The Cod Family andIts Utilization

JOHN J. RYAN Figure I.-Atlantic cod.

Table 1.-World commercial catch of fish by species groups, 1973-76.

Catch (1,000 t)

Introduction

Spanish explorers came to the NewWorld to find gold and precious stones,but the French and Portuguese, fol­lowed by the English, crossed the At­lantic to catch fish, especially the Atlan­tic cod, Gadus morhua. In the 16thcentury, French and Portuguese vesselsfished the Grand Bank off Newfound­land. By the early 17th century, theNew England colonists were fishing forcod (Fig. 1) in the local waters. In 1624"not less than 50 vessels from Glouces­ter" fished with handlines off the coast.In 1748, the first catch of cod fromGeorges Bank was landed.

Cod probably has influenced thecourse of American history more thanany other marine fish. It's white flakyflesh was the foundation of power andwealth in colonial America. Cod was toyoung America what coffee was in re­cent years to Brazil; it was the firstproduct shipped out of colonial Mas­sachusetts. A large wooden codfishcarving was hung in the MassachusettsState House in 1784 and is still occupy­ing an honored position there.

As a commercial fish, cod had nopeer: It was abundant all year. Whensplit, salted, and dried, it kept almostindefinitely in any climate. Many longvoyages could not have been possible

without dried cod, for ships could carryno perishable food as staples.

The cod family, from an economicpoint of view, is the most important ofall the families of fishes. The membersof the cod family are second only to theherring family in volume of commer­cial landings (Table 1). In contrast tothe herring family, which is often usedfor industrial purposes, almost allof the cod, haddock, hakes, and whit­ings are used for human food. In1976, 12,116,000 metric tons (t)(26,710,000,000 pounds) of the codfamily were landed worldwide ascompared with 15,089,000 t(33,196,000,000 pounds) of the her­ring family (Food and Agriculture Or­ganization,1976).

Classification

Twenty-five species of fishes in thecod family, Gadidae, are listed by theAmerican Fisheries Society (Bailey etaI., 1970). They include the following:1) Toothed cod, Arctogadus borisovi;2) polar cod, Arctogadus glacialis; 3)Arctic cod, Boreogadus saida; 4) saf­fron cod, Eleginus gracilis; 5) Pacific

cod, Gadus macrocephalus; 6) Atlanticcod, Gadus morhua morhua; 7) Green­land cod, Gadus ogac; 8) cusk, Brosmebrosme; 9) fourbeard rockling, En­chelyopus cimbrius; 10) burbot, LotaIota; 11) haddock, Melanogrammusaeglefinus; 12) silver hake (whiting),Merluccius bilinearis; 13) Pacific hake,Merluccius productus; 14) longfinhake, Phycis chesteri; 15) luminoushake, Steindachneria argentea; 16) redhake, Urophycis chuss; 17) Gulf hake,Urophycis cirratus; 18) Carolina hake,Urophycis earlli; 19) southern hake,Urophycis fioridanus; 20) spottedhake, Urophycis regius; 21) whitehake, Urophycis tenuis; 22) Pacifictomcod, Microgadus proximus; 23) At­lantic tomcod, Microgadus tomcod;24) Atlantic pollock, Pollachius vir­ens; and 25) walleye (Alaska) pollock,Theragra chalcogramma.

Although European ichthyologistsseparate the hakes and the cods becauseof differences in the structure of theskull and ribs, some American expertsgroup them into a single family, andthey are so listed by the AmericanFisheries Society.

Species group 1973 1974 1975 1976

Source: "Yearbook of Fishery Statistics, 1976," FAD, Rome, Vol. 42.

8,4457,3894,950

15,08912,1169,532

13,888 13,61812,699 11,8829,244 9,599

11,31411,9709,293

Herring, sardines, anchovies, el al.Cods, hakes, haddock, et al.Freshwater fishesMiscellaneous marine and

diadromous fishes 8,676 8,382 8,021Jacks, mullets, sauries, et al. 5,740 5,454 5,935Radlish, basses, congers, et al. 4,320 4,865 5,071

John 1. Ryan is a Supervisory Research FoodTechnologist at the Gloucester Laboratory,Northeast Fisheries Center,. ational MarineFisheries Service, NOAA, Emerson Avenue,Gloucester, MA 01930.

November 1979 25

Figure 2.-Rays and spines.

i--------- SPINES ---

The Cods

The cads, family Gadidae, are soft­finned fish lacking true spines; but inthe whiting, the dorsal and anal fin raysare so stiff as to feel like spines. Thecod family is distinguished from othersoft-rayed fishes (Fig. 2) by the fact thatthe large pelvic fins are situated underor in front of the pectorals and not be­hind them as in salmon and herring.The cads are generally fishes of coldwater, and most of them live close tothe bottom.

Codfish are found on both sides ofthe Atlantic Ocean, in the north PacificOcean, and in the Arctic Ocean down toabout 250 fathoms (457 m). The bestcod fishing grounds are offshore banksincluding Georges Bank 150 miles (240km) off Boston, Mass., and GrandBank off Newfoundland where moderntrawlers may take 35 tons of cod in onlya few hours of fishing.

The most important of the cads is theAtlantic cod, which includes severalgeographical subspecies. These are theBaltic cod, Gadus morhua callarias,found in the Baltic Sea and parts of theNorth Sea; theKildin Island cod, Gadusmorhua kildinensis, which lives in a saltpond, Lake Mogilno, on an island in theBaltic Sea; and the White Sea cod,Gadus morhua marisalbi, found in theArctic Sea. The Greenland cod, Gadusogac, often considered a separatespecies, is found mostly in inlets and inthe shallow water of the Arctic Oceanfrom West Greenland to Point Barrow,

26

, ,-------:-- -_.- RAYS- --1

I II II II II II II II II II II II II I

IIIIIIIIII

.,."'.. I0~ I.X I

Alaska. Additionally, the Pacific cod,Gadus macrocephalus, is consideredby most taxonomists as a separatespecies.

Atlantic Cod

The Atlantic cod lFig. 1) is oval incross-section with three distinct dorsalfins, two anal fins, and a nearly squaretail. Its color varies from olive green toreddish brown depending on thebackground of its habitat. The lateralline is white, and the skin has manysmall scales. Most cod average about 3feet (0.9 m) in length and weigh from10 to 25 pounds (4.5 to 11.3 kg).

A giant cod was caught by commer­cial fishermen off the northern Mas­sachusetts coast on a Iine trawl in May1895 (Jordan and Evermann, 1902). Itmeasured over 6 feet (1.83 m) in lengthand weighed 21114 pounds (95.8 kg).This was an old fish, but no one knowshow old.

