Caboose....You're going to love it there!! Wish I was back on that coast!
TRAPPMAN's Seafood, on the Gandy bridge. St Pete side of the causeway. Great fresh seafoods, to include live blue crabs and such. Mullet as well.
Also, a bit more of a drive, but a true St pete landmark:
MASTRY's, on 9th Street in St Pete. A true locals landmark...known for his daily arrivals of fresh mullet. The fishermen still have their boots on when they stop in with their catch. (Killer tackle shop, too!!)
Tampa Bay is full of mullet! If you don't already, its time to learn to throw a cast net!
I wish you success!!