and valuable in the United States. The principal groundfishes are haddock rosefish, flounder, cod, whiting, pollock, and hake. The fishery yields a catch of 500 to 600 million pounds annually, worth over $30,000,000 to fishermen.

This country is but one of a number of nations drawing from the_North Atlantic groundfish resource. Fishermen of Canada, Newfoundland, France, Portugal, and Spain, collectively take even more than the United States catch. From 80 to 90 percent of the United States catch is marked as fresh or frozen fish. Small quantities are salted or smoked. A canning industry has been growing, producing canned fish cakes, fish balls, fish chowder, canned finnan haddie, and canned smoked halibut. Filleting waste has been used for making canned pet food, and also fish meal and oil. Another important byproduct made

from ground fish is liver oil.

North Atlantic ground fish can live only in food-rich, cool water, on the Continental Shelf and are thus confined to depths shallower than 100 to 150 fathoms. Beyond those contours, the bottom deepens rapidly to 1 or 2 miles; the water becomes too warm, too barren, and otherwise unsuitable for them. The area available to them, however, is vast. The banks inhabited by these ground fish populations range 1,000 miles from Long Island to Newfoundland and are 260,000 square miles in area, which is as large as all the coastal States from Maine to North Carolina.

Tides and currents are violent in this area, but the pattern of the latter is favorable to keeping the ground fishes' drifting eggs and larvae on the banks in areas conducive to survival. Extreme temperatures vary from near to freezing in winter to something over 68° in summer, but in the most favorable and thickly populated parts of the New England banks, they range from about 38° to 55°. Groundfish catches are nearly twice as large during the spawning seasons and summer as in winter, probably because the fish then school more densely to spawn and to feed.

Few species of groundfish have been proved to be overfished to the point of "depletion." True, many of them have become scarcer in certain localities, but this fact is not necessarily alarming, for in a new fishery some reduction in the catch usually occurs after the accumulated stocks are caught off. Among populations that have become seriously reduced is the halibut, which has declined faster than any other Atlantic fishery resources in the last 50 years, as a consequence of the intensive fishery. Likewise the haddock stock of the New England Banks is demonstrated to have been severely reduced by intensive fishing. Other species, among them rosefish and blackback and yellowtail flounders, are probably being fished up to or beyond their most productive level.

Unfortunately, not enough facts are known about the biology of most of these fishes, or about the changes in their populations, to provide the basis for good management. Yet it is growing increasingly clear that only by using sound fishing practices will the fishing industry get the most that this resource can yield. One of the most difficult and important biological problems, in this connection, is to determine what the maximum spawning stock should be, and to devise practical measures that will insure it without unnecessarily restricting the fishery.

Haddock is the mainstay of the United States otter trawl fishery and is the most valuable of all the North Atlantic coast fisheries. At peak production in 1929 the haddock resources yielded nearly 260,000,000 pounds. Owing to reduced abundance brought on by intensive fishing, the average prewar catch was down to about 150,000,000 pounds a year, worth nearly $12,000,000 at recent prices.

Over 90 percent of the catch of haddock is by otter trawls, the remainder mostly by line trawls. Small amounts are also taken with anchored gill nets. Most of the haddock is sold as fresh or frozen fillets, some as cleaned fresh fish. Close to a million pounds are smoked and sold as finnan haddie; in addition, 2,000,000 pounds of this product are imported from Canada each year. Some haddock is canned as fish flakes and some as fish chowder.

The haddock of the Northwest Atlantic make up a complex of populations, of which at least three main groups are recognized, inhabiting, respectively, the New England Banks, the Nova Scotian Banks, and the Newfoundland Banks. The fish vary between groups as to growth rate, spawning time, migratory habits, fluctuations in size of stock, and other biological features. Knlowledge about these populations is growing as United States Fish and Wildlife fishery investigations progress, but is still incomplete.

Haddock spawn for the first time when 3 or 4 years old and 2 to 3 pounds in weight. The spawning schools gather during February to April or later in favorable areas on the banks, usually where the water is from 30 to 60 fathoms deep. The eggs are spawned into the surrounding water, are fertilized there, and drift passively in the currents while they incubate.

