110 



Poor Siolt Survival in the E»tuary 



WDF coordinated a aeries of studies of inner Harbor pollution on salmon. 

 Primary findings included (Schroder and Fresh 1992): 



- Inner Harbor fish were more highly stressed and less able to resist 

 disease than fish from North Bay; 



- smolts move in and out with the tide and rest in low-velocity areas, 

 i.e., coho spend considerable time in areas most likely to be polluted; 



- Inner Harbor fish showed four times the mortality of North Bay fish 

 during long-term observation; 



- in the short term, full-strength Weyerhaeuser effluent was 

 intermittently lethal to coho amolts; 



- over the long-term, liver enzymes involved in the metabolism of 

 toxicants and other foreign compounds increased in fish exposed to 

 dilutions of Weyerhaeuser effluent at 30 percent and higher; 



- swimming 8ti-;,~r.;. was reduced when smolts were forced to swim in effluent 

 solutions from either mill; 



- in lab experiments, coho usually avoided low concentrations of 

 Weyerhaeuser effluent, but failed to avoid any odors after exposure to 

 ITT effluent. 



In a variety of other tests over recent years, effluent from both plants was 

 variously lethal or toxic to a variety of non-salmonid tests organisms (WDF 

 1971; WDE 1975; Hallinan 1989; Reif 1989a, b; Johnson et al. 1990; Schroder and 

 Fresh 1992) . 



Toxic Chemical* in Mill Effluent 



Studies reviewed and/or conducted by Reif (1989b), Johnson et *1. (1990) and 

 Schroder and Fresh (1992) analyzed effluent of both mills for metals and a 

 variety of organic compounds including herbicides, pesticides, guaiacols, 

 catechols, dioxins, furans, cadmium, copper, lead, nickel, zinc, chloroform, 

 4-methylphenol, and resin acids. 



Schroder and Fresh (1992) stated that, at 30 percent dilution, all potential 

 toxins in the effluent would fall below detection limits. This suggested that 

 unidentified constituents of the effluent affected mortality. Over 4,000 

 chlorinated organic chemicals may occur in pulp mill effluent, but the effects 

 on fish are known only for a few of them. They hypothesized that the bioassay 

 organisms were responding to either (1) different chemicals than the ones that 

 could be analyzed in correlation, (2) lower concentrations of chemicals than 

 previously reported to be toxic or (3) other toxicants not analyzed. 



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