In all the oceans of the world, fish have abounded for countless millennia, most of them doomed to spend their whole lives swimming until they are eaten by bigger fish. Shakespeare put it well when he had the Third Fisherman in Pericles ask how the fishes live in the sea, to which the First Fisherman replies: "Why, as men do on land; the great ones eat up the little ones." Only a tiny minority of fish are sufficiently large or well protected to escape predators. Even they may fall prey to the latest predators to arrive on the scene—to wit, ourselves.
Until human populations began to increase at an exponential rate, and until methods of preserving and transporting foods approached their present level of sophistication, mankind's need for food had little impact on the vast resources of the oceans and seas.
Radical change in this situation began in medieval times, when European fishing boats reached the rich codfishing grounds in the northwest Atlantic. Salting techniques, as well as wind-drying, meant that huge quantities of fish could be processed in, for example, Newfoundland and then brought back on the long voyage to Europe. Meanwhile the ascendancy of the Roman Catholic church, with its numerous fast days, in an increasingly populous Europe caused a sharp increase in demand. Salt cod became, and remains to this day, a staple food in the Iberian Peninsula, the south of France, and Italy.
In more recent times fishery techniques evolved swiftly, culminating in the modern fishing industry. This has such deadly accuracy in finding shoals of fish and in catching them, and such advanced means of freezing, that overfishing occurs wherever effective controls have not been instituted. These controls are hard to establish and maintain. The initial impact on fishermen is adverse. Boats have to be laid up; an appreciable number of fishermen lose their livelihood; fishing ports where many people earned a living by servicing the fleets risk falling into a slump. However, if supplies are to be maintained, fish stocks must be allowed to survive in viable number and every ancillary means, notably more and better fish "farming," must be developed.
Considering the merits of fish as a food, nutritionists give it high marks. Sea fish, like freshwater fish, are an excellent source of protein, but have additional health benefits to offer, for example in the form of vitamins, iodine, and phosphorus. Joyce Nettleton (1987) gives a comprehensive survey of the vitamins in which seafoods are rich, including pyridoxine, niacin, and vitamin B12.
So far as fat and oils are concerned, there is a major distinction between what are sometimes called "white fish" (for example, the cod family and flatfish) and what the Spaniards refer to as pescado azul, meaning blue fish. The latter category includes the powerful surface swimmers such as tuna and mackerel, which roam at speed over deep waters and whose coloration is usually dark blue with a pale underside, to make them inconspicuous to predators from above or below. Their lifestyle calls for very strong muscles, creating a need for more oil in their bodies. As a group they may be categorized, less romantically than in Spain, as "oily" fish.
There is, as one would expect, no sharp dividing line between oily and nonoily, but a spectrum with "white fish" clustering at one end and "blue fish" at the other. The oil content may be as high as 15 percent (sardines at certain times of year) or as low as 1 percent or even less (flatfish); in general, a content of over 5 percent would be enough to rate a fish as oily. The oily fish contribute more fat to the diet, which makes dieters wary of them, but the fish oils are in fact highly beneficial from several points of view, so much so that people who do not include oily fish in their diet may be advised to take fish oil supplements. Joyce Nettleton provides a clear and full exposition of the merits of the omega-3 fatty acids (present in seafood because it is made in the first place by the phytoplankton in the oceans) and their special virtues.
Summarizing the health benefits of eating sea fish, Nettleton points out that they are low in calories, that most of them are very low in fat, while all are low in saturated fat. The long-chain omega-3 oils have been shown to protect against heart disease and some other afflictions, and are definitely low in cholesterol and in sodium. She refers also to the vitamins and minerals mentioned above, explaining that dark-fleshed fish have especially abundant amounts of iron, and that seafood is the best source of many trace minerals such as zinc, selenium, fluoride, and copper.
Sea fish in general, and "white fish" in particular, are usually easy to digest, partly because they have very little connective tissue. Indeed certain white fish with delicate flesh (for example, whiting) are traditionally recommended as invalid food. Moreover, they can be eaten cold as well as hot.
Fish bought from a fishmonger or in a supermarket are usually from a limited number of familiar species, and bear labels saying what they are. But for some people, for example, travelers and expatriates, choosing and identifying fish can be a problem; and of course a sure means of identification is a necessity for all who are involved in the international fish trade. In these other situations there is potential for confusion, arising mainly from the sheer multiplicity of edible species. There are not many sorts of meat in common consumption, and the number of species of bird which are widely eaten is limited. But the number of edible fish is very large, and even in one market there may be scores available.
The number of species is quite enough by itself to cause perplexity, but there are aggravating circumstances of two kinds, which compound confusion. One source of confusion may be regarded as natural and viewed with tolerance. This is the confusion caused by the fact that even within one language, indeed sometimes within one dialect, the same fish will have a range of different names. These reflect local practice in small coastal communities, which were often isolated from each other in the past by poor overland communications. In Italy, for example, the common grey mullet, Mugil cephalus, has more than forty different names.
