SECTION ONE 



CHAPTER /J 



ZONES OF THE SEA— Where They Live 



The study of mankind— his behavior, his diseases, his. history— could not progress 

 very far nor be very meaningful if careful attention vere not paid to his 

 environment— where he grew up and under what circumstances, the climate, 

 culture, geographical location, and economic conditions. The same is true of 

 wild life. Whatever aspect we care to study, scientific or aesthetic, a considera- 

 tion of the environment must enter our minds. If one tries to imagine a plant 

 or animal without environment, it becomes almost impossible to obtain much 

 insight into its nature, whether it be a one-celled animal or a complex animal 

 such as man. For instance, the odd shape of a sargassum fish has little meaning 

 by itself, but when it is viewed from the perspective of self-preservation in its 

 habitat of sargasso weed, its meaning as a concealing, protective form becomes 

 clear. 



The study of the relationship between life and its environment is scientific 

 natural history or ecology. Ecology might be called the crossroads of the life 

 sciences, where such fields as genetics, paleontology, anatomy, physiology, 

 embryology, animal behavior, oceanography, evolutionary study, and others find 

 common ground. But let none assume that ecology is for the scientist only. The 

 diver who has learned to associate groupers with their homes in coral or rock 

 has made an ecological observation. 



Ecology is the subject of the first two chapters of this book in the hope that 

 as insight into the sea's environment increases, so will our ability to appreciate 

 the beauties and wonders of tfte sea increase. In this chapter the main character- 

 istics of the sea and its zones will be given. The ways and means that life has 

 adapted to this environment will be discussed in the chapter which follows. 



EARTH AND THE SEA 



The perspectives and visions of mankind are often not as broad as we would 

 like to believe. Much of the narrowness of man's particular world is a con- 

 sequence of the evolutionary place he has come to occupy— that of a giant land 



