The word mackerel is a common one in every day conversation. Everywhere we can hear such expressions as, "holy mackerel," "dead as a mackerel," and "cold as a mackerel." Undoubtedly the fish called mackerel, from which these terms have arisen, must be universally popular and well known. It is hoped that the following pages will give some idea of the popularity and economic importance of this fish.

The irregular habits and the unheralded periods of scarcity or abundance of the common Atlantic mackerel are subjects of great concern to the fishermen of Europe and America. The occasional failure of the mackerel to appear spells hardship and privation for many fishermen and dealers, and when its does appear in the vast shoals that are eagerly awaited each spring, adverse economic conditions sometimes prevent the fishermen from making a living. In California the mackerel is always present, summer and winter, year in and year out, but because of economic factors the fishery is subject to sudden ups and downs.

As might be expected, the habits of the Atlantic mackerel have long been the subject of speculation and study, both by fishermen and scientists. Many stories are current about how the mackerel spends the winter, the time when it is absent from the Atlantic coasts of Europe and North America. One of the most common stories is that the fish bury themselves in the mud at the bottom of the sea and that during this hibernation a film comes over their eyes so they are rendered blind. Some people claim that the mackerel go into the Arctic Ocean to spend the winter; others say that they go south into the tropics. The only certain fact is that nobody really knows where the majority of the mackerel spend the winter and that one guess is as good as another.

Mackerel occasionally appear in shoals so dense and extensive that the ocean is colored with them for miles. At these times it is said to be dangerous to enter the water. A story is told of a Norwegian fisherman who fell overboard into a school of mackerel and was torn to pieces by the savage fish before his comrades could pull him out. This story is probably somewhat exaggerated, but the thought of that luckless fellow would suffice to keep most people from diving into a swarm of hungry mackerel.

The idea has arisen in some places, notably Australia, that the flesh of the mackerel and mackerel-like fishes is poisonous. As a matter of fact, no food is more wholesome than fresh or properly preserved mackerel, tuna or bonito. However, all these fish spoil readily if not cared for, and stale fish can cause illness, and the illness can cause stories about poison.

The scombroid or mackerel-like fishes are of very great commercial importance throughout the world. The four most important groups of fishes are those comprising the herring, salmon, codfish and mackerel families. Of the mackerel family, the two mackerels (Scomber and Pneumatophorus) are among the most widespread and universally important, although the tunas, bonitos, seerfishes, and Spanish mackerels help to keep the family Scombridae in a leading position.

The fishermen of nearly every maritime nation in the temperate zones catch mackerel in large numbers. The annual catch (1928–1929) off the North Sea and Atlantic coasts of Europe amounts to 100,000,000 pounds. The fishermen of the Atlantic coast of North America catch 40,000,000 to 60,000,000 pounds of mackerel every year (1924–1930). The California fishery accounts for 15,000,000 to 60,000,000 pounds annually (1928–1931). Japan, with an annual (1923–1925) catch of about 150,000,000 pounds, is the largest consumer of mackerel in the world. In addition to the foregoing, there are important mackerel fisheries in the Mediterranean and Black seas, and lesser fisheries in Australia, New Zealand and South America.

The mackerel is everywhere primarily a fresh fish, that is to say, the greatest part of the world catch is consumed in a fresh state. Nevertheless, really enormous quantities are canned, salted or dried in many parts of the world. The canning industry is a recent development, dating back no farther than the nineteenth century. Salting and drying, however, are ancient methods of preserving fish so they can be sent to distant markets or held over from periods of abundance to times of scarcity. Before modern refrigeration methods made possible the transportation or holding of fresh mackerel in quantities, salted mackerel was by far the most important product of the world's mackerel fishery.

The mackerel is one of the leading commercial fishes of California; its catch is exceeded only by that of the sardine. However, for many years prior to 1928, the fishery based on the Pacific mackerel, Pneumatophorus diego, was relatively unimportant. Since the turn of the century the mackerel had supplied a steady but limited demand for fresh fish, but at no time was any appreciable part of the great number of mackerel in the ocean utilized. In 1928 the first large scale canning of mackerel took place. The subsequent development of the mackerel canning industry provides one of the most spectacular pages in the history of the world's fisheries. Almost overnight the mackerel catch rose from tenth to second place among the fisheries of California.

Today ever-expanding fishing operations are endangering the supply of mackerel. In the not too distant future it will be necessary to impose restrictions on the industry so that it can continue to exist. At present there is no legislation in California pertaining to the mackerel specifically. Such legal protection as it receives consists of general gear restrictions, the establishment of areas closed to all commercial fishing, and the application of general laws prohibiting the waste of fish or the manufacture of fish into meal and oil.

The mackerel fishery, being new and still growing, is changing rapidly. Differences in gear and in boats are to be noted during the first few years of its development. It is the purpose of this paper to present a study of the fishery during its formative period, with particular emphasis on the boats comprising the mackerel fleet, in order to facilitate direct comparisons in future years. In this connection it can be said that the present account is a sequel to the general report issued as Fish Bulletin 40 (Croker, 1933). In the brief interval since the publication of that paper, a number of developments have taken place in the industry, illustrating the changing character of this fishery.