151 



Contaminant studies .- Dioxxns, furans, and related compounds should be studied 

 for both their extent in the Grays Harbor environment and benthic organisms, 

 and their effects on aalmonid prey organisms. The links between the 

 contaminants, the prey organisms, and the salmonids Bhould also be studied. 



Feasibility of oyster larvae bioassavs .- Studies to evaluate effluent 

 bioassays on oyster larvae should be completed. If feasible, the bioasaays 

 should be required on at least a quarterly basis for continued NPDES licensing 

 of pulp mills. 



Potential Additional Information HeedB 



It coded-wire tagging studies indicate salmon survival has not improved, the 

 following studies should be conducted. 



Parasite/contaminant studies .- The combined effects of paraBtism by 

 NanophyetuB (a liver fluke) and/or Ceratomyxa (a myxosporidian known to cause 

 aalmonid mortalities) and exposure to various pulp mill effluents on coho 

 smoltif ication should be investigated (Schroder and Fresh 1992). 



Further effluent toxicity tests .- Although waste treatment at both Grays 

 Harbor pulp mills has been upgraded, the new effluent has not been retested 

 for toxicity to salmonids. One argument is that fish are less likely to be 

 killed by dioxins as a group now than before, because dioxins produced in 

 oxygen bleaching are below detection limits. The rebuttal is that detection 

 limits may be greater than the highest safe dose for long-term fish survival. 

 Detection limits are set by equipment capability, technique, precision, and 

 cost. There is a chance that although total dioxins are reduced, TCOD, the 

 more toxic of the 135 forms of dioxin, may be more abundant now than before 

 (Malek, EPA, pers. comm. ) . It is also possible that a synergistic effect of a 

 variety of contaminants could be affecting salmonids; toxicity tests similar 

 to those reported by Schroder and Fresh (1992) should be conducted for all 

 salmonid species if tagging does not indicate improved survival. 



Sediment as a contaminant reservoir .- If sediments serve as a reservoir of 

 contaminants that are killing fish, then cleanup of mill waste may not 

 immediately resolve the problem, and the need would arise for a more 

 comprehensive picture of the distribution of the most toxic substances as body 

 burden in salmon prey organisms. 



Long-term survival of contaminated fish .- If contaminant analysis shows 

 tainted juvenile salmon in the inner Harbor and clean fish in North Bay, fish 

 might be captured from each area and held for a number of months in 

 uncontaminated .saltwater, with mortality and condition at death observed. 

 This experiment would differ from previous studies (Schroder and Fresh 1992) 

 on long-term survival in that the experimental groups of fish would be assumed 

 to have eaten contaminated or clean prey, respectively. 



