The Seafood Industry (Species, Products, Processing, and Safety) || Freshwater Fish

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14 Freshwater Fish

Denise Skonberg and Thomas E. Rippen

Freshwater fish make up less than 5% of the com-mercial harvest of wild fishery stocks in the UnitedStates, yet several species find traditional markets,primarily in the Midwest, where they are highlyprized. Consequently, seafood firms wishing toserve inland customers should evaluate local con-sumption patterns prior to introducing unfamiliarproducts.

Most freshwater fishing in the United Statesremains centered in the Great Lakes area, despitea dramatic decline in food species in recent years.Great Lakes is the collective name for lakes Supe-rior, Michigan, Huron, Erie, and Ontario, which alldrain to the Atlantic via the St. Lawrence River.Combined with the large lakes of central and west-ern Canada, they contain approximately 40% of theworld’s fresh surface water. This chapter empha-sizes these traditional North American fisherieswith occasional reference to less important lakesand river systems. The bias toward North Americanfisheries should not be misinterpreted as suggest-ing that other freshwater systems are insignificant.Subsistence fishing on Lake Titicaca and the greaterAmazon drainage of South America and on thelarge rivers of China, for example, has had a majoreconomic and historic impact on the people of thoseregions. Likewise, important targeted fisheries exist

for pike and whitefish in scattered locations inEurope and Asia, as they do for Nile perch in LakeVictoria, Africa. The US experience is highlighted asa study of commercial freshwater fishing, reflectingdynamic social values and market demand.

This chapter is also confined to selected wildfreshwater species. Most freshwater trout, catfish,and crayfish are produced under controlled condi-tions, which will be discussed in Chapter 24. Somespecies or populations of sturgeon, salmon, eels,shad, and other fish inhabit freshwaters during aportion of their life to spawn or feed, but they aregenerally considered marine species and as suchare discussed in detail elsewhere.

During storage and preparation, fish perfor-mance varies according to their physiological andbiochemical makeup, which in turn is dictated bytheir environment. This chapter addresses factorsthat distinguish freshwater species from their salt-water relatives. We also discuss processing meth-ods, products, and distribution channels.

Current status

The overall effect of the activities of humans andnonnative fish has been a shift in market products

The Seafood Industry: Species, Products, Processing, and Safety, Second Edition. Edited by Linda Ankenman Granata,George J. Flick, Jr. and Roy E. Martin.C© 2012 Blackwell Publishing Ltd. Published 2012 by Blackwell Publishing Ltd.



162 The Seafood Industry: Species, Products, Processing, and Safety

from large, high valued species to small fish of lowvalue. The successful stocking of salmonids, includ-ing coho and chinook salmon, may help controlpopulations of nuisance fish but has little directimpact on regional fishing fleets. Most borderingstates are committed to recreational rather thancommercial fisheries. Species of trout, salmon, wall-eye, blue pike, smallmouth bass, and several othersare generally not permitted or are limited in the UScommercial catch. Access to the commercial fisheryis controlled by gear and license restrictions. Wis-consin issues about 200 licenses per year, Michiganand Ohio about 100 each, with another 100 issuedby the combined states of Minnesota, Pennsylvania,Indiana, and Illinois. These states plus New Yorkcontain 7527 km (4678 mi) of shoreline, equalingOntario’s waterfront.

By contrast, Canada regulates the commercialharvest of most traditional and introduced speciesincluding lake trout, walleye, northern pike, stur-geon, splake, and Pacific salmon. Ontario issuesabout 1000 licenses each year written for a widevariety of gear types including over 11,887 km(13 million yd) of gillnet, a net which has beenseverely restricted by most states in the US. TheGreat Lakes commercial fishery comprise primar-ily of whitefish, yellow perch, rainbow smelt, andchubs. Lake whitefish represent the highest valuefish landed in US waters, with total landings ofmore than 9.5 million lb worth $8.1 million in 2008.However, yellow perch, walleye, rainbow smelt,and chubs are all higher value species on a perpound basis, with average landed values of $2.25,$1.93, $1.92, and $1.21/lb, respectively, in 2008. InCanada, yellow perch and walleye account for thehigh value of the Ontario harvest, with 2006 landedvalues of Can$17.6 million and Can$12 million,respectively.

Most US fishing occurs in the western Great Lakeswith only a minor fishery in lakes Erie and Ontario(Table 14.1). Canadian fleets account for nearly allthe increased catch in the eastern lakes. Sales ofsmelt, yellow perch, and walleye have elevated thevalue of landings from Canadian waters of LakeErie from $6 million in the middle 1970s to $59 mil-lion in 1991. Currently, the Lake Erie fishery makesup about two-thirds of the Canadian Great Lakescommercial fishery harvest.