The other sort of confusion applies to European languages, especially English, and is a by-product of colonization. Its effect is quite the contrary—to make it seem that there are fewer families or species of fish in the world than there really are. What happened was that early English colonists, to take the main culprits as an example, applied familiar but inappropriate names to the species that they encountered in the New World, Australasia, and elsewhere. Understandably, they called the fish they found overseas by names they already knew, on the basis of a real or fancied resemblance. This could sometimes work satisfactorily. English settlers in North America, familiar with salmon at home, found salmon there too, not always of the same species, but at least of the same family (Salmonidae). But sometimes the results were less happy. The fish that settlers in Australia called salmon are not akin to the salmon of the Northern Hemisphere, while the so-called "Murray cod" of Australia is not a cod and is not even a sea fish.
In a situation affected by so many causes of confusion, it is only the scientific names of the species that can provide certainty. Fortunately, international and national authorities have been working for some time to rationalize commercial names for the species, and more and more authors are adopting the practice of identifying the species they mean, if there is any room for doubt, by its scientific name as well as by popular ones. The work of the Fisheries Division of the Food and Agriculture Organization (FAO) of the United Nations has made, since the 1950s, an outstanding contribution to clarification and precision.
In any case, and in practical terms for consumers, the sort of confusion described above is not the norm; nor does it necessarily cause bad results. A number of species occur around the world, for example, Xiphias gladius, the swordfish, and Mugil cephalus, one of the grey mullets. Nearly all the families of fish have representatives in both the great ocean areas, and these representatives differ little from the cook's point of view (although the scientists properly distinguish between them by counting their fin-rays or examining their air-bladders). Thus the famous red mullet of the Mediterranean have close relations in the Indo-Pacific; but the latter are known as goatfish, and treated by Asian cooks in a different way, and for this reason people often fail to see the connection.
There are certainly wide variations in the manner of fish consumption. In many European countries it would be normal to serve a small fish whole and a larger fish in full portions (say, 5 oz [150 g]) either separately (to be followed by a vegetable, as often in France) or with vegetables. In Britain, for example, the tradition is that fish is either what you have with chips or something to be served, like meat, with "two veg." But these traditions, although spread around the world to some extent by the influence of France and of the British Empire, are not widely shared. In most parts of the world, especially Asia and Africa, fish is more likely to be one constituent of a combination of different foods, or an element in a onepot dish, or something that accompanies pasta, or rice, or goes into fish balls, fish puddings, or pies, or is part of a soup-plus-fish-stew dish. Many such modes of presentation produce delicious results, and make a relatively small quantity of fish "go further."
This last point has an even wider application. In most countries of Southeast Asia a product known as fish sauce (nuoc mam in Vietnam) plays an important part in the diet as a source of protein. These sauces are prepared by fermenting large quantities of small fish, usually such as would serve no other purpose, and straining the liquor which this process generates. This liquid resembles soy sauce, both in appearance and in its composition. Added to rice or other savory dishes, it enhances both flavor and nutritional qualities.
The preparation of fish sauce is one example of how fresh fish can be turned into a product that will keep for a long time. The various sorts of fish paste are others. The fish used for these purposes lose their identity, whereas those that are dried or salted or smoked (or undergo all three processes) can still usually be seen for what they are. They may also become better to eat, or anyway come to be preferred, as in the case of the kipper (salted, dried, and smoked herring) or the salt cod mentioned above, which has for centuries been a staple food in the Mediterranean region, or the smoked salmon that is now an almost inevitable feature of restaurant menus. That freshwater fish are less often subject to preservation processes may simply reflect their greater availability—trout can be found in the river (or, nowadays, fish farm) at any time and marketed on the same day, whereas many marine fish can only be harvested by distant fishing boats.
Some species of fish are purely freshwater, others are entirely marine. But the division is not clean-cut, for there are species, and important ones, of sea fish that can, and in some instances must, move from one environment to another. In many instances species that live most of their lives in the sea have to go up rivers to spawn. They are called anadromous. Some famous examples are salmon, shad, and eel. However, the eel differs from the other two in that its stay in freshwater covers the greater part of its life. It is a marine fish only in Act One of its life, when it drifts in larval form across the Atlantic from the Sargasso Sea to the river mouths of Europe, and in Act Five, when it goes back into the sea years later and sets off on its arduous journey back to the Sargasso Sea, there to spawn and die. Indeed, although the sea thus provides both its birthplace and its grave, the eel counts for many purposes as a freshwater species.
If only because of this sort of anomaly, there is little point in asking which are better, freshwater or marine species. It is true, however, that there is some division of opinion, misguided or not, about their respective merits. In inland countries and regions the former may be preferred because they have been accessible for much longer and are established as traditional dishes. Where sea fisheries are established, the reverse is usually the case. However, there are exceptions. To take two examples, people in Bangladesh and Burma prefer freshwater fish and use spices, notably ginger, to mask the marine flavor of sea fish, the very flavor that people in many other countries prize.
