The major oceans (Atlantic, pacific, Indian, arctic, and antarctic) and their connectors and extensions cover approximately 70% of the earth’s surface physical factors dominate life in the ocean. Waves, tides, currents, salinities, temperatures, pressures, and light intensities largely determine the makeup of biological communities that, In turn, have considerable influence on the composition of bottom sediments and gases in solution. The food chains of the sea begin with the smallest know autographs and end with the largest of animals (giant fish, squid, and whales). The study of the physics, chemistry, geology, and biology of the sea are combined into a sort of ‘’super science’’ called oceanography, which is becoming increasingly important as an international force. Although exploration of the sea is not quite as expensive as exploration of outer space, a considerable outlay of ships, shore laboratories, equipment, and specialists are needed. Most research is of necessity carried out by a relatively few large institutions backed by government subsidies, mostly from the affluent nations.

         To fully appreciate both the promise and the problems involved in man’s use of the sea we need to look at the contour of the sea bottom which also gives standard oceanographic nomenclature for zones of the sea. According to the now widely accepted ‘’continental drift theory,’’ some of the continents, especially Africa and south America as one pair and Europe and north America as another, were once quite close together and have drifted apart through the ages. The mid – Atlantic ridge is , according to this theory, the line of former contact between continents now hundreds of miles apart. As a citizen you will be hearing a lot about the continental shelf, that sloping plateau that borders the continents. Located here are the bulk of undersea oil and mineral wealth. From the edge of the shelf, which varies greatly in width from location to location, the continental slope drops off rapidly into the true of the sea. The topography of the continental slope is very rugged with huge canyons and ridges that are constantly changing under the forces of volcanic action and underwater ‘’landslides’’

         Since there are likely to be phytoplankton under every square meter and since life in some form extends to the greatest depths, the seas are the largest and ‘’thickest’’ of ecosystems. They are also biologically the most diverse. Marine organisms exhibit an incredible array of adaptations, ranging from flotation devices that keep the tiny planters within the upper layers of water, to the huge mouths and stomachs of deep sea fish that live in a dark, cold world where meals are bulky but few and far between. As shown in this post the continental shelf areas are fairly productive, seafood harvested here is an important source of protein and minerals for man. The most productive areas and largest fisheries are those that benefit from nutrients carried up by upwelling currents, a form of energy subsidy. Strong upwelling occurs in certain areas along the west coasts of the several continents. The Peruvian upwelling region, one of the most productive natural areas in the world, was singled out for special discussion on this post. The vast stretches of the deep sea, however, are mostly semi desert with considerable total energy flow. (because f the large area) but not much per unit of area. The autotrophic layer (phonic zone) is so small in comparison with the tropospheric layer that the nutrient supply in the former is limiting. A number of schemes have been proposed, and there are now several experiments under way, to tap the potential energy of vertical temperature differences to create artificial upwelling. Even if man is not able to obtain much food from the deep – sea area it is nevertheless very important to him, for the seas act as a giant regulator that helps to moderate land climates and maintain favorable concentrations of carbon dioxide and oxygen in the atmosphere.

       International conferences are now being scheduled to discuss the thorny problem of setting up international law with rules and regulations for exploiting seabed minerals and energy resources. Since, as we have noted, most mineral wealth, as well as most exploitable food, is located near shore, it would seem reasonable for each country to assume stewardship of the shelf area adjacent to its land territory, but the large differences in width of the shelf make such a simple solution difficult, perhaps impractical. Most objective assessments (see, for example, cloud,1969) warn against undue optimism that the deep sea is a vast storehouse just waiting to be exploited. Recovering such resources as there are will be even more expensive than getting minerals and oil from the shelf where costs are indeed huge. Remember that sea is more important as a life support and climate regulator than it is as a supply depot. Anything we do to exploit the latter must not jeopardize the former (recall our point about ‘’gross and net’’energy).

       For the most part in this website we have based our approach to ecology on the analysis of units of the landscape as ecological systems. Principles and common denominators that apply to any and all situations, whether aquatic or terrestrial, natural or man – made, have been emphasized. The importance of the driving force of energy has been stressed. In this post useful approach was introduced, that of concentrating study on population units which are the vehicles for evolutionary change. Still another useful approach is geographical – involving the study of the pattern of earth forms, climates, and biotic communities that make up the biosphere. In this post we shall list and briefly characterize the major ecological formations, or easily recognized ecosystem types, with emphasis on geographical and biological differences that underlie the remarkable diversity of life on earth. In this manner we hope to establish a global frame of reference for the next and this post, which deals with mankind’s new challenge to attack his problems on a large scale.

       We would do well to start our world tour with the seas, the largest and most stable ecosystem. The sea, presumably, was the first ecosystem, for life is now thought to have originated in the saltwater nileu.

