Correlations between percent survival of A. abdita and the concentrations of trace metals and total 

 organic carbon in the EMAP samples are summarized in Table 2. Survival would be expected to 

 diminish among amphipods exposed to increasing concentrations of toxicants, resulting in negative 

 correlation coefficients. The correlations were conducted with the trace metals data normalized to dry 

 weight, aluminum concentrations, and TOC concentrations. A significant negative correlation be- 

 tween survival and chemical concentrations normalized to dry weight was observed only for antimony 

 (Rho = -0.480, p<0.05, n=9). The correlations between percent survival and trace metals concentra- 

 tions improved when the chemical data were normalized to TOC content; the correlations with lead, 

 cadmium, antimony, and tin were significant. When the trace metals data were normalized to the 

 aluminum concentrations, many of the correlations became highly significant. For example, the corre- 

 lations between percent survival and the concentrations of cadmium, copper, antimony, and tin were 

 highly significant, and those with nickel, zinc, and selenium were significant. The correlations be- 

 tween percent survival and the concentrations of aluminum and TOC content, however, were not sig- 

 nificant. 



Table 2. Spearman-rank correlations (Rho) between percent survival of A. abdita (n=9) and the 

 concentrations of trace metals normalized to dry wt., aluminum, and total organic carbon (TOC). 

 From U.S. EPA EMAP monitoring data, 1990 (Schimmel et al., 1994). 



* p< 0.05 nd = no data 



**p<0.01 



*** 



p< 0.001 



These relatively high correlations between amphipod survival and chemical concentrations were unex- 

 pected since the nine samples were collected in widely separated portions of the study area. They were 

 not collected near each other within the zone of influence or dilution gradient of one point source. 



Battelle Pacific Northwest Laboratories tested sediment samples from 20 locations in the estuary for 

 the City of New York (Tom Brosnan, City of New York, personal communication; Brosnan and O'Shea, 

 1993). The samples were collected throughout the estuary in February, 1992 and tested with a flow- 



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