‘intermediate’ deep-sea nets and dredges, see Deep-Sea Exploration.
Preparation and Preservation of Fish. A matter of great importance to the fishery industry is the proper preparation of the raw product for the market. The markets are generally distant from the point of capture; moreover, the season during which any species can be taken in paying quantities is usually limited. This necessity has given rise to numerous methods of preservation, all of which are modifications of freezing, drying, smoking, salting, or canning.
Freezing. For transportation of fresh fish and for their preservation the freezing method is generally adopted. For transportation they are usually simply packed in ice. To preserve them for long periods in the fresh condition they are frozen into blocks of various sizes. The fish are packed into a pan of the desired shape and size, and then subjected to very low temperatures, either through the ice-and-salt method or by the ammonia method. Frozen into blocks, they are stored until ready for the market. Such frozen fish usually lose some of their good flavor and firmness, due to evaporation during storage. On the Atlantic Coast the bluefish, halibut, squeteague, sturgeon, mackerel, flatfish, cod, haddock, Spanish mackerel, eels, etc., are thus preserved. On the Pacific Coast the salmon, sturgeon, and halibut are principally frozen. On the Great Lakes the lake trout, lake herring, wall-eyed pike, black bass, perch, sturgeon, etc., are frozen. The comparatively recent perfection of the methods of refrigeration has greatly increased the consumption of fresh fish, and has enabled consumers to enjoy many species fresh at a season in which formerly they could be had only in a smoked or salted condition. The extensive inland trade in the United States, and the liability of stored products to rapid decay, has given rise to an elaborate system of refrigerator railroad cars for their imperishable transportation.
In Drying, fish are usually first subjected to a salt cure, but under some circumstances may be directly dried. The process varies with different species, climates, and nations, but in general is as follows: The fish are cleaned and split. They are then salted, either with dry salt, allowing the pickle which forms to run off, or in brine-vats, where they remain until ready for market. They are then subjected to the drying process in the sun, much care being essential to prevent too strong sunlight acting upon them. For markets in the tropics it is essential that most of the water be extracted, but for sale in the United States the fish are much less thoroughly dried.
For Pickling, brine is almost exclusively employed in the United States. The fish are cleaned, split, and packed in salt. Brine is then added. The principal fishes pickled are the mackerel and the herring.
Smoking Fish is an old and common practice. Smoking is a powerful preservative, and adds a desirable flavor to the flesh. The fish are usually slightly cured with salt, first, then smoked for a varying length of time—two to ten days. Oily species, such as the herring, haddock, halibut, salmon, etc., are those most generally smoked.
In Canning the flesh is subjected to high temperatures (boiled), placed in cans, and hermetically sealed, after which the cans are subjected to water heated to a high temperature and under pressure. Fish may be (1) plain boiled or steamed; (2) preserved in oil; or (3) prepared in vinegar sauces, and spices. Among the more important fishery products canned are the salmon, sardine, crabs, and oysters.
Special Fisheries. The Sturgeon. Sturgeons are the objects of rather extensive fisheries in both Europe and America; in China they are also important. In Europe the Russians lead in the sturgeon fishery. In the United States the industry is of comparatively recent origin, but is already rapidly declining because of the exhaustion of the supply through indiscriminate fishing. In the United States sturgeon are taken principally by the gill-net and set lines, though many are also taken in pound-nets and seines. The flesh is almost exclusively prepared by smoking, and in both Europe and North America the roe is prepared into caviar. The swim-bladder is used for isinglass; oil is obtained, and the refuse is used as a fertilizer. The annual yield of smoked sturgeon in the United States for 1897 was about 4,000,000 pounds, with a value of $720,000. In 1898 the yield of caviar from the sturgeon in the United States was about 2800 kegs, containing from 125 to 160 pounds each, valued at about $225,000. The first value, annually, to the fisherman is about $300,000. In Russia the value of caviar obtained amounts to nearly $1,500,000 annually, which is mainly marketed in Southwestern Europe.
Herring. Under the head of herring fisheries may be considered all the clupeiform fishes, such as shad, herring, alewife, sardine, and menhaden.
The true herring, or sea herring (Clupen harengus), is undoubtedly the most important food-fish in existence, although in the United States its importance is much less than that of many other species. The total annual catch for the world has been estimated at about 1,500,000,000 pounds, the greater part of which is taken in Norway. The annual catch in the New England States is about 55,000,000 pounds, with a first value to the fisherman of $350,000. The herring are principally taken with seines, gill-nets, and weirs. They appear in the markets in three principal forms, namely, fresh, pickled, and smoked. In the United States there are annually frozen about 25,000,000 herring, with a market value of about $300,000. About one-third of these are used as bait for cod; the remainder are consumed as fresh food. They thus afford an excellent fresh-fish food at seasons when other fresh fish are difficult to get. The quantity of herring prepared in pickle is greater than that of all other species combined. Over 3,000,000 barrels is the annual product for the world, of which only 30,000 barrels are now prepared in the United States, a quantity much exceeded in former years. They appear in the markets in two principal forms—‘round’ and ‘split.’ In the former they are salted without, the removal of gills, heart, and viscera, while in the latter they are eviscerated. The annual production in the United States of smoked herring in various forms is valued at about $285,000. They are prepared for the markets as ‘hard’ or ‘red’ herring and ‘bloater’ herring, the latter being a form and term used mainly in England, and originating chiefly at Yarmouth. The former differ from the latter in being subjected to the smoke at a lower temperature and for three or four weeks, while the latter are smoked at a comparatively high temperature, and only for two and a half
