A VAST POPULATION

Hokitika Guardian, 30 November 1928, Page 7

A VAST POPULATION

TEEMING LIFE OF THE SEA

‘‘ll i.s strange to think how limited is one’s knowledge of the sea, which covers the greater part of this world of ours, and forms, for ns islanders, a so lamiliar and significant portion of oui environment. What does the landsman know of it?” asks Dr R, Lloyd I’raojer in the Cornhill Magazine. The sea contains a vast population beside which that of the land sinks into insigm li ance; but where is the food supply of these countless hordes? Seaweeds in abundance there arc, clothing the rocks between tides, and extending downwards to a certain depth; but this depth i.s negligble. Seawiceds, like land plants, must have light; and light becomes very dim under a few fathoms of water; in consequence, the seaweeds that we know form the merest narrow fringe round the edge of the land, whereas the ocean is populous with creatures from shore to shore, and from the surface down to miles of depth. The miseroscope reveals the clue to this mystery. “Every drop of .sea water taken at or near the surface is hound to be crowded with very minute plants known as diatoms. In countless millions they swarm and propagate from the Pole to the Equator, absorbing solar energy, and Using it to. build up the complicated chemical substances which form their bodies. Countless millions of minute animals find in these miscroscopic plants their food supply breaking down in the course of digestion the materials of the plant-body, and utilising the energy thus set free for the purposes of their own lives. On these microscopic animals form, in turn, larger sea beasts pre.v, and so on, it may be through a chain of many links, till we reach the giants of the ocean. On land the similar chain of food supply is interwoven across the surface only, or very close to it. In the sea it originates on the surface, but it is by no means confined thereto, its links spread downward into the profoundest depths, sometimes in the form of living animals, often as dead matter, sinking slowly to provide nourishment for the hungry creatures of the middle waters and of the distant ocean floor.

“So it comes about that the life of the depths owes its existence and continuance wholly to that sun which, to the creatures living under that black pall of water, might be deemed as ineffective as the farthest star. “The abundance of this minute life in the ocean not only in the surface waters, but far down into the depths, staggers the imagination. A single cupful of water may contain, according to place and season, tens of thousands or hundreds of thousands ot minute plants and animals. No fess astonishing is their power of propagation, against which one must set their wholesale destruction at the hands of the creatures that prey upon them. An ordinary marine bacterium will, in the course of a week or two under normal circumstances multiply to the extent of several millions. On the other side we fil’d that the stomach of a single sardine has been estimated to contain 20 millions of ceratium, otic of the cominoner infusoria, to whose presence’ phosphorescence in the sea is frequently due. “I!ui large figures convey a- pool idea of actual numbers, when they pass beyond thousands it matters little whether they be millions or billions; the mind cannot envis-ge them. Suffice it to say that life in-the sea, especially hut not, only, among the smaller organism, its profusion its fecundity, and the destruction to which it i.s subject, ir on a scale which beggars imagination.”