The discovery of DDT, polychlorinated biphenyl(PCBs), dieldrin, mercury, and other contaminantsin Great Lakes fish hampered the fishing industry as

Table 14.1 US landings of selected commercially harvestedfreshwater fish in 2008.

Species Weight (lb) Value ($)

Blue catfish 3,285,437 1,525,128Burbot 12,286 5434Chubs 733,966 888,842Common carp 1,154,344 204,008Lake Trout 666,548 240,451Rainbow Smelt 446,984 858,362Tilapia 62,576 42,894Walleye 48,252 93,583White bass 426,303 320,098White mullet 318,864 185,817White perch 1,834,249 1,277,983Whitefish 9,550,007 8,118,865Yellow perch 2,191,293 4,934,008

certain species were banned. Several contaminantsmonitored by state and federal agencies have gen-erally fallen below tolerance levels, permitting thesale of some formerly banned products. Unfortu-nately, recent research has renewed concerns aboutcontaminants and has led to heightened regulatoryactivity.

Other fisheries

Traditional fisheries exist in the Mississippi Riverand its tributaries, the inland waters of Florida andcertain US lakes, notably the Red Lakes and Bound-ary Lakes of Minnesota, and the large Canadianlakes of the prairie provinces and Northwest Ter-ritories. Historically, the Mississippi River systemproduced landings rivaling the Great Lakes, butnow much of the catch has a lower market value.Catfish, carp, buffalofish, and sheepshead still pre-dominate.

The Boundary Lakes (Lake of the Woods andRainy Lake) have annually produced large yields ofwalleye, northern pike, and lake herring, althoughMinnesota has sharply curtailed commercial fish-ing in these waters with significant reductions onthe Canadian side as well. An Indian gillnet fisheryon the Red Lakes has historically been highly pro-ductive, producing up to 318,000 kg (700,000 lb) ofwalleye a year, 454,000 kg (1 million lb) of yellowperch, 36,400 kg (80,000 lb) of whitefish, 22,700 kg(50,000 lb) of northern pike, and 454,000 kg (1 mil-lion lb) of suckers and sheepshead. A moratorium



Freshwater Fish 163

was imposed in 1997 on harvesting walleye in thisfishery following a crash in the population. A majorconservation program resulted in strong recoveryof the stock and harvesting resumed in 2006.

Canada’s inland fisheries include 11 comme-rcially important lakes in Manitoba, Saskatchewan,Alberta, and the Northwest Territories. Walleye,whitefish, northern pike, lake trout, sauger, lakeherring, and arctic char are the most valuablespecies. They are harvested primarily with gillnetsfished in either open water or under the ice andwith poundnets, trapnets , and seines.

Markets/processing

The freshwater industry remains based on tradi-tional products and markets. Most fish are whole-saled fresh, usually whole but also dressed, filleted,or chunked. Typically, family-owned or coopera-tive fishing operations on the Great Lakes includea simple shoreline facility for cutting, icing, boxing,and storing the catch. The fish are sold locally orshipped (usually contracted with trucking firms) towholesale distributors in major cities, most notablyChicago.

Many of these small businesses operate a smoke-house for hot-smoking (kippering) drawn, dressed,or chunked fish. Chubs, lake whitefish, lake her-ring, and imported whiting are the species com-monly selected for smoking. Smoked products aremostly consumed locally although a few large vol-ume processors and distributors ship finished prod-ucts to distant metropolitan centers, including NewYork and Miami. Some of the most modern process-ing and distribution plants are located in Canada.They are generally very competitive with US firms,offering buyers attractive prices and relatively sta-ble supplies, although seasonal gluts contribute toperiodically suppressed prices.

The historically important salt-cured lake her-ring trade has virtually disappeared. Years ofpoor catches and changing consumer attitudesare probably responsible. Efforts by processorsto diversify their product lines have met withencouraging but generally modest results. Somewhitefish roe is screened, washed, and brined forfurther processing into caviar; certain underuti-lized species, including suckers, lake herring, andround whitefish, are mechanically deboned to makemince.

Freshwater fish are the primary ingredient inprocessed products destined for the Jewish trade,notably gefilte fish, which is made by cooking sea-soned fish dumplings in a vegetable/fish stock.Important species include whitefish, carp, andwalleye.

