Fish and shellfish are valuable assets as food, so much so that the government has a Bureau of Fisheries, and has established stations at intervals on the coast and on inland lakes for the study and production of those foods that come from salt and fresh water. We have used these products of the waters as if the supply were limitless, forgetting that fish and shellfish are living creatures with habits that we cannot ignore without working havoc to the species. Young salmon and shad are hatched in the upper reaches of the rivers, and if we insist on trapping the mature fish at the river mouth on their northern migrations, the number of young decreases, and salmon and shad become high-priced foods. To ignore fishery and game laws is an ignorant and dishonest proceeding, with far-reaching economic results.
In Bulletin No. 28 of the Office of Experiment Stations, United States Department of Agriculture, forty-four different fish are listed, all used as food. A visit to the fish stall in the market of a seaboard city will acquaint you with many interesting species. Fresh and salt water fish differ in flavor, and there is a difference to be detected between fish from running, or from lake water, brook trout, for instance, having a superior flavor. The food supply also influences the flavor, and both fresh and salt water fish have a better flavor when taken from sandy and rocky bottoms rather than muddy. The habit of the fish also has an effect on the quality and taste. The chequit, for instance, is so sluggish and easy to catch that it is sometimes called "lazy" or "weakfish," and it is watery and poor flavored compared with the shad, a fish of more vigorous habits. The amount of fat also causes a difference in flavor, such high flavored fish as salmon and shad containing much fat. The distinctive flavors of mackerel and herring are apparently not due to fat, since their fat content is not particularly high. Among the most common and best liked fish are bass, black-fish, bluefish, cod, flounder, haddock, halibut, herring, mackerel, porgy (sometimes called scup or scuppaug), salmon, shad, smelt, weakfish, whitefish. Brook trout and salmon trout are luxuries.
Fig. 65. - Composition of fish.
Figure 65 shows the composition of several kinds. Compare their composition with that of meat. The nutritive content is high, yet fish seems a lighter and less satisfying food than meat, although on the seaboard of some countries it is the chief animal food. The digestibility of fish and meat are about equal, but some varieties of fish are less digestible than others, this being true of the oily and strong-flavored fish, - herring, mackerel, salmon, and shad.
There are popular prejudices for and against fish that are not warranted. The idea that fish is a "brain food" because it contains phosphorus was exploded long since, for fish contains no more phosphorus than some other foods, and phosphorus is no more valuable to the brain than to the other tissues.
Fish, however, is valuable in the dietary for supplying protein and giving variety, and in season, it is one of the cheaper foods.