Table 36. Average concentrations of PAHs (ng/g, dry wt.) in highly toxic (<80% survival) and 

 nontoxic samples from Phase 2, ratios between the averages, and ratios between the highly toxic 

 averages and the respective SQGs. 



a Long et al. (1995) 

 b U.S. EPA (1994) 



DISCUSSION 



Incidence and Severity of Toxicity. In previous studies and surveys of the Hudson-Raritan Estuary, 

 many investigators have reported that portions of this area were highly contaminated with a variety of 

 potentially toxic chemicals (O'Connor and Ehler, 1991; Breteler, 1984; Squibb et al., 1991; Long and 

 Morgan, 1990; Schimmel et al., 1994). The concentrations of many substances equalled or exceeded 

 known toxicity thresholds and exceeded concentrations observed in many other estuaries in the USA. 

 Therefore, based upon these historical chemical data, there was a potential for contaminant-induced 

 toxicity in water, sediments, and resident biota. 



The spatial patterns in chemical concentrations compiled by Squibb et al. (1991) suggested that New- 

 ark Bay and Arthur Kill would be highly toxic. Based upon the data from the present survey, many of 

 the samples from these two areas, indeed, appeared to be toxic. The data assembled by Squibb et al. 

 (1991) also suggested that the following areas would be moderately toxic: East River bays, East River 

 in the vicinity of Ward's Island, upper New York Harbor, Gowanus Canal, lower Hackensack River, 

 and lower Jamaica Bay. Among these areas, samples were collected in the present survey in the upper 

 East River near Ward's Island, upper New York Harbor, and the lower Hackensack River. The samples 

 collected in the East River were highly toxic, those from the lower Hackensack River were moderately 

 toxic, and those from the upper New York Harbor were not toxic at one site and moderately toxic at 

 another site. The northern and southern portions of Raritan Bay, which were highly sandy, were ex- 

 pected to be among the least toxic areas according to the data compiled by Squibb et al. ( 1 99 1 ), and that 

 was confirmed in the present survey. Although conditions in all of these areas were heterogeneous, the 

 overall patterns in toxicity suggested by the chemical data from previous surveys generally were con- 

 firmed by the toxicity tests in the present survey. 



Previous investigators have documented toxicity in sediment samples collected throughout the estuary. 

 The toxicity of sediments to nematode growth (Tietjen and Lee, 1984) was reported in all ten samples 

 that were tested. Toxicity to amphipods was reported in 8% of 10% samples tested in 1990 (Scott et al., 

 1990). Nine of 20 samples collected in 1992 and tested in flow-through tests with amphipods were 



111 



