RESPONSES OF ICHTHYOPLANKTON 



803 



temperature and low flows (0.61 and 1.22 m/sec), simulator-run 

 groups had mean mortalities of 39.7 and 37.2% above the ambient- 

 exposed static group (32.7% mortality), and flow controls had 

 mean increases in mortality of 24.3 and 28.7% above the static 

 group [Fig, 4(a)] . There were no significant differences between the 

 two groups. At 11.1°C AT, mean mortalities of simulator runs at 

 0.61 £ind 1.22 m/sec were 43.2 and 44.2%, respectively; mean 

 flow-control mortalities were 3.8 and 14.1% above the thermal- 

 exposed static controls (44.3% mortality) [Fig. 4(b)]. Survivals for 

 the two test regimes were compared at the same velocity by 

 Student's t-test. At 0.61 m/sec the difference was significant 

 (P < 0.025) and at 1.22, P < 0.067. 



When flow velocities increased to 1.83 m/sec, the mortality 

 caused only by the collection net increased beyond simulator- 

 induced mortality with or without AT [Figs. 4(a) and 4(b)] . 



Carp had 100% survival at 48 hr under all test regimes with a 

 flow velocity of 0.61 m/sec and at either ambient (18.3°C) or 

 16.7° C-AT (35.0°C) exposure (Table 2). Increasing flow velocity to 

 1.22 m/sec resulted in a maximum mortality of 5.2%. At a velocity 

 of 1.83 m/sec and 16.7°C AT, simulator-run and flow-control groups 

 had mortality of 22.0% at 48 hr. 



TABLE 2 



SURVIVAL OF CARP LARVAE AFTER EXPOSURE TO THREE 

 CONDENSER FLOW VELOCITIES 