The cod is found on both sides of theNorth Atlantic Ocean and Arctic Oceandown to about 1,500 feet (457.2 m).Although the cod is a demersal or bot­tom-living fish, when in search of foodit may be found near the surface. Itprefers rocky, pebbly, or sandy bot­toms, and water temperatures from 32°to 500f (0° to lO°C).

The adult cod feeds mostly on small­er fish such as sand eels, Ammodytessp.; capelins, Mallotus sp.; herrings,Clupeidae; and other small cod, and/orshellfish such as shrimp, mussels,

clams, crabs, and squid. When hungry,it will eat almost anything such as falseteeth, old boots, and pieces of wood. Attimes, it eats small floating molluskswhich cause its flesh to exhibit a strongodor of iodine when cooked.

Cod migrate principally because ofchanges in the temperature of the water,better availability of food, and thesearch for suitable spawning locations.

Growth rates differ from ground toground, but the cod is a relatively fastgrowing fish and can theoretically liveto an age of 50 years. A I-year-old codis usually about 7 inches (17.8 em)long; a 2-year-old will be about 14inches (35.6 cm); and by the end of thethird year, the cod is about 22 inches(55.9 cm) long. Growth is slower incolder waters. Cod in Arctic watersreach maturity in 6-8 years at 6-8 inches(15.2-20.1 em) in length.

The cod is one of the more prolificfishes. It has been calculated that if allthe eggs spawned by all female cod inone spawning season were to survive,the oceans would be one mass of cod(Jensen, 1972). One female cod mayrelease from 3 to 7 million eggs at atime. A 75-pound (34.0-kg) female codcan produce 9.1 million eggs. Spawn­ing takes place in shallow (5-25fathoms or 9.15-45.7 m) waters usuallyin the early spring. The eggs arebuoyant and transparent without oilglobule and 1/20-1/ 16 inch (1.27-1.59mm) in diameter. At 43°F (6.2°C),hatching may be expected in 14 or 15days. The newly hatched larvae feedmainly on plankton and drift with sur­face currents. When the larvae havegrown to a length of about 3 inches (7.6cm), they move to the ocean bottomwhere they feed on worms and smallshrimps. Only a few eggs out of themillions spawned will survive and be­come mature fish.

Pacific Cod

The Pacific cod, Gadus macrocepha­lus. (Fig. 3) is also known as cod, truecod, and gray cod. In appearance andhabits, it resembles its cousin, the At­lantic cod. In 1976, close to11.900,000 pounds (5,400 t) of Pacificcod were landed in the United Stateswith a value of $1.5 million (Robinson,

Marine Fisheries Review

Figure 4.-Polar cod.

Figure 3.-Pacific cod.

pointed first dorsal fin is different fromthat of other relati ves.

Haddock are found in the North At­lantic Ocean along the coasts of New­foundland, Nova Scotia, and the Gulfof Maine, and on Georges Bank, 150miles (240 km) east of Massachusetts.In the northeast Atlantic, it is found offthe coast of northern Europe, theBritish Isles, and Iceland. Haddock arebottom dwelling fish in areas wherewater temperatures range from 35° to48°F (1.7° to 8.9°C). They are usuallycaught on an ocean bottom that is ofhard, smooth sand; gravel; or brokenshell. They like smooth areas betweenrocky patches.

Haddock in the Gulf of Maine spawnfrom late February until May with apeak in March and April. The haddockis a prolific fish for its size; a single fishmay produce from 150,000 to1,000,000 eggs. A 19V2-inch (0.5-m)female produces 169,000 eggs; a 24­inch (0.6-m) one, 634,000 eggs; and a28Y<l-inch (0.7-m) one, 1,840,000eggs. Spawning occurs near the seabed. The eggs of the haddock are

Haddock

The most valuable member of thecod family in the United States is thehaddock. Melanogrammus aeglefinus,(Fig. 5). The primary distinguishingmarks of the haddock are the black lat­eral Iine and sooty black shoulderblotch called the "Devil's thumbprint" or "St. Peter's mark." Also, the

Greenland Cod

The Greenland cod, Gadus ogac, isvery similar to the Atlantic cod, Gadusmorhua morhua, in form, but it lacksthe distinguishing round spots of theAtlantic cod, and its lateral line is notaccompanied by a light longitudinalstripe on the tail as is the Atlantic cod. Itgrows to 28 inches in length and rangesfrom west Greenland, west to PointBarrow, Alaska, and thence along theArctic coast east and south to theMiramichi estuary, Gulf of St. Law­rence, and Cape Breton Island (Hart,1973). Its commercial importance isindicated by a catch of 4,642 t in 1975(Table 2).

Polar Cod

The polar cod, Boreogadus saida,(Fig. 4) normally grows to only 6-8inches (15.2-20.3 cm) long, but maygrow to 15 inches (38.1 cm). It resem­bles the pollock and is found in theArctic Ocean from Greenland toSiberia. It is circumpolar, traveling theWhite Sea to Spitzbergen to Iceland,Greenland, Canada. Alaska, etc. Thepolar cod is generally not consideredimportant for human food. It may bedistinguished from related species by aforked tail and slender body (Leim andScott, 1966).

A cousin, the Arctic cod,Arctogadus glacialis, is being fished bythe Norwegians for meal and oil but isof Iittle importance as a food.

1977). The 5-year average was9.200,000 pounds (4,170 t) comparedwith 56,000,000 pounds (25,100 t) ofAtlantic cod. Its head is large (i.e.,macrocephalus), and it has three dorsaland two anal fins. Its color is brown togray on the upper surfaces and white onthe anal and caudal fins with manybrown spots on the back and sides. Itgrows fast, reaching an average lengthof 3 feet 3 inches ( I m) and a weight of35 pounds (15.9 kg) in 2 to 3 years.

Pacific cod are found in the NorthPacific Ocean from California to north­ern Alaska and in a great arc to Korea.Spawning takes place in winter or earlyspring, although the spawning groundsare relatively unknown (Hart, 1973).As many as half a million eggs may beproduced by each female and they hatchin 8 or 9 days at 52°F (11°C). Theyoung fish usually migrate northward tothe colder waters of Washington, Ore­gon, or Alaska. They mature within 2-3years with an 8-9 year life span (Hart,1973).

The Pacific cod's white flesh has amild flavor and flakes easily. It is mar­keted as fresh and frozen fillets withsome of the catch sold as whole freshfish. The early Pacific cod fishery washandicapped by false rumors by ewEngland dealers that it was not a truecod and that it was an inferior fish thatwould not keep. Upon completion ofthe transcontinental railroads, marketswidened.

November 1979 27

Source: Food and Agriculture Organization of the United Nations, 1976.

Figure 5.-Haddock.

Table 2.-World commercial catch of cod family, excluding hakes, Inthousands of metric tons (live weight).

