well for a kid.... just go down to the bulkheads at the canal. Go to Joes and see if the back door is open walk in and ask them if they have any broken clams....( i used to work there and thers always broken clams). If the door is closed go in the front way and ask to buy them tell them there for bait. Take a freshwater rod and go catch all the chogies(sea perch you want) If you go over to the beging of the marina there might be some flounder sitting there on the bottom.
but i think your son will have a ball catching those choggies...theyl keep eating as long as you have bait..