They hatch in 2 to 4 weeks, and the larvae, and subsequently the young fish continue to drift for 2 or 3 months before beginning their bottom existence. I adverse currents carry the drifting young to areas where the water is too deep o conditions are otherwise unsuitable, the young perish. The most importan nursery grounds in the New England Banks are on Southeast Georges Bank a 50- to 60-fathom depth. Haddocks' migrations during their first year are very limited but increase as they grow older and larger.

The haddock populations on the New England and Nova Scotian Banks are to a great extent independent of each other, for there is no considerable exchange between these banks of haddock eggs or of young haddock, either during their drifting stages or during the first years of their life on the bottom. Occasional and limited migrations between these banks have been observed for older fish. Tagging experiments and other evidence indicate that the haddock found along the coast of Maine during the spring and summer come mostly from Georges Bank, so that success of the Maine fishery is dependent on the size and condition of the haddock population on Georges.

The haddock catch has declined in spite of improvements in fishing gear, because stocks of fish on the banks have become reduced by heavy and destructive fishing to the point where there are to few spawning fish. Fish and Wildlife Service studies show that at present only about a third as many marketablesized haddock live on the New England Banks as during earlier years. They also show that the fleet is now taking many more small fish than formerly. The number of haddock caught weighing less than 2 pounds made up 9 percent of the catch in 1928, 47 percent of the catch in 1941.

Discovery of the effect of these changes on the haddock stock and its continued productivity has been an important outcome of Fish and Wildlife Service investigations on haddock. Outstanding conclusions of these studies is that the spawning stock of haddock should be nearly double its present size to provide for an adequate production of young. Fish smaller than 2 pounds should be left in the ocean to take advantage of the growth period of their lives. This measure alone would increase the catch by 15 percent or more In rebuilding the haddock stocks, the goal should not be to achieve the tremendous numbers found in the early days, for it has been demonstrated that when the adults are too numerous they seriously compete with the young for food, causing a heavy juvenile mortality.

The catch of haddock from the New England banks can be increased about 50,000,000 pounds or more by protecting fish smaller than 2 pounds and maintaining the spawning stock at the required level. It is believed this could be accomplished by adopting recommended changes in the otter trawl nets and by establishing a minimum commercial size. Some fishermen, boat owners, and dealers have volunteered to cooperate in adopting these proposed measures, but observance has been neither universal, uniform, nor constant, and results have not been satisfactory.

The Fish and Wildlife Service has carried on studies of the haddock resource for several years, chiefly on Georges bank. Conclusions indicating how the yield may be increased need now to be tested, improved in accuracy, and extended to other banks. This requires survey work at sea to determine the distribution and magnitude of unfished stocks of haddock, to study the young before they reach commercial size, to further investigate young-fish-saving gear, and to improve the accuracy of measuring the sizes of the populations and of individual year broods.

The pollock, often called Boston bluefish, has increased in importance in recent years. Just before the war about 38,000,000 pounds were caught annually, about 67 percent of it with otter trawls, about 25 percent of it with anchored gill nets, the rest with purse seines, lines, floating traps, and pound nets.

Pollock is prepared as fresh and frozen fillets, is salted, and a small amount is smoked. It makes a good dry salt fish, though the color is not as white as dried cod. In the last few years some pollock has been canned commercially as fish flakes.

Important as the species is to the United States fishing industry, we know little about its biology, or extent of the resource in American waters.

Pollock spawn off the mouth of Massachusetts Bay, from October through February. The egg is buoyant, and is slightly less than one-twentieth of an inch in diameter; it hatches in 6 to 9 days, depending on temperature, and the larvae are less than one-fifth of an inch long. The young drift near the surface for several months, then gradually settle to the bottom. In the Bay of Fundy, pollock average 5 to 6 inches by the the second spring and about 12 inches by the third

spring. By the fourth summer, that is at 31⁄2 years of age, the fish are from 14 to 181⁄2 inches long. The growth rate in the Gulf of Maine and along the Massachusetts coast is not known.

