All of the classes of PAHs were considerably elevated in concentration in the samples that were highly 

 toxic to microbial bioluminescence (Table 27). The average concentration of LPAH in the highly toxic 

 samples exceeded the average concentration in the nontoxic samples by a factor of 25.6 and exceeded 

 the ERM value by a factor of 18.9. Also, the concentrations of petroleum-related compounds, 

 acenaphthene, and phenanthrene were very high in the highly toxic samples. All three of the individual 

 PAHs exceeded the proposed National SQCs (U.S. EPA, 1994) in the highly toxic samples. The con- 

 centrations of organic carbon, inorganic carbon, and fine-grained sediments were slightly higher in the 

 highly toxic samples relative to the nontoxic samples. 



Relationships between Toxicity and Physical-Chemical Parameters: Phase 2. The Spearman-rank 

 correlations between amphipod survival in the Phase 2 samples and the concentrations of trace metals 

 are compared in Table 28. The correlations were performed for the concentrations of total individual 

 metals, total acid-volatile sulfides (AVS), and the SEM/AVS ratios. The correlations between percent 

 amphipod survival and total metals concentrations were significant for all elements except arsenic, 

 aluminum, iron, nickel, and antimony. The concentrations of total cadmium were most strongly corre- 

 lated with amphipod survival. Also, amphipod survival was significantly correlated with increasing 

 concentrations of AVS. However, the ratios of total SEM to total AVS were not correlated with amphi- 

 pod survival. If the number of variables (16) were taken into account, only correlations listed as "**" 

 would remain significant. 



Table 28. Spearman-rank correlations (Rho, corrected for ties) between percent amphipod sur- 

 vival and the concentrations of total trace metals and with the ratios of simultaneously extracted 

 metals (SEM) to acid-volatile sulfides (AVS) in Phase 2 sediments (n=20). 



ns = not significant (p>0.05). * p<0.05 ** p<0.001 

 SEM = (sum of Cd, Cu, Pb, Ni, Zn) 



The Spearman-rank correlation coefficient for amphipod survival and the concentration of un-ionized 

 ammonia in the overlying water in the amphipod test chamber was not significant (Rho = -0.105, 



96 