Even within the category of sea fish it is interesting to note that some people believe that fish from cold waters are better, the idea being that they lead a particularly active and healthy existence, whereas fish from semitropical or tropical waters laze about and have a less firm consistency. If this belief were to be investigated, it would probably turn out to have little or no foundation.
There is one respect, however, in which sea fish from colder and warmer waters do differ significantly. In cold waters it is usual to find a relatively small number of species, normally existing in huge populations. In tropical or near-tropical waters, on the other hand, there is a very great diversity of species, but few of them are anything like as numerous as those of cold waters.
However, as usual when trying to make generalizations about sea fish, one finds that this contrast is not entirely valid. Some species of tuna are among those which pass, apparently without any problem, from cold to warmer zones and back again. The whole great family of tuna is extraordinary in other ways too. One is the degree of ceremony, drama, and cultural significance with which the fishery for them in the Mediterranean is invested. The tuna traps, of which about a hundred were still operating in the 1960s, were certainly in use in classical times, and some authorities believe that they date even further back. Essentially the trap consists of a long net stretching out to sea, across the expected path of the migrating bluefin tuna. This net diverts the fish into a series of pounds, each of which leads into the next, and finally into the death chamber. There, a net stretched across the bottom can be hoisted up periodically, when there are enough tuna present, bringing them up to a position where they can be taken with gaffs. The fishermen jump in to deliver the death blows. The scene is bloody and to spectators horrifying. The Greek tragedian Aeschylus likened it to the slaughter of the Persians at the battle of Salamis. In Sicily, where the event is called the mattanza, and in other places around the Mediterranean the capture and slaughter of the tuna is an event that has more significance than a mere fishery episode; it has served to reaffirm, annually, the cultural identity of the whole community.
In contrast, in most communities in the Western world, the catching and killing of sea fish take place completely offstage; indeed, many of them finish up as neatly trimmed fillets whose identity would be a mystery unless revealed by the label. This distancing of the scene in a dining room from that on the deck of a trawler has left people without the feeling for fish so eloquently expressed by classical writers. This was still evident in nineteenth-century writings such as the Reverend Badham's Prose Halieutica: Ancient and Modern Fish Tattle. However, the Greek word in the title is a direct echo of the Greek poet Oppian's Halieutica ; Badham wishes his readers to know that his own picture of the fishy world, in which the personalities and habits of so many of the fish are described, stems from classical times. If modern writers allude at all to these aspects of the fish, it is only in terms of the struggle fishermen are perceived as waging against the fish, so that the attributes of the fish are generally restricted to terms such as "wily," "valiant," "predatory," etc.
It was in classical Greece that the earliest known guide to finding good food was composed. The author was Archestratus. Enough of the work survives (and has recently been published in translation) to demonstrate the point that is relevant here: that more attention was paid to good sources for fish of the highest quality than to any other category of food. The recommendations were not just of the "Syracuse is the best place to buy fish" variety, but were completely specific. Thus connoisseurs were directed to the straits of Rhegium for sea-caught eels and to Ephesus for a fat gilthead bream. This argues a greater public awareness of quality in fish, and of the various species, than is common nowadays. It is of course relatively easy to have this commendable awareness in a small city-state with an economy based on slave labor and ready access to freshly caught fish. In the modern world, with much of the population inhabiting huge conurbations, far from the fishing ports, and relying in the main on what supermarkets find it economic to provide (there are far fewer fishmongers nowadays), it would be fruitless to expect to find many connoisseurs of fish. Nevertheless, there is one favorable trend, noticeable in the last decades of the twentieth century and the first of the twenty-first. This is the gradual recognition of fish that qualify for an "organic" label as desirable, leading to greater appreciation of quality in fish. This is accompanied by a growing proliferation of cookery books whose recipes frequently call for a particular species of sea fish, and not necessarily one which is in common supply. To take one example, what has happened to the anglerfish (often called monkfish and, in America, goosefish) is instructive. It used to be spurned on both sides of the North Atlantic and was appreciated only in the Mediterranean. Now it has become a valuable and relatively expensive kind of fish, and recipes for it abound. The ability to make greater use of species that had been underexploited in the past is one necessary element in maximizing the harvest of the seas, to the benefit of all.
Archestratus. The Life of Luxury. Translated with introduction and commentary by John Wilkins and Shaun Hill, Totnes, Devon, U.K.: Prospect Books, 1994.
Badham, Rev C. David. Ancient and Modern Fish Tattle. London, 1854.
Davidson, Alan. Mediterranean Seafood. Berkeley, Calif.: Ten Speed Press, 2002.
Davidson, Alan. North Atlantic Seafood. Berkeley, Calif.: Ten Speed Press, 2002.
Food and Agriculture Organization of the United Nations. Species Identification Sheets. Rome: FAO. Published as a continuing series since the 1970s and now covering most families and most fishing regions.
Nettleton, Joyce A. Seafood and Health. Huntington, N.Y.: Osprey Books, 1987.
Wheeler, Alwyne. Fishes of the World. London: Ferndale, 1975.