The cod resource, perhaps the largest of the North American banks, yields a billion pounds of fish a year to fishermen of the United States, Canada, and Newfoundland. In the last century when salting was the only economical way of preserving fish for widespread distribution, the cod supported the largest fishery of the United States because it salts particularly well. The development of refrigeration and of the filleting industry, however, brought the haddock into prominence in the 1920's since haddock were more plentiful on the nearby grounds and more suitable for filleting than cod; and because the demand for salt fish was declining in this country, cod became less sought after by the United States fishermen. Today the annual catch is around 95,000,000 pounds.

The biggest part of the United States catch of cod is taken with otter trawls; the balance with lines, sink gill nets, floating traps and pound nets. Most cod is marketed as fresh and frozen fillets and steaks, and a small quantity is salted and smoked. The skins from the salted fish are made into a high-quality glue. Liver oil made from the livers of haddock, cod, hake, pollock, etc., is one of the principal sources of vitamind D. It also has a number of industrial uses.

Cod live in much the same depths and on the same type of bottom as haddock, but whereas the latter is the dominant species (in bulk at least) on Georges bank, cod becomes increasingly dominant off Nova Scotia and exceeds any other bottom fish on the Newfoundland banks and beyond. Cod spawns over a wide area from the Newfoundland banks eastward. The heaviest concentrations on the New England coast are found on eastern Georges bank, in the same localities as haddock but somewhat earlier in the season. The greatest number of yearling cod have been found on southeast Georges bank in somewhat deeper water than the older fish. On Georges bank young cod grow to about 71⁄2 inches in their first year, and reach 15 to 16 inches at 2 years of age. Growth on the Nova Scotian banks, which are farther north, is slower than on Georges bank. Cod grow to enormous size, the largest recorded specimen measuring over 6 feet long and weighing 211 pounds. However, the commercial catch is made up principally of fish weighing 21⁄2 to 25 pounds.

It is not known to what extent the cod populations found in the Gulf of Maine, on Georges bank, and on the eastern banks are independent, but these fish are known to move about more than haddock. The catch per day's fishing has varied widely over the past 10 years. It is not known whether these variations reflect changes in the population, migrations, or a shifting of the primary objective of the fishery between haddock and cod. An understanding of measures needed to obtain maximum utilization of this resource must await basic study of the cod populations and the conditions which govern their yield.

The rosefish or redfish supports a fishery that has grown spectacularly in recent years. In 1933, when only 264,000 pounds were caught, it ranked one hundred and thirtieth in volume of production among the United States fisheries. In 1946 about 180,000,000 pounds were caught, which ranked it first in volume among New England fishes. This remarkable growth came as a result of the development of new markets and utilization of the rosefish by the filleting industry. Practically the entire catch is taken by otter trawls in depths of 50 to 125 fathoms. Fishing is carried on throughout the year, but only during daylight hours, for the fish scatter or rise off the bottom at night.

Rosefish is one of the few commercial species giving birth to live young instead of eggs. The young are spawned from June until September and are abundant at or near the surface throughout the summer. The fish grow slowly at a rate of about an inch a year until around their eleventh year, when they mature. Little is known about their migrations, but there is some evidence that the larger fish move about over considerable distances so that an intensive fishery on one ground will affect the rosefish populations on others.

The rapid expansion of the rosefish fleet and catch has resulted in a considerable decline in the yield from the nearby grounds as the accumulated stocks of older fish were caught. In order to supply the market the fleet has expanded operations to progressively more distant grounds and is concentrating to an increasingly greater extent on small fish. The Fish and Wildlife Service has recently begun a study of the effect of these developments on the productivity of the rosefish resource. It is working to develop practical measures which will protect the smaller fish and otherwise provide conditions necessary for the maximum continuous yield from this fishery.

