Man and the Sea. Resources for Society’s Future

In obtaining food from the sea, man is continuing a process begun in the hunting and gathering stages of his history, although modern technology has taken much of the element of “luck” from fishing.

It appears that the sea is a virtually untapped food source, especially of protein foods. Fishermen are now taking less than 50 million tons of fish a year, while the amount available has been calculated to run as high as 100,000 million tons a year.

As well as using new methods of fishing such as echo-sounding and sonar beams, new uses are being found for the fish. One apparently important one is fish flour, a solvent extraction of fish protein: FPC or fish-protein concentrates. This is being developed in a number of places, and the US Bureau of Commercial Fisheries has devised a process for obtaining FPC from hake. The concentrate, which contains 85 per cent, protein, is highly nutritious, and practically tasteless and odourless. The idea is not that FPCs should be used as food in their own right, but as additives to the traditional dishes in areas where diets do not contain sufficient protein.

Another idea is to make use of the kinds of fish not yet exploited commercially, such as coley, redfish and dogfish, and to serve them in different and novel ways. School and industrial canteens have been used as guinea-pigs and the fish was found to be “perfectly acceptable”. Apart from the obvious advantages, the use of new and unknown kinds of fish will lessen the pressure on the traditional fishing grounds.

New Kind of Harvest
Many scientists believe there is a far richer source of sea food in plankton — the microscopic plants and animals that swim in the water and form the basis of all animal life in the sea. The plankton is eaten by small fish which in turn are eaten by bigger fish, and anywhere along the line man steps in and catches some of the bigger species. A way of eliminating the middle man, so to speak, would be to harvest the plankton directly. In this food chain, it takes about 100 lbs. of plankton to create 10 lb. of herring which creates 0.1 lb. of tuna fish.

The whale, one of the few mammals living in the sea, has a diet which consists entirely of plankton, which it scoops up as it travels through the water, and by doing so has drastically shortened the food chain. An idea would be to have nuclear-powered man-made whales, ships that would pour a steady stream of plankton into their holds as they ply the oceans.

Herds for Food
Very little farming of the sea has been done as yet, that is, to consciously rear and harvest fish, etc. The cultivation of the yellowtail is quite exclusive to Japan, although this cannot be considered true “farming” because the fish are taken when young from out at sea and are then fattened in enclosed areas of the sheltered inland sea.

The real breakthrough for marine farming came with the recent developments in stocking marine fields with domestically hatched and reared marine animals. There are still many problems to be overcome, but this opens up the possibility of achieving the same kind of revolution as Robert Bakewell achieved in livestock breeding in England in the 18th century. The specially-bred animals would be reared in marine fields. One of the most successful such ventures has been the rearing of the Japanese prawn. Methods were devised for hatching eggs obtained from female prawns brought in by fishermen.

In this way two types of fishery could develop. On the high seas fleets could cull the wild fish populations — somewhat as some African countries “crop” the wild animals in their National Parks; and nearer home, the marine farmer would cultivate “domesticated livestock” in the inshore pastures of territorial waters.

Scientists are now also turning to the sea as a source of drugs, and it seems as though it is a practically untapped source of potentially useful medicines, especially of further antibiotics.

Fit to Drink
Water is said to be in short supply in relation to the domestic, agricultural and industrial needs for it. Under capitalism much water is wastefully used, but even so very little is taken directly from where most of it is: the sea. The oceans and seas hold about 97 per cent, of the world’s stock of water, and unlike most other natural resources the sea is self-renewing — all the water eventually ending up in the sea, in a series of events known as the water cycle.

Although work is being done to develop strains of crops which are resistant to salt water, most of the water used by man needs to be fresh. So to obtain water from the sea, all the dissolved minerals have to be removed — desalination. There are generally three different types of methods, of which distillation is the major and oldest process. Desalination plants are in use in a number of places over the world. In Israel, where present water supplies fall short of the potential demand by as much as 80 per cent., the impetus for developing methods of desalting the sea and brackish waters derives from the question of survival rather than commercial interest. The Israelis have carried out an extensive research programme which they hope will lead them eventually to emancipation from the threat of serious shortages of water, and already have several desalting installations in operation.

Power from the Tides
The oceans are a huge source of restless energy deriving from winds, waves, tides and currents. The effects of these are sometimes disastrous, as in January 1953 when serious flooding in eastern England and the Netherlands caused extensive damage and resulted in the deaths of 2,107 people. Fortunately the oceans do not always expend their energy in such destructive ways, and can be put to man’s use. As tides are relatively reliable they can be harnessed to turn turbines and produce electricity. A place with a high tidal range is obviously necessary for the location of a tidal power station and there are only about two dozen suitable places in the world, of which about ten have been seriously considered.