Composition and quality

Shelf life

In general, spoilage patterns are similar for fresh-water and saltwater fish. Bacterial composition maybe somewhat different during certain stages ofdecomposition but proteolytic (protein-consuming)microorganisms lend familiar putrefactive flavorsand odors to both groups. As with saltwater fish,enzymatic activity varies with species and season.

Despite similarities, freshwater products, onaverage, maintain quality longer than do theirmarine counterparts. This fact is generally attri-buted to the presence of light-weight compoundsknown as osmoregulators in saltwater fish.Although important for balancing flesh “salt” con-tent with the marine environment, bacteria read-ily break down these compounds as a food source.Deterioration of osmoregulators is associated withammoniacal odors, bitter flavors, and undesirabletextural changes during frozen storage of suscepti-ble seafoods.

Freshwater fish must deal with a harsh envi-ronment relatively free of electrolytes. As a result,water invades their tissues under osmotic pressureand must be excreted as copious dilute urine. Theydo not drink. Chemical osmoregulators would becounterproductive. Consequently, related shelf-lifeproblems are notably absent.

Red versus white muscle

As with saltwater species, freshwater fish havemuscle ranging from white to well-defined regionsof white meat and dark meat to mostly dark meat.However, few species of freshwater fish containflesh as highly pigmented as some migratory salt-water fish. The red blood pigment, hemoglobin,and muscle pigment, myoglobin, bind oxygen fortransport and storage. These pigments can release




Table 14.2 Nutrients in selected freshwater fish species (per 100 g wet weight)

Species Protein (g) Fat (g) Water (g) Mineral (g) Kcal Omega-3 (mg)

Burbot 19.3 0.8 79.3 1.2 90 192Carp 17.8 5.6 76.3 1.5 127 704Channel catfish 16.4 2.8 80.4 1.0 95 535Perch 19.4 0.9 79.1 1.2 91 283Pike 19.3 0.7 78.9 1.2 88 142Rainbow smelt 17.6 2.4 78.8 1.4 97 760Walleye 19.1 1.2 79.3 1.2 93 363Sunfish 19.4 0.7 79.5 1.1 89 152Whitefish 19.1 5.9 72.7 1.1 134 1604

oxygen for desirable chemical reactions in the tis-sues while making it unavailable for detrimentalreactions.

Saltwater species that require great quantities ofenergy for swimming rely primarily on metabolismof tissue oils, an oxygen-consuming process. Conse-quently, most free swimming species are both dark-fleshed and oily. Freshwater species are less likelyto expend large quantities of energy for movement.Even species that do, such as migratory freshwa-ter trout, function with little red muscle probablybecause they frequent well-oxygenated water. Afew freshwater fish that are highly pigmented mayhave adapted to low oxygen environments. Carpand bullhead catfish are examples.

Nutrient composition

Like their saltwater counterparts, freshwater fishare an excellent source of high-quality protein, withprotein contents typically ranging from 16 to 20g/100 g wet fillet. Fat content of fillet is highly vari-able, depending on species, geographical location,and season of harvest. Fish harvested in late sum-mer have higher fat contents and correspondinglyhigher energy values (kilocalories) than fish caughtin late winter. The contents of omega-3 fatty acids,including linolenic (18:3), EPA (20:5), DPA (22:5),and DHA (22:6) are also highly variable withinfreshwater fish species, and are generally somewhatlower than the omega-3 fatty acid contents of salt-water fish. However, wild caught channel catfish,rainbow smelt, and carp all contain more than 500mg omega-3 fatty acids per 100 g (3.5 oz) serving,and omega-3 fatty acid contents of lake trout andwhitefish are considerably higher. Typically, the fat

in cold-water fish has a higher percentage of omega-3 fatty acids than in warm-water fish. Cholesterolcontents for freshwater fish are low, ranging fromapproximately 40–90 mg/100 g. The nutrient val-ues for selected freshwater fish species listed inTable 14.2 were obtained from the USDA NationalNutrient Database and represent values averagedfrom multiple sources of data.