Atlantic Pollock

The Atlantic pollock, Pollachius vi­rens, (Fig. 7) also known as pollock, isanother cod relative. It is dark greenishin color and usually olive or greenishgray with silver tints on the lower side.A light lateral line extends the length ofthe body and is in contrast to the darksides. It has a spindle-shaped stream­lined body with a forked tail. The aver­age size is 2-3 feet (61.0-91.4 cm), andthe average weight is 4-12 pounds(1.8-5.4 kg) (Bigelow and Welsh,1925). Large pollock feed on other fishwhile the smaller ones feed on crusta­ceans.

The pollock is seldom taken at above500f (10°C) temperatures. Most of thepollock are caught in mid-water usinghigh opening trawls. It is one of themost active members of the cod family.It occurs in large. schools that may befound at any level between the surfaceof the water and the bottom.

The pollock spawns in late fall andearly winter. Large pollock may pro­duce over 4 million eggs, although theaverage number is about 22,000. Thebuoyant eggs hatch in 6 days at 50~

feet (3.0 cm) long, 4 feet (1.2 m) wide,and 4 inches (10.2 cm) thick-that arerigged ahead of the net on towing warpsin such a way that they behave likekites. The catch accumulates in a bag atthe narrow cod end. The size of netdepends upon the size and power of thevessel and the design of the gear. Somehaddock are also caught with longlines,fish traps, and gill nets.

Landings of haddock in the U.S. dur­ing 1976 were only 12.8 million pounds(Robinson, 1977). From 1924 to 1966,the haddock fishery never yielded lessthan 100,000,000 pounds (45,000 t).Landings for a 5-year average for had­dock (1971-75) were 13.2 millionpounds.

Haddock are caught, handled, andprocessed about the same as the Atlan­tic cod. The haddock is used to make anumber of smoked fish products such asfinnan haddie and other cold smokedproducts such as the golden cutlet andthe smoked single fillet. The chemicalcomposition of haddock flesh is similarto that of cod.

37,295

4,642

24,496

68,900

203

63,162

54,313

12,244

695,388

529,132

680,101

166,955

5,023,925

271

9,782

14,100

45,863

25,067

67,328

3,391

895,499

581,488

716,411

125.188

161,533

3,900

400

25,700

50,200

70,800

1,000

11,400

82,200

500,400

662,800

624,900

150,700

ches (31.1 cm), and a 3-year-old had­dock, 17 inches (43.2 cm). The had­dock seldom grows longer than 36inches (91.4 cm) in length or weighsover 25 pounds (11.3 kg). The haddockis a bottom feeder. Shrimp, crabs,worms, squid, and, at times, small fishform the diet for this species.

Most of the U.S. haddock catch istaken with otter trawls (Robinson,1977). The otter trawl (Fig. 6) is afunnel-shaped net which is towed overthe sea floor behind a fishing vessel.The mouth of the net is kept open bytwo wooden or steel otter boards- 10

7,300

300

8,000

1972 1973 1974 1975

60,500

50,900

23,100

653,700

525,100

549,200

150,700

167,100

4,213,300 4,617,100 4,907,362

2,742,700 2,540,000 2,811,495 2,422,131

Species

Atlantic codGadus morhua morhuaPacific codGadus mac,ocephalusGreenland codGadus ogacPolar codBoreogadus saidaHaddockMe/anog,ammus aeg/elinusPollockPol/achius vi,ensAlaska pollockTherag,a chalcog,ammaLingMolva molvaBlue lingMolva dypterygiaNorway poutT,isopterus esmarkiiBibTr;sopterus JuscusBlue whitingMicromesistius poutassouAtlantic torncodMic'ogadus torncodGrenadierMac,ourus spp.

buoyant and are found near the surfaceof the sea. Haddock eggs hatch in 13-24days at 41°F (5°C), and the larvae areabout 3/16 of an inch (4.8 mm) long anddrift with the current. The tiny haddockare nourished at first by the egg yolkand later feed on zooplankton. At about4-5 months, the young haddock start todescend to the ocean floor where theylive the rest of their lives (Bigelow andWelsh, 1924).

During its first 3 years, a haddockgrows fast. A l-year-old haddock aver­ages 7V2 inches (19.05 cm) in length, a2-year-old haddock measures 12'4 in-

28 Marine Fisheries Review

Figure 6.-0uer trawling.

Figure 8.-Alaska or walleye pollock.

Merluccius gayi. is being sought by aPolish-Peruvian fishing company offthe Peruvian shelf. The South Africanhake, Merluccius capensis, is anotherspecies presentl y under development asan alternate to Atlantic cod. The New

and dressed fish. South American hake,Merluccius hubbsi, is a resource withan estimated stock of 3,000,000 t and apossible yield of 555,000 t per year,offering an alternative to shortages ofthe Atlantic cod. The Chilean hake,

Figure 7.-Atlantic pollock.

(10°C) water temperature. The fishgrows to 5-7 inches (12.7-17.8 cm) bythe end of the first year and usuallyachieves 18 inches (45.7 cm) by the endof the third year.

Small pollock migrate into coastalwaters in the spring and remain allsummer. In the winter, they move todeeper water. Pollock often school atthis time with 80 percent of the landingstaken during October, November, andDecember.

The pollock is similar in flavor, odor,and texture to cod and haddock and isusually marketed in fillet form. Itmakes a good dry sal t fish, and some aresmoked.

Alaska Pollock

The Alaska pollock, Theragra chal­cogramma. (Fig. 8) has become animportant food fish. Pollock blocks ac­counted for 25 percent of all blockimports in 1976. The Republic of Koreawas the principal supplier of pollockblocks (61 percent of the total) followedby Japan (II percent of the total)(Capalbo and Kinoshita, 1977).

The Alaska pollock, low in themarine food chain, feeds on planktoniccrustaceans such as copepods, amphi­pods, and shrimp-like euphausiids.These are concentrated in the nutrient­rich, shallow waters of the continentalshelf and slope. The pollock is usuallymature at 3-4 years when it is about 15inches (38.1 cm) long.

The Hakes

For many years, the hakes were con­sidered to be trash fish. Recent! y,foreign vessels have started to exploitseveral hake species (Table 3) (Fig. 9).These include the whiting or silverhake, Merluccius bilinearis, (Fig. 10);the Atlantic hake, Merluccius albidus.found on Georges Bank and off themiddle Atlantic States; and the Pacifichake, Merluccius productus, found inthe North Pacific Ocean. In the easternAtlantic, a close relative of the silverhake, the European hake, Merlucciusmerluccius. is found. It also occurs offNorth Africa in both the Atlantic Oceanand the Mediterranean Sea.

