tDDT, however, mussels at these sites 

 are not highly contaminated. If fine- 

 grained sediment had been available, it 

 is unlikely thattheirchemical concentra- 

 tions would be among the high concen- 

 trations. 



NS&T sites along the stretch of coast 

 from Point Conception, CA, to the Hood 

 Canal, WA, provide an example of sedi- 

 ment concentrations that are high due to 

 natural, rather than human, causes. 

 Levels of human population and indus- 

 trialization are low, but a few metals 

 appear at high concentrations. Chro- 

 mium concentrations in sediments are 

 high, most likely because mineralsform- 

 ing the bedrock of that region are also 

 enriched in chromium (USGS, 1981). 

 High chromium concentrations in sedi- 

 ments elsewhere in the nation can be 

 attributed to human activity and consid- 

 ered to be contamination, but in the 

 Northwest chromium is naturally high 

 and is not a contaminant. This point will 

 become important as we discuss levels 

 of chemicals in sediments that have 

 been found to produce biological re- 

 sponses. 



Biological Effects Of 

 Contaminants 



A crucially important aspect of chemical 

 contamination is whether or not it is 

 causing any biological effects. One 

 approach to that question is to collect 

 and examine organisms living at each 

 site. The other is to expose test organ- 

 isms to sediment samples and use the 

 organism's response as a measure of 

 toxicity. Both methods are being used in 

 NOAA's NS&T Program. 



The presence of tumors in fish is usually 

 interpreted as a response to contamina- 



tion (Susani, 1 986) , and livers of fish col- 

 lected at all NS&T sites have been 

 examined for them. They were found in 

 only 36 of the approximately 5,600 fish 

 examined between 1984 and 1986. 

 Fourteen of those were found in winter 

 flounder in Boston Harbor, MA, and five 

 in English sole in Elliott Bay, WA. These 

 two areas do appear in the Appendix 

 and Figure 2 as having sediments with 

 high concentrations of chemicals. Two 

 fish with liver tumors were found at each 

 of four other sites: Raritan Bay, NJ; 

 Great Bay, NJ; Bodega Bay, CA; and 

 Commencement Bay, WA. Two of those 

 sites. Great Bay and Bodega Bay, have 

 not shown evidence of chemical con- 

 tamination. So, while there is a general 

 connection between contamination and 

 liver tumors in fish, tumors are not al- 

 ways found in places where contamina- 

 tion is high, and they are occasionally 

 found in what might be considered 

 uncontaminated areas. 



Complicating factors include the facts 

 that older fish have a higher frequency 

 of tumors than younger fish, and that 

 even under identical exposures to con- 

 tamination, different species of fish 

 metabolize contaminants at different 

 rates and are more likely than others to 

 develop tumors (Varanasietal., 1987). 

 The observations in the NS&T Program 

 are not all on older fish and, because it 

 is a national program, the focus cannot 

 be on a single species, i.e., no single 

 species of fish is found at all sites. The 

 infrequent occurrence of liver tumors is 

 related to the species examined, but is 

 due also to liver tumors being an ex- 

 treme response to contamination and 

 the fact that NS&T sites are not isolated 

 areas of extreme contamination. 



Recent work by Long and Morgan (1 990) 