Consumer preference

Marketing strategies often emphasize oil content,color, texture, and flavor intensity as a basis forclassification of fish species. Lake trout, lake white-fish, and similar freshwater species may prove help-ful for supplementing light-mild-oily categoriesnot always available from marine fisheries. Otherlake fish can be substituted for traditional lean,mild marine fish without compromise. Walleyeand yellow perch are highly regarded by mid-western seafood consumers among higher pricedlean species. A survey of restaurant managers inthe Midwest indicated that walleye and yellowperch outsell halibut, a comparably lean, high-valuemarine species. Although customer demand for yel-low perch or walleye in restaurants is highest inthe summer, both products are served year round,despite the fact that the yellow perch commer-cial fishery is seasonal. Typically, restaurants pre-fer to select fillets when purchasing yellow perchand walleye. A recent study conducted at the OhioState University assessed how well consumers likedyellow perch in comparison to its major marketcompetitors, walleye, ocean perch, and importedEuropean zander. Although consumers were ableto detect differences between the four species of



Freshwater Fish 165

restaurant-style deep-fried fish, they liked themall equally with the exception of walleye whichwas rated somewhat lower. Interestingly, restau-rants in the Minneapolis/St. Paul region of Min-nesota were investigated by the Food and DrugAdministration (FDA) in 2004, when they werereported to be serving imported zander underthe name of walleye on their menus. Other fresh-water fish including smelt, suckers, sheepshead,and several other inexpensive fish are consideredfine eating and serve to round out product linesat lower cost than many comparable saltwaterproducts.

Off-flavors

When comparing flavor of fresh products, few dis-tinctions can be made between freshwater and salt-water species. However, earthy, musty, or weedyoff-flavors, when they occur, are encountered pri-marily in freshwater fish. These flavors occur moreby season and location than by species.

Regional consumer bias against certain fish maybe related to poor experiences with local supplies.Even fish normally in high demand such as walleyemay accumulate a “muddy” flavor at times, whilethe same species caught in another location may beunaffected.

The organic compounds geosmin and 2-methyl-isoborneol are produced by certain microorganismsand algae and are readily absorbed by fish, lendingdisagreeable flavors and odors to their flesh. Fishneed not ingest the plants to become tainted butprobably pick up the compounds from the watervia the gills and epithelial tissues. Other off-flavorscan be traced to decayed organic matter or, rarely,chemical contamination.

Objectionable flavors appear most commonly infish taken from shallow, weedy lakes and slow-flowing streams. Large bodies of water typical ofmost commercial fisheries are less affected.

Parasites

Parasites may be found in nearly all saltwater andfreshwater fish, often appearing as cysts or wormsin the flesh or viscera. They are characterized bycomplex life histories typically requiring one ormore intermediate host(s). Only parasites that need

both cold-blooded and warm-blooded animals dur-ing their life cycles are capable of infecting humanswho consume them in fish.

Saltwater seafoods may contain roundworms(nematodes) capable of causing severe but tem-porary digestive upset in humans. The FDA hasexpressed concern that pathogenic nematodes maybecome a problem because of the increased popu-larity of raw or lightly marinated fish.

Perhaps due to the proximity of freshwater envi-ronments to many warm-blooded animals, fresh-water fish may represent a greater health concernthan do saltwater fish. Also, nonpathogenic butunsightly infestations can be especially trouble-some to firms marketing affected products. Tape-worms and flukes occasionally infect consumers ofraw freshwater fish.

Northern pike, walleye, and burbot from thenorthern Midwest United States have the highestincidence of tapeworms. Complete coagulation offish muscle by cooking, pickling, or salting killsharmful parasites and accounts for the scarcity ofclinical cases in the United States. In most cases,frozen storage also destroys parasites. To preventthe migration of roundworms from the viscera tosurrounding meat, the fish should be thoroughlyiced and problem species marketed in evisceratedforms.

Contaminants

Pesticides, heavy metals, and other contaminantsin fish flesh have adversely affected regional fish-eries around the world. The US freshwater indus-try has been affected by regulatory action and byconsumer response to a list of chemicals and tradenames, including mercury, DDT, PCB, polybromi-nated biphenyl (PBB), dieldrin, and Mirex.

An estimated 5000–10,000 new chemicals are pro-duced each year, of which 1000 are introducedinto commerce. To protect consumers from possi-ble harmful effects, the Toxic Substance Control Actof 1976 requires that certain classes of chemicalsbe screened for toxicity before they are cleared foruse. In addition, it allows for federal regulation ofthe production and application of these chemicals.More recent legislation has strengthened enforce-ment capabilities. Once chemicals are in use, theFDA establishes and enforces limits on the amountsof certain substances that may appear in foods.




State departments of commerce, health, and nat-ural resources also commonly enforce measures toreduce public exposure to contaminants.

Although new contaminants in fish are identi-fied periodically, monitoring programs have docu-mented reduced concentrations of several of thesesubstances in recent years. As mentioned, few prod-ucts are currently banned from the marketplaceby legislation. Concerned consumers should knowthat commercially sold fish are routinely evaluatedfor major contaminants. Sport fishermen, who mayeat considerable quantities of problem fish with-out the benefit of such sampling, are at greaterrisk.