Large amounts of hake are beingused for the production of fish blocks

November /979 29

o

()

~ EUROPEAN HAKE ~ M. MAGNOCULUS ~ PANAMANIAN HAKE--

II CAPE HAKE rtJJ MERLUZA • PACIFIC HAKE

~ SILVER HAKE ~ M. POLYLEPIS Lill NEW ZEALAND HAKE.....IIIIll OFFSHORE HAKE II CHILEAN HAKE

Figure 9.-Worldwide hake, Merluccius spp., distribution, modified after Cabo(1965). Source: Grinols and Tillman, 1970.

Source: Food and Agriculture Organization of the United Nations, 1975.

Table 3.-World commercial catch 01 hakes, 1972-75, in thousands 01 metrictons.

Zealand hake, Merluccius australis,occurs off New Zealand. The Panama­nian hake, Merluccius angustimanus.is found from southern California toPanama. All species of the hake areslender, streamlined in shape, and dif­fer from other cod species in having twodorsal fins and one anal fin.

Otter trawl is the main fishing gearused for hake, although pound and trapnets are also used. Despite the soft tex­ture, hakes are amenable to mechanicalhandling on ship or ashore.

Whiting

Whiting or silver hake, Merlucciusbilinearis (Fig. 10), are found on the

Species

Silver hake (whiting)Merluccius biNnearisChilean hakeMerluccius gayiArgentine hakeMerluccius hubbsiPacrtic hakeMerluccius productusBenguela hakeMerluccius po/IiEuropean hakeMerluccius merlucciusCape hakeMerluccius capensisSenegalese hakeMerluccius senegalensisRed hakeUrophycis chussWhite hakeUrophycis tenuis

1972

233,000

107,600

139,300

119,600

100

116,500

1,111,300

36,900

76,100

21,200

1973

434,900

223,900

187,500

163,500

100

129,500

892,600

101,700

66,700

18,400

1974

225,625

163,652

199,400

205,786

100

131,666

726,934

102,822

36,334

18,337

1975

230,529

142,593

152,400

230,350

496

136,779

626,751

86,530

32,319

19,810

30 Marine Fisheries Review

continental shelf from Newfoundlandto South Carolina. In winter, these fishmove into deeper water and go furthersouth. Whiting are silvery over thewhole body with brown or dark graytints on the upper surface of the body.They have two dorsal fins and one analfin with no barbel on the lower jaw.They reach a length of about 21/2 feet(0.8 m) and a weight of 5 pounds (2.3kg).

Whiting are lean, firm textured, flakyfish and are very tasty. The two majorU.S. market forms are either headedand eviscerated fish or filleted. A smallamount of the headed and evisceratedwhiting is smoked.

Pacific Hake

Pacific hake, Merluccius productus(Fig. 11), are found from the Gulf ofCalifornia to the Gulf of Alaska andfrom the surface to 491 fathoms (900m). Most Pacific hake are from I to 1.5feet (30 to 46 cm) long with a recordlength to about 3 feet. Their colorranges from gray to dusty brown with abrassy overtone. Because of certaindeficiencies of texture of the flesh, thePacific hake has not commanded a verylarge market. Recent attempts topopularize this fish may result in morewidespread acceptance.

White Hake

Figure 1O.-Silver hake.

Figure 11.-Pacific hake.

Figure 12.-White hake.

Figure l3.-Red hake.

White hake, Urophycis tenuis, (Fig.12) also called Boston hake, is muddycolored or purplish brown on the back.The sides at times are bronze and thebelly is grayish white or yellowishwhite. peppered with tiny black dots.The maximum length is about 4 feet,the weight 40 pounds, but most averageno more than 5-8 pounds. There areonly two dorsal fins (the second is muchlonger than the first), one anal fin, andthe ventral fins are long and narrow. Itis distributed in deep water from New­foundland to Cape Hatteras and is usu­ally found on soft, muddy bottoms. Itfeeds on small crustaceans, squid, andsmall fish (Bigelow and Welsh, 1925).The larger fish are usually marketed asfresh or frozen fillets, while the smallerones are used for animal feed.

November 1979

Red Hake

The red hake, Urophycis chuss,(Fig. 13) usually weighs 1-3 pounds

(0.45-1.4 kg) and seldom measuresover 30 inches (76.2 cm) long. It isreddish in color on the back and sidesand white to yellowish on the belly.

31

Figure 14.-Blue whiting.

Red hake is abundant off the U .S. eastcoast and could be used to produce fishprotein concentrate. A 5-year averagelanding (1971-75) of red hake was2,680,000 pounds (1,220 t) with4,970,000 pounds (2,250 t) landed in1976 (Robinson, 1977).

Red hakes are sluggish swimmerswhich are usually found over soft bot­toms. The young hakes are abundant,close to shore in eel grass beds. Theyfeed on small crustaceans, squid, andsmall fish (Bigelow and Welsh, 1925).Spawning usually occurs from Julythrough September in shoal waters.Red hake grows to 8 inches (20.3 cm)by the end of the first year and 16-19inches (40.6-48.3 cm) by the end of thethird year. Dense schools of red hakemigrate in early spring into shoal wa­ters. Hakes move around less than codand haddock and tolerate a greatertemperature range. Red hake is usuallymarketed as fresh or frozen fillets withthe smaller fish used for mink, cat, andpoultry feed.

South African Hake

The South African hake, Merlucciuscapensis, called stockfish by the SouthAfricans, is a fairly large fish growingup to 4 feet (1. 2 m) in length. It issilvery gray in color with a spot of blackon the inside of its lower front fins.South African hake is a bottom dwellerand is usually caught by trawlers inhuge nets pulled along the sea bottom indepths of 300 fathoms (549 m). Largeamounts of the South African hake aremade into fish blocks which are used forproducing fish sticks and portions.

Argentine Hake

Argentine hake, Merluccius hubbsi,is usually found off the coast ofUruguay during winter (May-June).The schools then concentrate in thesouthern Argentina region (lat. 42° and

32

45°S). It has been estimated that a pos­sible annual yield of 1,200,000,000pounds (555,000 t) could be exported.Most of the production goes into filletblocks, but consideration is being givento boil-in-the-bag frozen products totake advantage of superior packaging.

Blue Whiting

The blue whiting, Micromesistiuspoutassou, (Fig. 14) is also a gadoidfish and can be recognized by its bluishcolor, long slender shape, and lack ofbarbel.

Blue whiting is usually found in wa­ters > 100 fathoms (> 183 m) deep onand beyond the edge of the continentalshelf. It is distributed from the Mediter­ranean to the north of Norway and Ice­land, and some are found in the Ba­rent's Sea and off Spitzbergen. Largeamounts have been found west of Brit­ain and in the Norwegian Sea (Anon­ymous, 1976).

