S-4 



SPORT FISH 



(Game Fish) 



SPRING OVERTURN 



A physical phenomenon that may take place 

 in a body of water during the early spring. 

 The sequence of events leading to spring 

 overturn include: (1) melting of ice cover, 

 (2) warming of surface waters, (3) density 

 changes in surface waters producing convection 

 currents from top to bottom, (A) circulation 

 of the total water volume by wind action, and 

 (5) vertical temperature equality. The 

 overturn results in a uniformity of the 

 physical and chemical properties of the entire 

 water mass. (See Fall Overturn, Overturn) 



SPRING TIDE 



Exceptionally high tide which occurs twice 

 per lunar month when there is a new or full 

 moon, and the earth, sun, and moon are in a 

 straight line. (See Neap Tides ) 



STANDARD 



STANDING CROP 



STENO- 



( Water Quality Standard ) 



The quantity of living organisms present in 

 an environment at a selected point in time. 



Prefix denoting a narrow range of tolerance 

 of an organism to a specific environmental 

 factor; e.g., stenothermal refers to temperature; 

 stenohaline refers to salienity; etc. (See Eury-) 



STIMULUS 



An influence that causes a response in an 

 organism. (See Taxis ) 



