collecting live food from white rock safe?

[nanoreefer]

i hopeing to get afew baby cuttelfish in a week or too and sence they need small live food like mysis shrimp scuds crabs ect i was thinking of just going down to white rock and collecting afew weeks supply and keeping it in an extra tank or in the fridge but ive heard a lot about it being pretty poluted so would the shrimp/crabs be ok to feed? or is there some other source for live mysis? or something eles i could feed them?