Results of fishery research work car­ried out so far indicate that a stock of atleast several million tons of blue whit­ing exists in the northeast Atlantic westof the British Isles. At present, it ap­pears most likely that this species couldsustain an annual yield of over1,000,000 t which could be used in themanufacture of a wide range of fisheryproducts (Anonymous, 1976). Consid­erable research is being carried out byGreat Britain to market this fish in theform of fish blocks.

Other Species

Burbot

A freshwater relative of the Atlanticcod, the burbot, Lota Iota, is found inthe Great Lakes and in smaller lakesand some rivers of the north centralstates and Canada. Usually, it remainsin the deeper part of the water. It is along and rather slender fish with three

whisker-like barbels. It looks more likecusk than a cod. The average size ofburbot is about 15 inches (38.1 cm)long and 1pound (454 g) in weight. Theburbot also occurs in the northern partof Eurasia.

The flesh of the burbot resembles thatof the cod and haddock. Salt burbot isvery much like salt codfish and is verypopular in Europe for its white and deli­cate flesh. Large quantities of burbotare marketed as pet food.

TomcodThere are two tomcods: 1) The Atlan­

tic tomcod, Microgadus tomcod, and 2)the Pacific tomcod, Microgadus prox­imus. The Atlantic tomcod, also calledfrost fish, looks exactly like Atlanticcod but is much smaller and has blotch­ier color patterns. The maximum lengthis about 14 inches (35.6 cm) with most9-12 inches (22.9-30.5 cm) long.

The Pacific tomcod is found fromCalifornia to Alaska. Both species livein estuaries or shallow water and areoften caught by recreational fishermen.Tomcod has limited commercial use ashuman food because it is not abundantenough.

European Cods

Some members of the cod familywhich are landed in England and north­ern Europe are the big or whiting pout,Trisopterus luscus; the European whit­ing, Merlangius merlangus merlangus;the poor cod, Trisopterus minutusminutus; the Norway pout, Trisopterusesmarkii; and the fork beard, Phycisblennoides. The European ling, Molvamolva, is dried as stockfish in Iceland.This species is not common to the At­lantic waters of North America (Jensen,1972).

Fourbeard Rockling

The fourbeard rockling, En­chelyopus cimbrius, occurs on bothsides of the North Atlantic. Color ofback is brown or dark olive with a whitebelly dotted with brown. On the NorthAmerican side, it is found from New­foundland to New York in coastal wa­ters and as far south as North Carolinaon the continental shelf (Bigelow andWelsh, 1925). It is small, reaching alength of about I foot (30.5 cm). The

Marine Fisheries Review

fourbeard rockling is a bottom dwellingfish found in depths of water from2,000 to over 4,000 feet (610 to over1,220 m). Its principal foods are smallfishes and crustaceans. It has noeconomic value.

Cusk

Cusk, Brosme brosme, also occurson both sides of the Atlantic (Leim andScott, 1966). On the North Americanside, it is found from Newfoundland toCape Cod and may go as far south asNew Jersey. It is found in waters from10 to 300 fathoms (18.3 to 549 m). Itprefers cool water and a rough, rocky,gravelly, or pebbly bottom. Its colorvaries according to the bottom wherethe fish live: The back ranges fromsooty to dull reddish brown withgrayish lower sides; white dorsal, anal,and caudal fins have black marginsedged narrowly with white. It is easilyseparated from other relati ves by thefact that it has but one dorsal fin. Itsaverage length is Ilh-2V2 feet (0.5-0.8m), and the weight varies from 5 to 30pounds (2.2 to 13.6 kg). Spawningtakes place in spring and summer. Cuskfeed on crustaceans and shellfish. Thecusk is a good food fish marketedlargely as fresh and frozen fillets in thecommercial fisheries north of CapeCod. Unlike most of the other bottomfishes, it does not school but is solitary.It is usually caught incidental to codfishing. The European cusk (torsk) isfound on the European coast, on thenorth coasts of the British Isles, Den­mark, the northern part of the NorthSea, and Kattegat to Iceland, and theMurman Coast (Leim and Scott, 1966).

False Cods

Because of the successful marketingof cod, a number of "false cods" haveappeared (Jensen, 1972). These "falsecods" include the sablefish, also calledblackcod, Anoplopoma fimbria,(southern California to northwesternAlaska); the longs pine channel(thornyhead) cod, Sebastolobus al­tivelis, (from Baja California, to theAleutian Islands); the chilipepper,Sebastes goodei, (Baja California, toCape Scott); the lingcod or cultus cod,Ophiodon elongatus, (southern Cali-

November 1979

fornia to northwestern Alaska); and thebull or blue cod, Scorpaenichthysmarmoratus, actually a sculpin whosecommon name is cabezon (off thePacific coast).

Most of these species belong to thescorpion fish family, Scorpaenidae.The Pacific coast's sablefish has a highreputation as a smoked product. Ling­cod is a member of the Hexagrammidaefamily, a group known as greenlings. Itis highly esteemed as a food fish on thePacific coast. It is marketed as dressed,fillets, and steaks. A large portion goesinto the "fish and chips" trade.

Utilizing the Cod

Cod as Food

As a food fish, cod is very adaptable.Its flesh is nutritious without beingfatty. It adapts to almost all forms offish cookery with its meat being whiteand delicately flavored.

A yield of 41-45 percent is typical formachine filleted skinless cod with anaverage of 43 percent. On an average,the chemical composition of the Atlan­tic cod is as follows: Fat, 0.3 percent;protein, 17.9 percent; ash, 1.1 percent;and moisture, 81.1 percent (Sidwell,1974).

The flesh of the cod family is rathercoarse grained and low in fat becausethe fish store most of their fat in the liverrather than in the flesh.

As the cods usually have their gillsremoved from April to November andare eviscerated at sea, the best signs offreshness in eviscerated cod arefirmness of flesh, odor in the belly cav­ity, and the condition of the eyes. If theeyes are cloudy and sunken, spoilagemay be present. The appearance andodor of the slime is an indicator offreshness.

One factor that has led to the in­creased consumption of cod in recentyears has been the rise of "fish andchips" type restaurant chains. Onesuch restaurant chains' consumption ofcod blocks is now running in excess of9,000 t (20 million pounds). Other fastfood service chains have elected to usecod rather than alternative species intheir fish sandwiches. Medium priced,family style restaurants are also large

users of cod fillets and breaded por­tions.

Harvesting the Cod

Today, about 85 percent of the Gulfof Maine Atlantic cod catch is made byotter trawls, only about 10 percent inlonglines, about 1 percent in gill nets,and less than 1 percent in pound nets orhandlines (Jensen, 1972). Others arecaught by traps, jiggers, and Danishseines. In 1976, 55,800,000 pounds(25,300 t) of Atlantic cod were landedin the United States (Robinson, 1977).The 5-year average (1971-75) was53,200,000 pounds (24,100 t).

