Table 8 continued. 



a Percent survival relative to seawater controls. 



* Significantly different from controls (t-test, alpha = 0.05). 



** Significantly different from controls and 80% or less than the control response. 



The spatial patterns in toxicity for the two end-points of this test are illustrated in Figures 9 through 12. 

 As with the pattern seen in the Ampelisca abdita survival test, the bivalve larvae survival test indicated 

 relatively high toxicity in the upper East River stations, diminishing eastward into western Long Island 

 Sound (Figure 9). Also, samples from Kill van Kull (site 17), inner Sandy Hook Bay (site 30), and two 

 offshore sites (37 and 39) were toxic in this test. Based upon the site means, toxicity in this test was 

 high in sites 6, 7, 17, and 30 (Figure 10). 



The percent normal development end-point also indicated high toxicity in sediments from sites 5-8 in 

 the upper East River and western Long Island Sound (Figure 1 1 ). However, toxicity to this test did not 

 diminish nearly as much into western Long Island Sound as in the amphipod and bivalve survival tests. 

 Sediments from sites 4 and 5 were more toxic to bivalve normal development than to amphipod or 

 bivalve embryo survival. The very high toxicity indicated by the amphipod survival test in the Newark 

 Bay/Arthur Kill area (sites 16-18) was not as apparent in the bivalve larvae development tests. Sedi- 

 ments from site 16 at the head of Newark Bay were very toxic to amphipods, but not to bivalve larvae. 

 Site 17 sediments were toxic in the survival test, but not in the development test. 



45 



