become the biggest hurdle so far. It is a great opportunity waiting for the correct entrepenuer