Normal cruising duration for trawl­ers is 7-10 days when trawling fQr codand other groundfish. Fishing opera­tions are from 4 to 7 days in duration,the average being 5 days. Fishing oper­ations are carried out "round-the­clock" by alternating deck crews.

Handling the Catch

Aboard the vessel, the fish are re­moved from the water as soon as possi­ble after catching. Trawl-caught fishare washed to remove sand, mud, ordebris. They are always eviscerated toeliminate bacteria and enzymes fromthe intestines. Often the gills are re­moved between April and November,and the fish are washed again in cleanwater. The cod are then stored inenough crushed ice to keep them asclose to 32°F (O°C) as possible. Correcticing requires a great deal of care andexperience. Sufficient ice should beplaced on the floor of each pen. Ampleice should be placed at the sides of thevessel and adjacent to the wing boardsof each pen.

Boxing is being adopted aboardmany of the progressive vessels be­cause it can be the most satisfactorymethod of stowing fish in the hold. Itoffers the additional advantage that thefish can be landed in the same boxes anddistributed without further rehandling.Boxed fish are not often crushed orbruised as shelved or bulked fish. Thecontents and the date of catch may berecorded on each box. The boxes maybe either wooden, light plastic, or metalalloy. They are designed so that a stackof them is stable. Drainage is designed

33

so that the melted ice water runs to thecomers of the bottom so the box will notdrain into the box below. They makeunloading the fish much simpler.

Selling the Catch

The fisherman's catch may be sold ina variety of ways. Fish may be sold atauction or directly to a shore plant at theprevailing auction prices. In somecases, the boats may be working undercontract or be owned by a shore plant.In the Boston area, the catch is sold tothe processors through the New En­gland Fish Exchange. At the Exchange,processors are offered, through publicauction, the opportunity to bid for eachvessel's catch. State and Federal fishinspectors may examine the catch forcondition and quality.

Once the catch has been sold, un­loading of the fish is begun. The fish arehoisted out of the hold of the vessel in100-pound (45.5-kg) capacity canvasbaskets which are emptied into wooden"weigh" boxes mounted on scales.After weighing, the fish are transferredinto carts, boxes, or barrels and trans­ported to the fish plants for processing.If the fish are not processed immediate­ly, they are reiced or held in chill roomsat as close to 32°F (O°C) as possible.

The usual market classifications inthe New England Fish Exchange are:Scrod, 1.5-2.5 pounds (0.7-1.1 kg);market, 2.5-10 pounds (1.1-4.5 kg);large, 10-25 pounds (4.5-11.3 kg); andextra large, over 25 pounds (> 11.3kg).

Today the usual market forms of codare dressed fish, steaks, skin-on fillets,and skinless fi llets. Dressed andsteaked cod are sold freshly iced, andthe fillets are sold both fresh and frozen.The steps involved in preparing filletsconsist of: 1) Washing the fish, 2) fillet­ing the fish, 3) skinning the fillets(where applicable), and 4) washing orbrining the fillets.

Processing

In processing, the fish are firstwashed with cold potable water orchlorinated seawater to remove slime,blood, and ice. The washed fish arethen carried by conveyor belt to the

34

filleting area where filleting operationsare done by hand or, in the more mod­em plants, by automatic machinery.After filleting, the fillets mayor maynot be skinned. If the fillets are skinned,the skin is removed either by hand or byautomatic machinery. The fillets arethen conveyed on a moving belt to atank containing brine or water for wash­ing the fillets. Brine, when used, isnormally 10-15 degrees salometer.After brining or dipping in water, thefillets are drained on an inclined con­veyor belt and conveyed to the packingtables where they are inspected forblemishes.

Fillets

Fillets used in retail trade are placedin either 12-ounce (0.3-kg) or I-pound(0.45-kg) telescoping cartons which inturn are overwrapped with heat-seal­able, moisture-vapor-proof material.Fillets used for the institutional tradeare wrapped in approximately I-pound(454-g) packages using a transparentinnerwrap of cellophane or its equiva­lent and which are, in turn, packed into5- or 10-pound (2.3- or 4.5-kg) waxcardboard master cartons. Slack fill isavoided during packaging, since thepresence of voids will contribute to aloss of quality during frozen storage.

The packaged fillets are blast frozenin air or are plate frozen; the lattermethod is more common and results ina better looking pac:':aged product. Inthe plate freezer, the filled packages areplaced in metal trays which, in tum, areinserted between two refrigeratedplates. When the freezer is loaded, therefrigerated plates are hydraulicallylowered so that contact is maintainedbetween the top and bottom of thepackages and the refrigerated platesduring the freezing period. Suitablespacers are used between plates tomaintain sufficient space betweencartons to prevent their being crushedduring freezing. After freezing, thepackages of frozen fillets are packed inmaster cardboard cartons and placed infrozen storage. To prevent rapid loss inquality during storage, a temperature ofless than O°F (-18°C) should be main­tained until the fillets, as well as allother fishery products, are delivered to

the consumer at the retail market.Freezer storage temperatures above O°F(-18°C) result in a rapid loss in qualitydue to toughening and rancidity.

Fish Fillet Blocks

A large portion of the foreign codcaught is imported for the production offish sticks and portions. Fish filletblocks are prepared by placing theboneless and usually skinless fillets in afiberboard container either parallel orperpendicular to the long axis of thecontainer. The thick part of the fillet isplaced adjacent to the edge of the con­tainer, and the thin portion is placed inthe center. The depression is filled upwith fillets until the desired weight isobtained. The most popular weights offish blocks are 13.5 pounds (6.1 kg),16.5 pounds (7.5 kg), and 18.5 pounds(8.4 kg). For freezing, the blocks areput into a tray and placed into a multi­plate compression freezer with spacersslightly smaller in depth. This causes aslight compression which smooths outthe surface and fuses the fillets into asingle block.

The fish blocks are further processedby cutting with a band saw or gang saw(series of circular saw blades on a singleaxis) or by shearing with a guillotine­type machine into fish sticks or largerfish portions in sizes between 1.5 and 5ounces (43 and 142.0 g). These sticksor portions are covered with a liquidbatter and then dusted with breadcrumbs. Recently, a new processingtechnique using a tempura-type batteras the sole covering has been quite suc­cessful. Tempura is a viscous batterwhich is applied over a flour or drybatter base and then fried. The batterand breading ingredients are usuallysupplied by specialty manufacturers ofthese items. Following battering andbreading, the sticks and portions maybe heated in oil at about 375°F(190.6°C) for 30 seconds or less. Fol­lowing this operation, the sticks andportions are coole'd and may be eitherindividually frozen and packaged orpackaged and frozen in a plate freezer.As is done with the frozen cod fillets, astorage temperature of at least O°F(-18°C) should be maintained to retainthe quality of the sticks and portions.

