Do I need a fresh water fishing license to fish in the marshes?

I recently got a marine fishing license. However, I'm a fresh water fishing guy so have barely any salt water tackle with the exception of a couple of poles and reels. No terminal tackle.

What I would like to try one of these days is crabbing and based on one advice so far, I should try crabbing in the marshes. Could I cast in the marshes without a fresh water license if I hold a marine license? It would give me something to do while wait for the 5-10 minutes before I can pull up the crab basket.

I found the guide. Very helpful. Where is route 122? Indian River and Oyster River is demarced by Route 122, which I don't see on the map. Is it Route 162? Thanks.