See smelting for the chemical process.
Smelt is the name of several species of small anadromous fish of the family osmeridae. They are common in the Great Lakes, and run in large schools along the coastline during their spring migration to their spawning streams. The fish usually reach only 6 inches (15 cm) and are a food source for salmon and lake trout. It is one of the few fish that sportsmen are allowed to net, using gill nets, either along the coastline or in the streams. Some sportsmen also icefish for smelt. Smelt are often fried and eaten whole.
Smelt roe is bright orange in color, and is often used to garnish sushi.
The Boy's Own Book of Outdoor Sports (early 1900s) adds:
In the United States this fish seldom exceeds ten inches in length, and the usual size is from five to eight inches. In South America they grow to the length of two feet, are semi-transparent, and are most delicious eating. Some of them caught by American sailors at the Straits of Magellan were thirty inches long by eight inches round the body. The smelt is exceedingly plentiful in the waters around Boston, and they are also taken in the rivers of New jersey and the ponds of Long Island. They are of a pale green color on the back, with silvery sides, and a satin band running along the sides. They may be called a sea fish, though they run up fresh water streams in the spring to spawn. They are caught in October and November, and in the winter months by breaking holes in the ice. The tackle used for the smelt is a silk, or silk and hair line, with Limerick trout hooks Nos. 2 to 5, on single gut leaders. The sinker should be pretty heavy to overcome the tide. Shrimp bait is generally used, or small pieces of minnow or frog will answer. If you wish to fish them through a hole in the ice, take a piece of small brass wire a foot and a half long, put it through a piece of lead for a sinker, and fasten your hooks at both ends. Tie on a cotton or flax line and then drop your hooks. You can use three or four of these lines at different holes, setting them, while you are either skating or running round to keep warm. In this way you will get a fine string of smelts in a short time. Smelts will live, breed and thrive when transferred to fresh water ponds; and by some people these fresh water smelt are considered the best eating. They live a long time out of water and hence are good eating after being carried long distances.