Selected species

Whitefish

Whitefish, which account for a significant portion ofthe trade in inland markets, is a collective name forcertain members of the Salmonidae family includ-ing true trout and salmon. They are characterizedby an adipose fin (a small rayless projection behindthe dorsal fin), a small delicate mouth, white flesh,and mild flavor.

Lake whitefish

Virtually all the whitefish sold under the name arelake whitefish (Coregonus clupeaformis) (Figure 14.1).A large, relatively oily whitefish, they grow to morethan 5.5 kg (12 lb) but average 0.91–2.27 kg (2—5 lb).They are found from New England to Minnesota

Figure 14.1 Lake whitefish, the primary species sold aswhitefish.

and north to the Arctic and Alaska. In recent years,Canada has increased its percentage of the catch asfishermen work the deep cold lakes of the north-central provinces and Northwest Territories. Theyproduce about 9.1 × 106 kg (20 million lb) each yearby fishing gillnets even under thick ice.

Lake whitefish are marketed whole, dressed,chunked, and filleted. The roe is fine in texture andremains tender when cooked. Market demand isstrong for eggs processed as “golden” caviar orwhitefish caviar. Although commonly sold fresh,large quantities of frozen, smoked, and canned lakewhitefish (combined with other species as gefiltefish) are also distributed.

Chubs (lake herring)

Several species of small whitefish are marketed inthe United States as chub, especially when drawnand smoked. Among biologists, “cisco” is the moreuniversally accepted name for this group. Fish soldas “lake herring,” “tullibee,” or “cisco” are usu-ally Coregonus artedii. Other chubs, some of whichare threatened or extinct, include deepwater cisco(Coregonus johannae), longjaw cisco (Coregonus alpe-nae), shortjaw cisco (Coregonus zenithicus), short-nose cisco (Coregonus reighardi), and blackfin cisco(Coregonus nigripinnis). Additional market namesinclude bloater and grayback. Sometimes, the termchub implies a smoked product because it is themost common market form. Seafood suppliers andbuyers should communicate clearly, due to confus-ing whitefish nomenclature.

Other whitefish

Round whitefish or menominee (Prosopium cylin-draceum) is a common resident to cold lakes ofnorthern New England, the Great Lakes, andCanada. Compared to some members of the white-fish family, round whitefish is lower in oil contentand, as the name implies, round in cross section. Itis smaller than lake whitefish and finds only lim-ited, usually local, markets despite desirable eatingqualities.

Inconnu or sheefish is a very large whitefish ofnorthwestern Canada and Alaska. They are foundin large lakes and streams where they migrateto sea. Anadramous (migratory) individuals may



Freshwater Fish 167

Figure 14.2 Yellow (freshwater) perch.

reach 27.2 kg (60 lb); landlocked specimens aresomewhat smaller. Inconnu (French for unknown)possess white, oily, mild flesh but find few buyersin the United States, possibly due to limited experi-ence with the species. Perhaps 2.27 × 104 kg (50,000lb) are shipped to the lower regions of the UnitedStates.

Yellow perch

Yellow perch (Perca flavescens) is among the mostvaluable species in the freshwater industry, remain-ing a mainstay of many US and Canadian fishingports (Figure 14.2). In recent years, imports fromCanada have dominated the market. The high valueof Ontario landings is largely attributed to perch.Although, landings of yellow perch from Ohio’shistorically important Lake Erie fishery were spo-radic during the 1990s, they have steadily increasedto reach the 2008 level of 1.95 million lb of fish witha value of $4.4 million.

Yellow perch are true perch (family Percidae)closely related to walleye and sauger. They havelittle in common, either taxonomically or gas-tronomically, with white perch, ocean perch, ora dozen other species commonly referred to as“perch.” The term lake perch may refer to eitheryellow or white perch. Yellow perch are widely dis-tributed from South Carolina north to Nova Sco-tia and west to the Great Lakes and west-centralCanada.

Although yellow perch average under 0.454 kg(1 lb), their simple skeletal structure and small vis-ceral cavity lend them to commercial filleting, soldfresh or frozen. Other forms include whole and,less commonly, breaded and frozen. Yellow perchare recognized by the presence of two spiny dorsal

fins, a greenish to yellow body with dark verticalbands, and yellow to orange pelvic fins. The fleshis firm, white, lean, and mild but distinctive. Well-handled fresh or frozen perch generally retain qual-ity longer than many species. Gillnetters find theyhold up well in their nets and are slow to developsigns of enzymatic softening.