       The energy resource situation in the united states, as well as in all of the other industrialized nations and most of the undeveloped ones can be very simply and bluntly stated as follows; energy use is, or will very soon be, greater than that which can be supplied at a reasonable cost form source within the boundaries of the nation. Which is to say that even where there are large reserves such as coal, oil shale, or offshore oil, the high cost of procurement and conversion will place severe constraints on economic growth and create difficult balance of trade problems for individual nations. Undeveloped countries that lack fuel resources ae particularly hard hit when the rice of fuel rises. The need to conserve energy (by reducing waste and increasing the efficiency of use), to allocate supplies on a worldwide basis, to increase efficiency of conversion of ‘’difficult to get at’’ sources, and to seek new sources will all receive the undivided attention of mankind for a long time into the future. This is a prime example of the long range problem that cannot be solved on a crisis basis.

         It is vitally important that everyone study carefully and strive to understand the nature of atomic energy, about which there is so much hope and controversy. It is especially important to distinguish between to several types of nuclear power. The kind of atomic energy now being used to generate electricity on a limited scale is based on the fission or ‘’splitting’’ of the uranium with the release of energy, and also the release of dangerous ‘’fission products’’ such as radioactive strontium and cesium. Some plutonium, an extremely dangerous radioactive substance (and, also, one that can be made into bombs), is also a by product. Fission atomic energy is a ‘’fuel’’ energy since the supply of fissionable uranium (²³⁵U) is limited); actually there is less energy in this form than in coal left in the earth’s crust. Also, tapping this source of energy is proving to be more troublesome and expensive than originally predicted. The breeder reactor now undergoing experimental test would rolong the uranium fuel supply since a more abundant from of uranium (²³⁵U) can be used and new fissionable fuel is created in the reactor as the original fuel is used up. But an increased production of plutonium increases the radiation hazard.

         Nuclear fusion is a different form of atomic energy entirely, one that involves the fusion of light atoms such as hydrogen to form a heavier atom with the release of energy. Extremely high temperatures are necessary for this energy release which resembles that which occurs on the sun. fission products and plutonium would not be produced unless a fission reaction were to create the temperatures necessary for fusion (as in the hydrogen bomb), but there would be problems with radioactive hydrogen (tritium). Controlling fusion involves containing the intense reaction, perhaps within magnetic fluxes or with laser beams, since no vessel could stand the temperature required. There is much discussion about hybrid fission – fusion systems, but any widespread use of fusion as a worldwide source of industrial energy is a long way in the future. Recent issues (1972, 1973, and so on) of science and public affairs: bulletin of the atomic scientists contain many informative and largely nontechnical articles on nuclear energy. For a nontechnical book, see Inglis (1973).

        We have already discussed in some detail solar energy (see this post). This abundant, but dilute and low quality energy resource can be put to work in cities doing low level ‘’jobs’’ such as heating water, commercial buildings, and dwellings thus sparing fuel for other uses. Extensive use of solar energy in the place of fuel requires a technology not yet developed. Direct conversion of sunlight into electricity by means of solar cells is a promising new technology now under intensive study. Another way we could upgrade solar energy for higher level work would be to make use of nature’s efficient conversion, namely photosynthesis, for fuel as well as for food. Szego (1973) has calculated that the annual growth of wood in managed ‘’fuel forests’’ could supply the united states with substantial amounts of electricity if burned in wood fired, steam electric plants. The long term cost benefit of such a use is yet to be calculated but it is a possibility worth considering in regions where forests are climax, human population density low, or where there is a lot of hilly land not suitable for agriculture

or other man forest uses.

         The ‘’food for man’’situation was discussed in detail in this post reemphasizes the key role that energy subsidies play in the production of food and fiber (cotton, wool, paper, wood, and so on). The age old paddy rice culture is very efficient in terms of food yield per unit of energy subsidy, but it is backbreaking for the people who plant and harvest the rice. At the other extreme, feedlot beef requires 10 cal of fuel energy for every calorie of food produced, but neither man nor beast has to do much work. Feedlots do not make very good ecological sense for another reason. Cows have a marvelous adaptation the rumen, which enables them to convert very low protein food such as grass and hay into high protein food. When cows are fed rich grains in a feedlot, this adaptation is bypassed, and the meat produced tends to be too fatty for good human health. Also, feedlots produce server watershed pollution that adds another stress on the environment, and another cost for man. There is much to be said for putting the cow back on grass.

        Avoidance of the boom and bust syndrome, as discussed on this post is another reason for considering a somewhat Les energy intensive agriculture especially for undeveloped countries. It is difficult and costly in terms of energy to sustain very high yields of the same crop over long periods of time.