METHODS AND MATERIALS 



NOAA initiated an area-wide survey of sediment toxicity in 1991 to provide internally consistent data 

 on the spatial extent and severity of toxicity to relatively sensitive taxa. The intent of this survey was 

 to sample all of the major regions of the study area, collect surficial fine-grained sediments, and test 

 them to determine the degree of toxicity to laboratory organisms. 



Based upon available sedimentological, chemical and biological data from numerous studies, a strati- 

 fied sampling design was prepared that embraced areas previously identified as highly, moderately, 

 and slightly contaminated. To ensure that samples were collected throughout the entire estuary, the 

 study area was stratified into 13 contiguous regions designated as zones A through M (Figure 4). These 

 zones were established following review of available bathymetric, physiographic and sedimentologi- 

 cal information to represent conditions within major components of the study area. For example, zones 

 A and G were intended to represent conditions in the lower reaches of the Hudson and Raritan rivers, 

 respectively. Zones C and D were intended to represent conditions in the upper and lower reaches of 

 the East River, respectively. Zones H through K were selected to represent the different sedimentologi- 

 cal and bathymetric regimes reported in Raritan Bay. Samples from zones B and M were intended to 

 provide information from suspected reference areas. 



Three sites were sampled within each zone (Figure 4) to provide information on environmental vari- 

 ability. Most sites were chosen based upon reviews of data from previous sedimentological and chemi- 

 cal analyses (e.g., City of New York, 1987). Where no historical data were available, the sites were 

 selected based upon bathymetric and sedimentological information published on applicable navigation 

 charts. The coordinates for the center of each site are listed in Table 4. Similar to the method used in 

 NOAA's Mussel Watch Program (NOAA, 1987), three stations were sampled and tested independently 

 within each site. Sediments from a total of 39 sites and 117 stations were sampled and tested. 



Table 4. Locations of sites in the Hudson-Raritan Estuary sampled during Phase 1. 



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