Canned tuna is not so good for fish oil, but is still a healthy fish. For your heart's sake buy canned salmon in brine, not oil.
Types of oily fish
Some of the most popular types of oily fish are: salmon, trout, sardines, swordfish, whitebait, fresh tuna, anchovies, eel, kipper, mackerel, carp, bloater, smelt, bluefish and sprats.
Take note that although fresh tuna is an oily fish, tinned tuna is not regarded so, as most of the oil is removed in the canning process. However, other types of oily fish that can be tinned such as sardines and anchovies, still count as oily fish.
In the same way, smoked oily fish also still counts as oily fish.