ambient concentrations of toxicants in finfish and shellfish tissues with existing standards. The con- 

 centrations of PCBs, tcdd (dioxin), mercury, chlordane, and dieldrin in samples from the estuary often 

 exceeded the standards and were noted as chemicals of high concern. Other contaminants listed as 

 chemicals of moderate concern included arsenic, tDDT, heptachlor, heptachlor epoxide, 

 hexachlorobenzene, lindane, numerous aromatic hydrocarbons, and tcdf (furans). 



In the absence of any applicable sediment quality standards, Squibb et al. (1991) compared ambient 

 concentrations of contaminants in sediments with the ERL and ERM values identified by Long and 

 Morgan (1990). In their investigation, Squibb et al. (1991) evaluated data from many different studies, 

 merged the data for selected regions within the estuary, and compared the average, maximum, and 

 minimum concentrations within each region with the effects ranges of Long and Morgan (1990). Where 

 the abundance of data warranted, they treated four subregions of Raritan Bay separately: (I) Western 

 Raritan Bay at the confluence of the Raritan River and Arthur Kill; (II) central Raritan Bay stretching 

 from Staten Island to Sandy Hook Bay; (III) northern Raritan Bay bordering the lower New York 

 Harbor; and (IV) southern Raritan Bay along the New Jersey shore. 



Squibb et al. (1991) determined that the concentrations of eight trace metals, PCBs, tDDT, chlordane, 

 dieldrin, tPAHs, and six aromatic hydrocarbons exceeded the ERM concentrations in samples from at 

 least one area within the estuary. In addition, the concentrations of six other aromatic hydrocarbons 

 exceeded the ERLs, but not the ERMs. Squibb et al. (1991) concluded that there was a substantial 

 potential for toxicant-associated biological effects in the sediments of the estuary. 



Table 1 summarizes the patterns in exceedances of the ERL and ERM values described by Squibb et al. 

 (1991). Exceedances of the effects ranges were largest and most frequent in sediments collected (in 

 decreasing order) in Newark Bay, Arthur Kill, Gowanus Canal, Hackensack River, lower Jamaica Bay, 

 and near Ward's Island (at the mouth of the Harlem River) (Table 1 ). The areas in which the chemical 

 concentrations least frequently exceeded the effects ranges were the Harlem River, southern Raritan 

 Bay, and northern Raritan Bay. 



Table 1. Regions of the Hudson-Raritan Estuary in which the concentrations of selected toxi- 

 cants in sediments exceeded respective effects ranges of Long and Morgan (1990). Adapted from 

 Squibb et al. (1991). 



