minutes in a concentration of 0.5 ppm and up to 



1 hour and 49 minutes in 1 ppm . One hogsucker 

 survived an exposure of 3 hours and 15 minutes 

 in a 0.5 ppm concentration and recovered fully 

 when it was returned to a livecar . 



None of the fish except shiners and 

 darters had an average time of death of less 

 than 1 hour when exposed to 0.5 ppm of toxicant. 

 Smallmouth bass and rock bass were killed in 1 

 hour or less when concentrations were 1 or 

 more ppm . 



The wide range of responses exhibited 

 among the small numbers of specimens of each 

 species indicated that both the minimal effective 

 concentrations of toxicant and the durations of 

 exposure necessary in a stream might be greater 

 than the tests showed. It was decided that a 

 concentration of at least 1 ppm would be adequate 

 in Abrams Creek if it were maintained for a 

 minimum of 6 hours in an uninterrupted bolt. 

 On the basis of the salt-resistivity tests on 

 Abrams, it appeared that the desired bolt of 

 toxicant could be established best by applying 

 the Pro-noxfish at a rate of 5 ppm for the first 

 hour and at the rate of 1 ppm for 5 hours there- 

 after. 



The wide range of results in the toxicity 

 trials also indicated the need for additional tests 

 with larger numbers and more species of fish . 

 There was no opportunity to do so prior to the 

 reclamation of Abrams, but it was apparent 

 that such data would be of value in planning the 

 reclamation of other streams . Tests were 

 made, therefore, with 461 fish of 24 species in 



2 trout -rearing pools on Anthony Creek, a 

 major tributary of Abrams Creek. The results 

 are included here since they are pertinent to the 

 problems of stream reclamation (table 2) . 



The concrete rearing pools are 50 feet 

 long and have individual sources of water from 

 Anthony Creek . The water is clear, slightly 

 acid, and very soft. Its resistivity averages 

 96, 300 ohms (at 77° F.) and its estimated total 

 of dissolved solids is 14.5 ppm . Most of the 

 test fishes were collected in park streams. 

 Some of the trout were obtained from a Federal 

 fish -cultural station and some of the carp, the 

 goldfish, and catfish were furnished by the 

 Tennessee Game and Fish Commission from 

 collections made in TVA lakes. 



Eighteen species of fish were killed 

 within 6.5 hours when they were exposed to 0.5- 

 and 1-ppm concentrations of Pro-noxfish at 56 to 

 66° F . Trout were the first to die and sunfish 

 the last. Some of the carp and bullheads, and 

 all of the goldfish survived the tests . They were 

 kept under observation for several days in fresh 

 water and they appeared to suffer no lasting 

 effects from the rotenone. 



Better results were obtained in tests in 

 which the concentration of toxicant was 5 ppm 

 for the first hour and 1 ppm for 5 hours there- 

 after. Fourteen species, including carp were 

 exposed at temperatures of 63 to 65° F. and all 

 specimens died within 5.3 hours. 



The influence of low temperatures on 

 reducing the effectiveness of rotenone was ob- 

 served in several trials. In cool water (48-52° 

 F.), some fish, including goldfish, blue catfish, 

 and brown bullhead, survived 22.6 hour expo- 

 sures to 1 ppm of Pro-noxfish. At 40°, some 

 of the stoneroUers and blue catfish, and all of 

 the carp and goldfish survived 5. 5 -hour expo- 

 sures to 2 ppm of the toxicant. Indeed, gold- 

 fish were exposed to the 2 -ppm concentration 

 for 77 hours at 40° but they neither turned over 

 nor died. Four goldfish also survived a 6.5- 

 hour exposure to 4 ppm of a Chem-fish Special, 

 5 -percent rotenone formulation at 49° . 



The only test in which any goldfish were 

 killed was made with 8 ppm of Pro-noxfish at 

 67° F. The carp and blue catfish included in the 

 test were dead within 3 hours . Five of the gold- 

 fish died after an exposure of 5.75 hours, but 

 one fish survived. 



The necessity for considering the species 

 of fish present and the water temperature in the 

 reclamation of a stream was clearly demon- 

 strated by the toxicity tests . It was concluded that 

 23 of the 24 species of fish tested could be killed 

 in a stream if: 1) the toxicant were applied at 

 5 ppm for the first hour and 1 ppm for 5 hours 

 thereafter, and 2) the water temperatures were 

 60° F. or higher. The goldfish is the significant 

 exception and the results of the tests indicate 

 that it would be very difficult to eradicate gold- 

 fish in a stream with rotenone. 



