They are the most delicious fresh water fish - delicate light white flesh, sweet, not fishy tasting at all. Since they are about the size of a finger or a little larger, it takes a long time to clean enough for a good meal, but they are so worth it. And available only for a short time in early spring. I do prefer lemon juice on mine.
When I was young we went smelt dipping in the UP. Folks sat alongside rivers and creeks near the Great Lakes, waiting for the fish to run upstream to spawn. Catching them using hand nets to scoop them up. Now the smelt hardly run at all - they are much more rare in Lakes Michigan and Huron. The fisheries here bring them in from Lake Superior.