iiBSTRACT 



Yoimg pink salmon were less tolerant of tetrachlorocatechol 

 than were sockeye. Advanced sockeye alevins were more tolerant 

 of tetrachlorocatechol than were freshly hatched alevins, fry or 

 smolts. Sublethal concentrations of di- and tetrachlorocatechol 

 caused an increase in respiration rate which, it is believed, 

 indicated disruption of cellular processes by uncoupling oxidative 

 phosphorylation, Tetrachlorocatechol was apparentxy oxidized by 

 biological treatment with activated sludge and it was concluded 

 that all chlorinated catechols and phenols, except pentachlorophenol, 

 would be oxidized by this treatment, if present in bleach waste. 

 Toxic strengths of chlorinated catechols and phenols were between 

 those of the non-chlorinated molecules and a common insecticide. 

 Application of the results was discussed in light of the possible 

 synergistic effects resulting from a mixture of chlorinated organic 

 compoxinds and other toxicants of industrial and domestic origin. 



