Stripers in the canal.
I usually fished the east end of the canal, but the fish run through there from both ends of course. I have fished the west end, just don't know it as well.
There are huge stripers (striped bass) in there, blues, mackerel run through there, false albacore in the fall. I've even heard rumors of football bluefin passing through. It's a great place to fish. Did I mention the huge stripers?
Cheers!
-JC
ETA: Clams, squid, cut mackerel, sea-worms, fresh pogies or herring in season fished on the bottom, or the best - eels for bait. Eels can be live or retrieved like a lure if dead. Big top-water plugs at night. Not shrimp in MA.
Gear: Something long enough and stout enough to throw some heavy metal. It can take considerable weight in the current there to hold bottom.
Go there at night sometime and see what the locals are doing. The canal really is best at night for stripers.