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Ocean pout is very abundant locally, both inshore and on the outer banks. Ordinarily very small quantities of this species are landed, but wartime demands stimulated the landing of 3 to 4 million pounds by otter trawlers in 1943 and in 1944. Most of this quantity was taken from February to May close to New Bedford and Provincetown, Mass., and a large part of its was filleted. In 1945 the catch declined to less than 500,000 pounds; in 1946 it amounted to only 410,493 pounds.

Whiting or silver hake are taken commercially from Sable Island to South Carolina. In the Gulf of Maine they are a summer fish, appearing first in the Cape Ann-Massachusetts Bay region in March and becoming increasingly abundant as the waters warm. Off Long Island, they are common throughout most of the year, being taken offshore by otter trawlers from November through March, and inshore by pound netters from April through July. Off North Carolina they are caught in the winter trawl fishery. They are also caught with floating traps, anchored gill nets and even in purse seines. Otter trawlers, particularly of the Gloucester, Boston, and Provincetown fleets, have taken increasing amounts of whiting, and the catch has consequently risen from 14,000,000 pounds in 1930 to 50,000,000 pounds in recent years.

The bulk of the catch is cleaned and skinned, then frozen and packaged; it is sold as pan-dressed, split, or filleted whiting. It is popular in the Middle West, especially Kansas City, where it is used in fried-fish sandwiches. Before the war some whiting and waste from filleting and skinning was canned for pet food.

Nothing is known regarding the extent of the population, the rate of growth, or the size at maturity of whiting, nor are more than fragmentary data available regarding nursery grounds. Whiting spawn from June through September. The eggs and subsequently the larvae drift in the urrents. The young fish descend to bottom probably when 1 to 11⁄2 inches long. Whiting are found on sandy and pebbly bottoms from the shore line to a depth of about 300 fathoms. Fishermen report that this fish is becoming scarcer, with former highly productive grounds now barely furnishing a day's fishing.

Hake is a name applied to several species of closely related fishes found from Newfoundland to Cape Hatteras. Two of these are taken commercially: the white hake, which, until very recently made up almost the entire catch, and the red hake, which had remained unutilized until wartime shortages created an unusual demand for fish in 1943 and 1944. Something over 25,000,000 pounds of hake were caught in 1945, principally with otter trawls. In that year fishermen took about 15,000,000 pounds of red hake. In the following year the catch of this species declined to about one million pounds. Hake is sold fresh, frozen, salted, dried, and as smoked fillets. The air bladders are dried and used for making isinglass; the livers are collected for vitamin oils.

White hake grows to 20 to 30 pounds, but the average-sized fish landed is 5 pounds or less. Red hake average a pound to two, and, though of good flavor, are so soft-bodied do not keep well. Very little is known of the biology of hakes or about the extent to which the supply is being utilized. The fishery for both of these species could probably be expanded if the market warranted.

The cusk is a member of the cod family and is taken in deep waters of more than 60 fathoms, the catch usually being incidental to cod fishing. Unlike most other bottom fishes, it does not school but is of solitary habit. The cusk is more important in European fisheries than it is likely to become on this side of the Atlantic, where it has never been abundant.

United States fishermen in 1940 took nearly 8,000,000 pounds of cusk. However, the production has declined to about one-fourth of the 1940 catch. Most of the catch is made off the New England coast during the winter and spring, with small quantities landed at other seasons. In 1944 more than 90 percent of the catch was made with line trawls; the balance with anchored gill nets, otter trawls, and hand lines. In recent years the number of line trawlers has declined, and the major portion of the catch is now made by otter trawlers.

Although the cusk may grow to a length of 3 feet and a weight of 30 pounds, the commercial catch consists mostly of fish 12 to 2 feet in length averaging 5 pounds or so in weight.

Some cusk

The cusk is marketed largely as fresh and frozen sticks and fillets. fillets are smoked and sold as "finnan haddie." Until World War I, almost the entire catch was salted: A small amount is still preserved in this way.

Very little is known about the biology of the cusk on the New England coast, and practically nothing about the size and extent of the cusk populations and potential catch.