It is not ]X)ssibIe liere to describe tlie fauna found 

 in the various regions and subregions nor to analyze 

 the interesting paleo-ecological history of each re- 

 gion. In general the Indo-ll'cst Pacific rcyion and 

 specifically the Indo-Malayan subregion have the 

 greatest abundance, variety, and distinctness of ani- 

 mal life. This is expressed in many different taxo- 

 nomic groups with significant percentages of fam- 

 ilies, genera, and species being exclusive to the region 

 or subregion. This may represent the ancient pro- 

 fusion of forms that during the early Tertiary ex- 

 tended more or less around the world. This ancient 

 fauna persisted here because the region was not sub- 

 jected to the cooling of the climate and waters that 

 occurred elsewhere during late Tertiary and the 

 Quaternary and which brought impoverishment of 

 the fauna. 



The West Indian subregion of the Atlanto-East 

 Pacific region ranks next to the Indo-Malayan sub- 

 region in size and richness of fauna. The shelf fauna 

 of the .Worth Pacific region and adjacent Polar- 

 .■\rctic, especially on the American side of the Pacific 

 Ocean, is much richer than that of the North Atlantic 

 region. Both the Arctic and Antarctic regions have 

 a number of endemic forms, but in general the Ant- 

 arctic fauna, especially of invertebrates, is much 

 richer in species. There are a few species of crabs. 

 Cancer, a starfish, Ctendisciis crisf'atiis. and some 

 other organisms that occur in both polar regions 

 with continuous intermediate distribution. However, 

 the species occur in shallow waters in the polar re- 

 gions and only in the deeper cooler waters of the 

 tropics. Various other species or related forms are 

 found in the two opposite polar or temperate regions 

 only, with presumably the interconnecting tropical 

 linkage having become broken sometime during past 

 geological time. 



APPLIED ECOLOGY 



Although 71 per cent of the earth's sur- 

 face is occupied by oceans and only 29 per cent by 

 land, nearly all of the food and raw materials used by 

 man is derived from the latter. This is in spite of the 

 fact that agricultural soil is only a few inches thick 

 and must be cultivated, protected from erosion, and 

 fertilized, while the ocean with its chemical fertility, 

 its photosynthetic production of basic plant food, and 

 its fisheries appears almost inexhaustible. 



Because of its high productivity, the plankton of 

 the sea represents an important potential food supply 

 for man (Davis 1955). Its energy value is approxi- 

 mately 4 Cal/g dry weight, and it is more or less 

 palatable (Clarke and Bishop 1948). However, there 

 are difficulties involved in securing significant 

 amounts, poisonous species sometimes occur, it is not 



easily digested and assimilated, antl consecjuently it 

 has not as yet proved to be a feasible diet. The energy 

 value of the plankton is used by man at the present 

 time primarily as it is transferred into higher links 

 of the food chain. Aside from the fishes, the chief 

 marine organisms used as food are the oysters and 

 other mollusks, shrimp, crabs, lobsters, and sea tur- 

 tles. These are mostly animals of the continental shelf 

 and estuaries. 



There are a number of ])roblems in the use and 

 conservation of marine organisms. Natural beds of 

 .American oysters on the Atlantic coast have nearly 

 all been exhausted through over-fishing and pollu- 

 tion. Becau.se of heavy erosion of the land, silt depo- 

 sition has become excessive in most of the bays and 

 estuaries and there is increasing difficulty for oyster 

 spat to find clean hard surfaces on which to set. Sur- 

 faces that are loose or covered with silt are not suita- 

 ble since the spat is very small and easily smothered. 

 A common practice is to return to suitable areas all 

 shells of mollusks removed or to introduce other 

 suitable hard objects to furnish the necessary sub- 

 stratum for oyster setting. Control of erosion over 

 the watershed would greatly alleviate the problem. 

 The trend is increasing to lease suitable areas of 

 water and to farm oysters in the manner of an agri- 

 cultural crop (Korringa 1952). 



In spite of their position at or near the top of the 

 food chain, the greatest utilizable food resource of 

 the sea is its fin fishes. The service of transferring 

 the basic fertility of the sea through successive stages 

 in the food cycle to fishes is performed by nature, and 

 man needs only to harvest the final crop. The great 

 bulk of commercial fish is in the families of herrings, 

 codfish, salmons, flounders, and mackerels. Probably 

 most kinds of fish are potentially useful, although 

 some species that occur in coral reefs are inedible 

 or poisonous. Tunas were not widely eaten in the 

 United States until 1928; swordfish, once anathema 

 to fishermen, are now as expensive as steak. Sharks 

 were not used until a few years ago, but are now a 

 major source of vitamins. The loss of elements from 

 the ecosystem with the removal of fish is replaced 

 by the continued inflow of nutrients from the land by 

 way of the rivers. A fishery, temporarily exhausted, 

 will usually become replenished by natural processes 

 if left alone for a period of time. When one realizes 

 that with the same expenditure of effort a man in a 

 year's time can harvest two and one-half times as 

 much edible fish as he can pork in pigs, it would 

 appear that the ocean community is one that should 

 be more extensively utilized (Taylor 1951, Walford 

 1958). 



The situation is different with whales and seals. 

 Whales have been pursued so vigorously for their oils 

 that certain species are in danger of extinction. Seals 

 have been taken extensively for their fur. Interna- 



Marine biomes 371 



