Tolerance 



Relative capacity of an organism to endure or adapt to an unfavorable 

 environmental factor. 



Tombolo 



Ear or spit connecting an island or structure to the mainland or to 

 another island. 



Toxicant 



Substance that kills, injuries, or impairs an organism. 



Toxicity 



Quality, state, or degree of the harmful effect resulting from alteration 

 of an environmental factor. 



Training works 



Structure to direct current flow; see jetty. 



Trestle 



Braced framework of timbers, piles, or steelwork; see pier. 



Turbidity 



Deficient in clarity; muddiness, murkiness. 



Vertebrate 



Animal having an internal skeletel system. 



Walers 



Horizontal members attached to piles in bulkhead; see Figure 27. 



Wave runup 



The rush of water up a structure or beach en the breaking of a wave. 



Weep holes 



Drainage hole in a structure allowing release of groundwater to prevent 

 a buildup of water behind the structure. 



Weir jetty 



An updrift jetty with a low section or weir over which littoral drift 

 moves into a pre-dredged deposition basin which is periodically dredged. 



Wharf 



Structure built on shore so vessels may tie alongside. 



Zooplankton 



Planktonic animal life. 



156 ir US GOVERNMENT PRINTING OFFICE: 1980— 676-972 



