540 MOSS, BOONYARATPALIN, AND SHELTON 



23°C. Surface temperatures corresponding to the fish's location 

 varied between 27 and 32° C. The fish appears to have spent several 

 days downstream from the thermal discharge zone before beginning a 

 steady upstream movement on June 11, passing directly under the 

 thermal plume. The temperature profiles taken along the path of 

 movement indicated that his swimming depth was greater than 5 m. 

 Five hours and 20 minutes passed between the recordings of 

 positions 19 and 30. Horizontal movement of about 12 m/min 

 against an 18- to 36-m/min current was continuous between positions 

 20 and 27. The fish continued swimming steadily upstream until he 

 passed out of the study area (positions 28 to 30). The path and the 

 transmitted temperature suggest that the fish moved in the cooler 

 underflow of water in the river channel. 



Flathead Catfish 



A 3.8-kg male flathead catfish collected from Lay Reservoir was 

 implanted with a temperature transmitter on Aug. 26, 1974, and 

 released the next day about 550 meters downstream from the plant 

 in the river (Fig. 4). His movement was tracked for 7 days before 

 contact was lost. The surface temperature distribution depicted in 

 Fig. 2 was typical for the period. Positions 1 to 20 were recorded on 

 3 consecutive days after release. Transmitted temperatures were 

 between 28 and 30° C, and corresponding surface temperatures were 

 31 to 33°C. The relation between transmitted temperatures and river 

 temperature profiles indicated that the fish was maintaining a depth 

 of 1.5 to 3.0 m. Movement did not appear to have a particular 

 pattern but was rather general in a 0.8- to 1.2-km portion of the river. 

 However, 5 days later the fish was located 0.8 km upriver from the 

 plant, and the next day he was 1.5 km downstream, near the area of 

 release. Six days later (Sept. 10) the fish was again upstream from 

 the plant, and the next day he had moved more than 1.5 km 

 downstream. Despite the lack of continuous observations, we know 

 the fish moved past the thermal zone during the period of maximum 

 development at least four times in the 2-week tracking period. The 

 depth of movement suggests that the fish probably passed under the 

 thermal area, as did channel catfish no. 2. 



Largemouth Bass No. 8 



Largemouth bass no. 8 was captured Sept. 3 in Yellowleaf Creek 

 about 4 km upstream from the Coosa River. The fish, a 1.7-kg 

 female, was kept overnight in cooled water (18°C) after implantation 

 of a Bayshore Systems thermistor transmitter. The ambient water 