Walleye

Another member of the perch family, walleye(Sander vitreum), is similar to yellow perch bothin general appearance and in eating quality. Theyare larger however, reaching 4.5 kg (10 lb) or morealthough averaging 0.9–1.8 kg (2–4 lb). Their backis dusky, grading to bronze-gold on the sides. Longrecognized for their culinary quality, walleye wereknown as salmon to early settlers. The meat is finetextured, firm, white, lean, and mild.

Its natural range extends from North Carolina toNew England, west to the Rocky Mountains andnorth to the Hudson Bay. Largely protected as agame fish in the United States, most of the 5.45 ×106 kg (12 million lb) available are imported fromCanada. Small quantities are available from NewYork, Pennsylvania, and American Indian fisheries.They are available fresh or frozen, whole, dressed,filleted (skin off or on), and as breaded fillets. Theyalso appear as an ingredient of gefilte fish. Shelf-lifecharacteristics and fillet yield are similar to yellowperch.

Walleye are usually marketed under that name orwalleye pike in the United States but are recognizedas yellow pickerel by the Canadian government.Suppliers may list them as yellow pickerel, pike-perch, or yellow pike, although as a percid, walleyeare unrelated to pike or pickerel. As an adaptation tolow light levels, their eyes are naturally opalescent,which negates cloudiness as an indicator of quality.Blue walleye is a walleye color variant, possessinga gray to blue body instead of the typical goldenhue. They are almost certainly not true blue pike(Sander vitreus glaucus), a Great Lakes species whichappears to be extinct.

Sauger (Sander canadensis) is a close relative and,though somewhat smaller, nearly identical to wall-eye in appearance. Look for the absence of a whitetip on the lower lobe of the tail fin, characteristicof walleye. Sauger enter markets mostly as an inci-dental catch of the walleye fisheries. Eating quality




Figure 14.3 Lake trout, the largest of North American trout.

is similar to walleye and blue pike but is consideredby some to be slightly less desirable.

Lake trout

Lake trout, the largest of North American trout(technically, a char), are found in cool, deep lakesacross northern America (Figure 14.3). They areavailable from Canadian, Wisconsin, and Min-nesota sources and certain Midwest AmericanIndian companies fishing under treaty. Lake trout(Salvelinus namaycush) are also known as mackinaw,togue, namaycush, forktail, and Great Lakes trout.They average about 1.8–2.3 kg (4–5 lb) in the com-mercial catch but may reach 22.7 kg (50 lb) or more.Like whitefish and other salmonids they possessa small fleshy adipose fin on their back behind aspineless dorsal fin. They have large mouths andsharp teeth. Coloration is dull but distinctly markedwith light spots on a darker background.

Lake trout are among the most oily of commer-cial fish ranging up to 22% fat for the commonspecies. The closely related siscowet, or fat trout,may contain more than 50% fat. These deepwatertrout are only occasionally available on the market,usually in a smoked form. Until the late 1980s, about600,000 lb of siscowet were harvested annually. Arecent study revealed that there are over 600 mil-lion lb of this omega-3 fatty acid rich fish in LakeSuperior alone. Lake trout populations were dec-imated by the lamprey invasion of the 1940s and1950s. Current Great Lakes stocks are maintainedby ongoing stocking programs because current cul-tured varieties cannot reproduce naturally. Thereis some hope that the wild western brood stockwill help reestablish a self-sustaining population inthe future. A lake trout/brook trout hybrid knownas splake has been introduced and is harvested byOntario fishermen.

Smelt

Several small, slender species of fish may be calledsmelt but the one most commercially important isthe rainbow smelt or lake smelt (Osmerus mordax).It is a silvery to greenish fish usually under 20.3cm (8 in.) long with a rather large mouth for itssize and characteristically sharp teeth, even on itstongue. Its small silvery scales are easily rubbedoff. An anadromous fish by nature, living in salt-water and entering freshwater streams to spawn,it has adapted so well to freshwater habitats thatit is often considered a freshwater fish. Smelt arewidely distributed in the Great Lakes region andin the Northeast where they are taken by a varietyof gear including small mesh gillnets, pound nets,and trawls. Some states manage smelt as forage forgame fish and do not issue commercial fishing per-mits. Much of the supply comes from Canada.

Often labeled as fatty fish, smelt are actuallyquite lean, about 2% fat, although a much moreoily cousin, the eulachon or Columbia River smelt,is locally popular in the Northwest. Some buyersconsider lake smelt better than Atlantic or Pacificspecies. Smelt are available nearly year round eitherfresh or frozen, headed-and-gutted, or whole. Theyare nearly always breaded and fried, and eatenbones and all. Although shelf-life properties aregenerally good, the delicate flavor and texturethat smelt are noted for are quickly lost whenmishandled.

