RESPONSES OF ICHTHYOPLANKTON 

 TO STRESSES SIMULATING PASSAGE 

 THROUGH A POWER-PLANT 

 CONDENSER TUBE 



GERALD V. POJE, THOMAS C. GINN,* and JOSEPH M. O'CONNOR 

 New York University Medical Center, Institute of Environmental Medicine, 

 Tuxedo, New York 



ABSTRACT 



A power-plant condenser-tube simulator that can subject entrainable organisms 

 to temperature changes, pressure and flow variation, biocides, and fluid-induced 

 stresses similar to those at existing power-plant condenser tubes was designed 

 and constructed. Larvae of carp {Cypriiius carpio) and striped bass {Morone 

 saxatilis) were exposed for 5 min total duration to a range of entrainment 

 stresses in three experimental designs: (1) Temperature was varied while a flow 

 velocity of 1.22 m/sec and a minimum pressure of 0.51 atm was maintained; (2) 

 flow was varied, and a constant, sublethal temperature increase (AT = and 

 8.2 C for bass or 16.7 C for carp) was maintained; and (3) biocide concentra- 

 tions (sodium hypochlorite) were varied at constant velocity (1.22 m/sec) and 

 AT (0 and 8.3 C or 11.1 C). Carp larvae had significantly higher latent 

 mortalities at 18.1 C AT (36.1°C final temperature), and striped bass were most 

 sensitive at 15.5 C AT (33.6°C). A complicated survival pattern developed 

 because of the combined stresses. 



The past quarter century has seen a rapid prohferation of 

 steam-electric power plants using once-through cooling. Among the 

 stresses encountered by organisms entrained in the cooling-water 

 flow are thermal shock, turbulent flow and velocity-induced shear 

 forces, subatmospheric pressures, and variations in dissolved oxygen 

 concentrations (Coutant, 1970). In addition, many installations treat 

 cooling-water systems with biocides to defoul the surfaces of heat 

 exchangers (condenser tubes; Beauchamp, 1969). 



*Present Address: Tetra Tech, Inc., Lafayette, California. 



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