Marine Fisheries Review

Figure IS.-Fry of Atlantic cod.

Salted Cod

Although the amount of salted fishproduced in the United States is verysmall, imported salt-dried cod is stillused as such or as fish cakes. Salt-driedfish is normally prepared by heading theeviscerated fish and splitting it open tothe tail. After removing the backbone,the fish are washed and the black liningis removed. The washed fish are saltedflesh side up either in a large barrel orpiled on a solid floor (kench). The fishare laid in piles with layers of salt inbetween until the top layer of fish isreached, which is placed skin side up.

Sal t content of cod varies from 4 per­cent for a very lightly salted productwith a curing time of 2 days to 20 per­cent for a heavily salted product curedfor about 21 days. The heavily curedsalt cod is usually dried to about 40percent moisture content. At low tem­peratures of 32°_40°F (OO-4.41°C) nobacterial spoilage in hard cures may benoticed for years. With lighter cures,storage at chill temperatures is essen­tial.

The traditional method of drying wasto expose the fish to sun and wind,usually on frames known as flakes. Asthis method is slow, artificial dryingbecame popular. The most suitable airtemperature is 75°F (23.9°C) with arange of 60°_80°F (l5.6°-26.7°C). Rel­ative humidity of the dryers should be50-55 percent as dried salt fish absorbswater at relative humidites above 76percent. Salt cod, after drying, is oftenskinned and boned by hand and pack­aged in small wooden boxes or plasticfilms in I-pound portions.

A new rapid salt-curing techniquehas been developed at the GloucesterLaboratory (Northeast FisheriesCenter, NMFS) which produces a salt­cured fish in less than 8 hours (Mendel­sohn, 1974). It involves grinding thefish to increase the surface area exposedfor salting. After grinding, the fish iscovered immediately with brine so ex­posure to oxygen is almost obviated.Additional salt to maintajn saturation isused so salting takes place throughoutthe ground fish. Drying is aided by thesmall particle size of the ground fishwhich also simplifies the reconstitutionof the dried product.

November 1979

Fish Cakes

Fish cakes are prepared by soakingsalt cod in cold water. The water isdrained off, and the fish boiled withfresh water with about double theweight of potatoes. Beaten eggs, butteror margarine, diced onions, and pepperare added, and the mixture is formedinto cakes, rolled in bread crumbs, anddeep-fat fried until light brown. Thefish cakes are cooled on trays, thenpackaged in cold-waxed cartons usingwaxed paper separators. The cartonsare closed, then overwrapped and fro­zen in a plate or blast freezer. Afterfreezing, the cartons are packed in cor­rugated containers for storage or ship­ment.

Smoked Cod

For smoking, cod fillets are normallyskinned and brined in a 70-80 percen'brine for 4-10 minutes depending uponsize. The brined fish are allowed tostand and drip before smoking. Thesmoking time varies frorr. 2 to S hoursaccording to size. The temperature ofthe kilns is usually controlled at 80°F(2rC).

Codworm

On the Atlantic coast, the nematodePorracaecum decipiens, called "cod­worm," is often found in cod, but itmay also be found in hake, flounders,and ocean perch. Generally, the infesta­tion incidence of codworm is high ininshore areas sometimes with over 50percent of the cod infested. The numberof parasites per fish is much larger ininshore fish than in fish caughtoffshore. Codworm larvae range from\4 inch to 31/2 inches (6.35 to 88.9 mm)in length and are white to reddish brownin color. The larvae are usually found

burrowed into the muscle of the fillet.Candling-placing the fish fillet on aglass plate with a strong light below­is the best method of detecting the cod­worms. The parasite can be removedwith tweezers or by cutting it out with aknife.

The life cycle of the codworm is asfollows: Adult worms lay eggs in theintestines of the harbor seal, Phoca vi­tulina, or gray seal, Halichoerus gry­phus, which then pass through the sealfeces into the ocean. The eggs hatch,and the larvae are eaten by an inverte­brate such as a shrimp which is theneaten by fish. In the larval form, thecodworm cannot reproduce. When fishinfested with these larvae are eaten by aseal, the worms mature and completethe cycle. These parasites are not harm­ful to humans but are considered aes­thetically objectionable.

Conservation

As early as the 16th century, Englishfishermen complained about mesh sizesin the rough trawl nets used by otherfishermen. In 1558, Queen Elizabeth Ipublished a Royal Decree giving aminimum limit of 2V2 inches (6.4 cm)mesh size. It was recognized early thattrawl nets, while quite efficient, tendedto catch many unmarketable, small­sized fish which represented a waste.

Early work of the U.S. Fish Com­mission was concentrated on increasingthe number of cod in the sea by artificialpropagation. Cod were first raised atGloucester, Mass., during the winter of1878-79. Additional hatcheries werebuilt in Boothbay Harbor, Maine, andWoods Hole, Mass. At the Gloucesterstation, 217 million cod eggs were fer­tilized. The fertilized eggs were movedto hatching trays for further develop­ment. The newly hatched fry (Fig. 15)

35

were taken from the traps and releasedin the harbor.

The Woods Hole hatchery continuedits work until World War II, but thehatcheries at Gloucester and BoothbayHarbor ended earlier.

Following the conclusion of manytagging experiments in Europe andNorth America and a trawling study ofGeorges Bank by David Belding, it wasfound that 14.3 percent of the codcaught in the otter trawl had to be dis­carded because of their small size (Jen­sen, 1972). Further tests by the U.S.Bureau of Fisheries found that 40 per­cent by weight of immature cod werecaught in the otter trawl.

After widespread research by fisheryscientists, a regulation was im­plemented banning the use of trawl netswith a mesh size smaller than 4Vz inchesin the cod and haddock fisheries. Thismesh regulation was adopted by the In­ternational Commission for the North­west Atlantic Fisheries composed ofCanada and II European countries.

The establishment of 200-mile limitsand their control by systems of quotaswill result in the conservation of the keyspecies of fish in the North Atlantic andPacific fisheries, i.e., such species ascod, haddock, whiting, and pollock.

Acknowledgments

The author gratefully acknowledgesJohn D. Kaylor, Gloucester Labora­tory, who reviewed the manuscript, andDan Cohen, National SystematicsLaboratory, who provided copies oforiginal drawings from the Museumfiles.

Literature CitedAnonymous. 1976. Blue whiting is no easy sub­

stitute in Britain for the cod. Fish. News Int.15(5):40-42.

Bailey, R. M., J. E. Fitch, E. S. Herald, E. A.Lachner, C. C. Lindsey, e. R. Robins, and W.B. Scott. 1970. A list of common and scientificnames of fishes from the United States andCanada. 3d ed. Am. Fish. Soc. Spec. Publ. 6,150 p.