Catfish

Originally native to the Mississippi, Missouri, andOhio River drainage, blue catfish (Ictalurus furcatus)have been widely introduced throughout the coun-try, and are most prevalent in central and south-eastern United States. They are the largest catfishspecies in the United States with trophy fish reach-ing sizes well over 100 lb. Highly prized by anglersfor their firm, white, mild-flavored flesh and fight-ing spirit, these fish are also harvested commer-cially in numerous states including Louisiana, Vir-ginia, Kentucky, Arkansas, Tennessee, Illinois, andTexas. For many years, the largest commercial har-vest has occurred in Louisiana; however, that har-vest has gradually dropped from 4.2 million lbin 2000 to 2.8 million lb in 2008. Also known asthe humpback blue, forktail cat, chucklehead, and



Freshwater Fish 169

Figure 14.4 Channel (or spotted) catfish.

Fulton cat, these fish are primarily processed andsold in local markets.

Channel catfish (Ictalurus punctatus) are mostlyfarm raised, but fisheries remain in the Great Lakes,in Mississippi drainage, and in some coastal trib-utaries of the East and Gulf coasts (Figure 14.4).Flathead catfish, white catfish, and bullheads arealso available. In 2008, Louisiana reported the high-est catches of catfish, with landings of 578,000 lband 325,000 lb for channel catfish and flathead cat-fish, respectively. Catfish tolerate low oxygen lev-els and are one of the few fish sometimes mar-keted alive. They may be held in drums or tubson fishing vessels, and then transferred to aeratedtanks at shore-side facilities. They are also mar-keted dressed (headed-and-gutted, skinned) and,to a lesser extent, filleted or steaked.

Other species

Small but regionally significant quantities of otherwild harvest freshwater fish are also caught inNorth America, most finding local or ethnic mar-kets. Pike are large, toothy fish that frequent north-ern lakes and streams from New England to theMidwest and most of Canada. The northern pike(Esox lucious), the only species supporting a com-mercial fishery, grow to 11.4 kg (25 lb) or more,but 1.8–3.2 kg (4–7 lb) is more common (Figure14.5). They are recognized by their long, slendershape and greenish skin covered with yellow orcream-colored oval spots. Supplies come primar-ily from Canada since they are protected in theUnited States. Much of the catch is exported toEurope where the same species is also native butexists in numbers too low to satisfy the strongdemand. The name, pike, is occasionally confusedwith market terms for walleye, yellow pike, bluepike, and yellow pickerel. In fact, walleye are some-

Figure 14.5 Northern pike.

times called walleye pike. Such confusing nomen-clature is unfortunate because the two species areunrelated and dissimilar in appearance and eatingquality.

Northern pike are a lean (1–2% fat), very firmand mild fish containing numerous Y bones (forkedintermuscular bones). They are sold whole or cutinto most market forms, fresh or frozen.

Carp (Cyprinus carpio) is popular in many ethniccenters (Figure 14.6). Nearly 13.6 × 106 kg (30 mil-lion lb) are harvested commercially in the UnitedStates each year, mostly from the Mississippi Riversystem, the Great Lakes, and from states issuingpermits as part of fish control programs. Becauseof a propensity for concentrating geosmin com-pounds, they are best when harvested in winteror from bodies of water where algae are not a prob-lem. The flesh is often oily, ranging from 2% to 25%fat, and has a distinctive but pleasant flavor. Carpare usually marketed whole or in finished products,such as gefilte fish.

White perch (Morone americana) is both a fresh-water and saltwater species (Figure 14.7). It is nota perch at all but a small relative of the stripedbass and sea basses. Lake Erie’s white perch popu-lations have increased in recent years as large num-bers have migrated from the Atlantic by way ofthe Welland Canal. The harvest has also increasedsomewhat in the Mid-Atlantic marine fisheriessince 1985. Fillets are sometimes sold as lake perch,

Figure 14.6 Carp.




Figure 14.7 White perch.

a name also used for the higher valued yellowperch. To add to the confusion, white perch isalso a market name for freshwater drum, otherwiseknown as sheepshead or freshwater croaker.

A closely related species, the white bass (Moronechrysops), is an important fish in the Lake Erie fish-eries both in Canada and the United States (Figure14.8). It resembles a silvery, panfish-sized stripedbass, having narrow dark stripes that run the lengthof the body. The average size is about 454 g (1 lb)although some individuals approach 1.8 kg (4 lb)especially in southern and southwestern reservoirswhere they have been stocked for recreational fish-ing. White bass produce boneless fillets of good eat-ing quality.

