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penetrated areas of the ocean. 



They, too, must feed, often on each other, often on material that 

 is organic and that washes into the sea from the land. 



Consequently, the coastal, shallow waters of the ocean have the 

 highest production of the material that forms the base of the food chain. 



Upon this plankton feed small organisms, small fish, and so on, each 

 predatory species requiring a certain volume of prey for survival. 



Thus, the higher one rises on the food chain, the larger the in- 

 dividuals of the species. The total weight of the species, however, is 

 less than that of the prey, primarily because all the weight of the prey 

 is not converted into predator but is consumed through activity and 

 then discharged. 



Larger fish tend to grow slower and live longer. This food chain 

 system operates in a fluid environment. Movements of marine water will 

 have impacts on availability of food. So will the temperature of that 

 water, the amount of light available, and the presence of prey. 



The marine environment's conditions depend, in large degree, upon 

 the following variables: 



• Rotation of the earth (night and day) 



• Currents - these are partly driven by the effects of rotation; 

 Coriolis effect 



• Season of the year 



Latitude and longitude 



• Temperature of the waters 



• Topography of the bottom 



• Surface weather effects, both short-term and long-term 



