CHAPTER TWENTY-FIVE
NEED FOR PROTECTION OF CREATURES THAT LIVE IN THE WATER
Perhaps you think it is absurd to talk about caring for the creatures that live in the water, since they can so easily hide away in its depths where we cannot follow. Perhaps you think that because the ocean is so great it would be impossible ever to catch all the fish that live in it. It is easy to understand how all the fish might be caught out of the creeks, rivers, and shallow lakes, since fish are hungry and we put before them such attractive bait; but with the ocean it seems different. It stretches so many thousands of miles and is so very deep that there does not appear to be any danger of exterminating the animals of the ocean as we have some of those of the land.
Is it true, however, that all the vast waters of the ocean are full of fish, or are they found only in certain parts? The fishermen can tell us about this matter. They know where to set the hooks and nets, and where they are most likely to get a good catch. They do not go far out where the water is deep but seek, instead, the shallow waters near the shore or about the reefs and islands. They know that the deep water of the ocean contains very few fish and none that are of any value as food.
Each kind of fish has become adapted to certain parts of the ocean, for both the food supply and the pressure of the water differ with different depths. Fish caught in deep water are often dead before reaching the surface, because of the decrease in the water pressure.
One reason why fish are not numerous far out in the ocean is because there is little food to be had there. The reason no fish are found in the very deep parts of the ocean is because the water there contains no air particles. Strange as it may seem, although fish breathe water, they cannot live unless it contains oxygen from the air.
The fish, then, that interest us because of their value for food, are found only in the shallow waters usually near the shore and in the lakes and rivers. Because of this fact it is possible, as we have learned from experience, to set so many traps and use so many nets and hooks as entirely to destroy certain species.
The fish have their natural enemies, and there is warfare among them just as there is among the land animals. The larger and more powerful live upon the smaller ones, but, seemingly to make up for this, Nature has given the small fish quickness of movement—which the large fish do not possess—to aid them in escaping. They have also the power of increasing very rapidly. The little herring, which is the chief food of many of the large fish, maintains its countless numbers against all its enemies except the fishermen.
The Indians, with their crude traps, hooks, and spears, could obtain but few fish at a time and did not reduce their numbers. But civilized man, with his cunningly contrived hooks and nets, has the same advantage over the fish that the hunter, with his repeating gun, has over the land animals. Nature, not foreseeing how destructive man would be, has armed neither the creatures of the land nor the creatures of the water against him.