Suckers make up another family of freshwaterfish of some importance. The white sucker or fresh-water mullet (Catostomus commersoni) is probablythe most significant commercial species. Althoughharvested primarily in the Great Lakes, it is widelydistributed east of the Rocky Mountains. As withsome of the other suckers, it is well known for itsnumerous fine bones which limit market poten-tial. The fish are sometimes split and scored toreduce bone size, which then soften during cook-ing. Several processing plants have used this species

Figure 14.8 White (freshwater) bass.

to produce boneless minces. It is a drab green tonearly brassy-colored fish of about 1 to 1.4 kg (2–3lb). Other suckers include three species of buffalo(large fish resembling carp harvested in the Missis-sippi valley south of the Great Lakes); the longnosesucker; ten species of redhorse; two species of quill-back or carpsucker; the spotted sucker; and the bluesucker.

Other North American freshwater fish occasion-ally seen in the markets include crappie, vari-ous sunfish, freshwater drum, rock bass, burbot,lake sturgeon from Canadian sources, eel, bowfish,gar, paddlefish, and alewives (smoked or cured).The American paddlefish (Polyodon spathula), alsoknown as spoonbill cat or spoonbill sturgeon, pro-vides the roe for much of the “American sturgeon”caviar on the market. It is not related to either stur-geon or catfish. Most alewives, gizzard shad, andgoldfish are sold for commercial bait or industrialapplications.

As mentioned previously, Pacific salmon speciesstocked in the Great Lakes are tightly managed forrecreational purposes; however, significant quanti-ties are marketed. The State of Michigan awardsa contract for sale of adult salmon taken at weirswhere eggs and milt (the male’s sperm) are collectedfor culture, and Canada permits limited fishing.

Acknowledgments

Information contained in this chapter was providedby the following individuals: Ronald E. Kinnunen,District Extension Sea Grant Agent, Michigan SeaGrant College Program, Michigan State University;Mark Malchoff, Regional Extension Specialist, NewYork Sea Grant Extension Program, Cornell Univer-sity; Jeff Gunderson, Fisheries Agent, MinnesotaSea Grant Extension Program, University of Min-nesota; Fred Snyder and David Kelch, Ohio SeaGrant Program, The Ohio State University.

Further reading

Anonymous Variously dated. Food Fish Facts. A seriesby the National Consumer Educational Services Office,National Marine Fisheries Services, US Department ofCommerce.

Delwiche, J.F., R.E. Liggett, and G. Wallat. 2006. Consumerperception of cultured yellow perch (Perca flavescens)



Freshwater Fish 171

and its market ompetitors. Journal of Food Science 71(8):S579–S582.

Dore, I. 1982. Frozen Seafood: The Buyer’s Handbook. OspreyBooks, Huntington, NY.

Graham, K. 1999. A review of the biology and manage-ment of blue catfish. American Fisheries Society Sympo-sium 24: 37-49.

Harris, L., N. Kevern, and R. Kinnunen. 1984. Commercialfishing in the Great Lakes. Michigan Sea Grant CollegeProgram report.

Higashi, G. 1985. Foodborne parasites transmitted to manfrom fish and other aquatic foods. Journal of Food Tech-nology 39(3): 694.

McClane, A. and A. deZanger. 1977. The Encyclopedia ofFish Cookery. Holt, New York.

National Marine Fisheries Service. 2009. Personal com-munication from the national marine fisheries ser-vice, fisheries statistics and economics division. SilverSpring, Maryland.

Nettleton, J. 1985. Seafood Nutrition: Facts, Issues and Mar-keting of Nutrition in Fish and Shellfish. Osprey Books,Huntington, NY.

Riepe, R. 1999. Marketing seafood to restaurants in theNorth Central Region. North Central Regional Aqua-culture Center Fact Sheet Series #110.

Seagran, H., S. Smith, and H. Buettner. 1976. Lake andriver fisheries. In: From Industrial Fisheries Technology,ed. M. Stansby. Krieger, Huntington, NY.

Tainter, S. and R. White. 1977. Seines to Salmon Charters.Extension bulletin E-1000, Michigan State University.

Webliography

Fisheries and Oceans Canada. 2006. Commercialfisheries landings. http://www.dfo-mpo.gc.ca/stats/commercial/land-debarq-eng.htm (accessed April 23,2009).

Documents

The Seafood Industry (Species, Products, Processing, and Safety) || Freshwater Fish