Bigelow, H. B., and W. W. Welsh. 1925. Fishesof the Gulf of Maine. U.S. Bur. Fish., Bull.40:1-567.

36

Capalbo, S. M., and R. K. Kinoshita. 1977. Foodfish market review and outlook. U.S. Dep.Commer., NOAA, Natl. Mar. Fish. Serv.,Curro Econ. Anal. F-26, 48 p.

Food and Agriculture Organization of the UnitedNations. 1976. Catches and landings. 1975.FAO Yearb. Fish. Stat. 40,417 p.

Grinols, R. B., and M. F. Tillman. 1970. Pacifichake-importance of the worldwide hake,MerLuccius, resource. In Pacific hake, U.S.Dep. Commer., Natl. Mar. Fish. Serv., Circ.332, p. 1-21.

Hart, J. L. 1973. Pacific fishe, of Canada. Fish.Res. Board Can., Bull. 180,740 p.

Jensen, A. C. 1972. The cod. Thomas Y. CrowellCo., N.Y., 182 p.

Jordan, D. S., and B. W. Evermann. 1902.American food and game fishes. Doubleday,Page Co., N.Y., 573 p.

Leim, A. H., and W. B. Scott. 1966. Fishes ofthe Atlantic coast of Canada. Fish. Res. BoardCan., Bull. 155,485 p.

Mendelsohn, J. M. 1974. Rapid techniques forsalt-curing fish: A review. 1. Food Sci.39: 125-127.

Robinson, L. A. (editor). 1977. Fisheries of theUnited States, 1976. U.S. Dep. Commer.,NOAA, Natl. Mar. Fish. Serv., Curro Fish.Stat. 7200, 96 p.

Sidwell, V. D., P. R. Foncannon, N. S. Moore,and J. C. Bonnet. 1974. Composition of theedible portion of raw (fresh or frozen) crusta­ceans, finfish, and mollusks. I. Protein, fat,moisture, ash, carbohydrate, energy value, andcholesterol. Mar. Fish. Rev. 36(3):21-35.

Selected ReferencesAckerman, E.A. 1941. New England's fishing

industry. Univ_ Chicago Press, Chicago, 303p.

Babson, J. J. 1860. History of the town ofGloucester, Cape Ann, including the town ofRockport. Proctor Bros .. Gloucester, Mass.,610 p.

Baird, S. F. 1873. Description of apparatus usedin capturing fish on the sea-coast and lakes ofthe United States. U.S. Comm. Fish Fish., partI, 1871 and 1872:253-274.

____ . 1874. Conclusions as to decrease ofcod-fisheries on the New England coast. U.S.Comm. Fish Fish., part 2, Rep. Comm. 1872and 1873:xi-xiv.

Brice, J. J. 1898. A manual of fish-culture. Rep.U.S. Comm. Fish. for 1897, 23:1-340.

Butler, e., J. A. Dassow, e. J. Carlson, J.Carver, and M. Heerdt. 1956. Refrigeration offish-Part 2, Handling fresh fish. U.S. FishWildl. Serv., Fish. Leafl. 428, 84 p.

Carson, R. L. 1943. Food from the sea, fish andshellfish of New England. U.S. Fish Wildl.Serv., Conserv. Bull. 33,74 p.

Dassow, J. A., S. R. Pottinger, and J. Holston.1956. Preparation, freezing, and cold storageof fish, shellfish, and precooked fishery prod­ucts. U.S. Fish Wildl. Serv., Fish. Leafl. 430,124 p.

Earll, R. E. 1880. A report on the history andpresent condition of the shore cod-fisheries ofCape Ann, Mass., together with notes on thenatural history and artificial propagation of thespecies. U.S. Comm. Fish Fish., part 6, Rep.Comm. 1878:685-740.

Edwards, R. L., and L. Lawday. 1960. Speciescomposition of industrial trawl fish landings inNew England, 1958. U.S. Fish Wildl. Serv.,Spec. Sci. Rep. Fish. 346, 20 p.

____ , and F. E. Lux. 1958. New En­gland's industrial fishery. Commer. Fish. Rev.20(5): 1-6.

Fritz, R. L. 1960. A review of the Atlantic coastwhiting fishery. Commer. Fish. Rev.22(11): I-II.

Haberland, H. 1946. Gloucester-three cen­turies a fishing port. U.S. Fish Wildl. Serv.,Fish. Leafl. J92, 5 p.

Herrington, W.e. 1935. Modifications in gear tocurtail the destruction of undersized fish inotter trawling. [U.S.] Bur. Fish., Invest. Rep.24, 48 p.

____ . 1936. Decline in haddock abun­dance on Georges Bank and a practical reme·dy. [U.S.] Bur. Fish., Fish. Circ. 23, 22 p.

Jensen, A. e. 1967. A brief history of the NewEngland offshore fisheries. U.S. Fish Wildl.Serv., Fish. Leafl. 594, 14 p.

____ , and R. K. Brigham. 1963. Theline-trawl fishery for cod and haddock atChatham, Massachusetts. Commer. Fish. Rev.25(6):14-J9.

____ , and H. E. Murray. 1965. The U.S.cod fisher)' in the Northwest Atlantic. Com­mer. Fish. Rev. 27(7):1-11.

Sabine, L. 1853. Report on the principal fisheriesof the American seas: Prepared for the Trea­sury Department of the United States. RobertArmstrong, Printer, Wash., D.e., 317 p.

Slavin, J. W., and M. Heerdt. 1956. Refrigera­tion of fish-Part 5, Distribution and marketingof frozen fishery products. U.S. Fish Wildl.Serv., Fish. Leafl. 431, 78 p.

Stansby, M. E., S. R. Pottinger, and D. T.Miyauchi. 1956. Refrigeration of fish-Part 3,Factors to be considered in the freezing andcold storage of fishery products. U.S. FishWildl. Serv., Fish. Leafl. 429, 65 p.

Sundstrom, G. T. 1957. Commercial fishing ves­sels and gear. U.S. Fish Wildl. Serv., Circ. 48,48 p.

Tressler, D. K., and e. F. Evers. 1957. Thefreezing preservation of foods. 3d ed. 2 vols.Avi Publ. Co., Inc., Westport, Conn.

____ , and J. M. Lemon. 1951. Marineproducts of commerce. 2d ed. Reinhold Publ.Corp., N.Y., 782 p.

Wheeler, e. L. 1955. The ocean fishery, Mas­sachusetts oldest industry. Mass. Dep. Nat.Resour., Div. Mar. Fish., Boston, 27 p.

White, D. J. 1954. The New England fishingindustry. Harv. Univ. Press, Camb., 205 p.

Wise, J. P. 1963. Bibliography on the biology ofthe cod Gadus morhua and related species.U.S. Fish Wildl. Serv., Fish. Bull. 62:483­538.

Marine Fisheries Review