I finally found some sardines at the fish markets last week. I went around 7am so the market was very busy with fishermen off loading the catch of the day. The only customers were me and two Italian men wearing suits and with the most Godfather-like hair styles. They didn't quite look the part but neither did I! They looked very serious as they were selecting their fish. I imagine that they would taking it home to their Italian wives to be cooked for them for lunch.
Sardines are a great source of omega 3 and calcium. Heavy metals aren't such a problem in little fish like sardines either.