RESPONSES OF ICHTHYOPLANKTON 



799 



1.0 2.0 3.0 4.0 5.0 



FLOW-THROUGH CONDENSER TUBE, m/sec 



6.0 



Fig. 2 Pressure at the inlet to the condenser tube vs. flow velocity 

 at three elevations above the simulator skid. 



exposed to the biocide concentrations and thermal stresses applied to 

 the condenser loop. Neither the fluid-induced stresses of condenser 

 passage nor the stress of net collection was experienced by barrel 

 controls. Flow controls were used in experiments where flow and 

 temperature were the variables examined. These consisted of 30 

 organisms poured into each collection net and held for a 5-min 

 exposure. The stresses encountered included the thermal changes in 

 the condenser loop and the mechanical damage of net collection but 

 not the fluid-induced damage of condenser passage. 



After the 5-min exposure period, all organisms were rinsed in 

 quarry water and returned immediately to ambient conditions. All 

 test groups were held at ambient temperature in flow-through 

 containers equipped with individual quarry water supphes. Satura- 

 tion of dissolved oxygen did not fall below 90% in the source-tank 

 (intake) and collection-tank (discharge) water. Mortalities were 

 determined immediately after exposure, and latent effects were 

 observed at 24 and 48 hr. 



Both species were subjected to a range of exposures for each 

 variable examined (Table 1). For temperature experiments the lethal 

 hmits of exposure regimes and AT for each species were the 

 objectives. For flow and biocide experiments, we assumed that the 



