Figure 8. A simplified energy flow model typical of an estuarine system. 





y^^.^ ^y ""---.rfs 



Trophic level 4 

 Trophic level 3 

 Trophic level 2 



Trophic level 1 



ih. 



INCIDENT LIGHT ENERGY 



Top carnivore! 

 Carnivores 



Herbivores 



'ENERGY 

 LOST 

 AT 

 , EACH 

 Photosynlhetic \ LEVEL 

 plants, primary 

 producers 



Figure 9. Conceptual model of the hydrologic 

 cycle (adapted from Caswell 19/7). Elements and 

 inuriianic compounds, many of which are essential 

 components for the biolta, circulate through the 

 biosphere dissolved in waters. 



Figure JO. Simple trophic pyramid of energy 

 (Odum J 971). 



52 