The major possibility in Britain is the Severn Estuary, and a power station from Cardiff to Western-super-Mare has been estimated as being able to supply one-twelfth of the United Kingdom’s power, and an additional road between Wales and England. The French were the first people to build a tidal power station. It straddles the Rance Estuary in NW France, and is designed to produce 240 megawatts of electricity, enough for a city of about 500,000 people. Receiving the direct force of the great Atlantic tidal wave this coast also has remarkably regular tides, and during the spring tides has a range of 42 feet. At the height of the spring tide flow, water comes rushing up the estuary at a rate of nearly 4 million gallons per second. Even so, the power station’s output is only a small proportion of the 180,000 megawatts of energy thought to flow from the Atlantic into the English Channel, and is almost insignificant beside that of world tides — 1.5 million megawatts.

Resources Galore
For every statistic prophesying doom for the world in terms of mineral resources, there is another to contradict it. The ecologists contend that we must use the resources of the world austerely, to make them last — at least until other substances can be found to take their place. However, commerce lives only for the day: in case the high-grade deposits on the land really are becoming exhausted, the mining companies have their eyes on (and pockets ready for) the mineral wealth in the sea and on the sea bed.

The beautiful thing about the sea is that minerals are being deposited there faster than man can hope to collect them. Every year rivers flowing from the land add about 3,300 million tons of material which eventually comes to settle on the ocean floor. Nearly 4 million tons of meteoric and other materials rain down from outer space. In fact the oceans form a global chemical plant, in which practically every chemical is being processed and finally stored: providing a renewable resource which will last beyond the foreseeable future.

Dr. John Mero has presented some astonishing estimates of the various minerals in one type of deposit, manganese nodules, found on the floor of the Pacific Ocean. According to him, the nodules hold enough aluminium to supply man for about 20,000 years, cobalt for 200,000 years, copper for 6,000 years, manganese for 400,000 years and zirconium for 100,000 years. (The figures are based on 1960 rates of consumption.) In addition, these nodules are estimated to contain 207,000 million tons of iron, which is almost twice as much as the present land resources which are expected to last at least 250 years. There is also estimated to be nearly three times as much lead as the present land reserves which, we are told, could be exhausted by 1988. And the list goes on; but the store is hardly touched by man. Manganese nodules are not restricted to the Pacific. They are also found in the Atlantic and Indian Oceans. They were first dredged from Scottish lochs!

Extracting Minerals
The problem is that the average depth at which they are found, about 13,000 feet in the Pacific, makes conventional dredging out of the question. Dr. Mero suggests that giant dredgers controlled from the surface could sweep up the nodules from the ocean floor. But while land reserves are still sufficient there is as yet no real incentive to take these minerals from the oceans, especially as the cost would be in the order of some £12 million or more. A further problem quoted was that America might find herself in the “embarrassing situation of having a surplus of some minerals”.

Red clay sediments on the ocean floor contain enough copper and aluminium possibly for a million years, but again are difficult to obtain. However, small amounts of sand, gravel, shells, limestone, tin, gold and diamonds are all dredged from the sea in shallow coastal regions. In 1966 over 6 per cent, of this country’s gravel and sand came from the sea bed. Apart from their direct use in construction works, sand and gravel taken from the sea also play a part in land reclamation.

Only three dissolved chemicals are extracted from sea water on a commercial scale: salt, magnesium and bromine. Today as much as a third of the world’s production of salt comes from the sea, the heat of the sun being used to evaporate the water as it has been done for centuries. The production of salt in this way led to the extraction of magnesium from the sea in the nineteen-thirties, and today most of this metal comes from sea water or brines.

For the Future
Natural gas, oil and molten sulphur can be piped up from the underlying rocks of the sea bed, and some 200 drilling rigs are at this moment probing the continental shelves in various parts of the world in search of these minerals. It is very difficult to gather figures as to the estimated amount of oil under the sea.

So there we have, briefly, the potential of the minerals in the sea. Their use, as with everything else, depends today upon the capitalist economics of mining for profit and on international law and technology. In many cases the necessary equipment does not yet exist, although the knowledge of how it may be used does.


The above article is from the notes of a lecture given to our Birmingham Branch last year.

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