Levels of organic contaminants in invertebrates from the hudson river estuary

Few studies have quantified organic pollution levels in invertebrates in the HR ecosystem. The New York State Department of Environmental Conservation (NYSDEC) maintains a database on a suite of organic and inorganic contaminants analyzed in fish and wildlife tissues from the 1970s to the present. Entries for invertebrates in the HR are limited, with PCBs being the only contaminant consistently detected. Total PCBs in samples of aquatic insects collected in 1999 above Hudson Falls generally ranged from 1 to 10 ppm. Levels of PCBs in crayfish and physid snails collected from the same locations had lower PCB concentrations, ranging from 0.1 to 6 ppm, with PCB concentrations in grass shrimp collected downriver near Yonkers ranging from 0.3 to 0.5 ppm. Although data are limited, invertebrates, particularly those found in the upper reaches of the river, may still serve as a significant source of PCBs to the HR food web.

In 1993, NYSDEC conducted a large survey of contaminantlevelsinfinfish, bivalves, crustaceans, and one squid species from different regions of the NewYork Harbor (Skinner et al., 1997). Levels of total PCBs in softshell clams Mya arenaria were generally low, averaging from <0.03 to 0.32 ppm. In lobster Homarus americanus and blue crabs PCB levels in muscle tissues were also low, averaging 0.03 to 0.07 ppm, but levels in hepatopancreas were much higher, averaging 6.6 to 13.2 ppm and were similar to levels reported in an earlier survey in 1982 and 1983 (Belton et al., 1985). Organisms collected from the upper Harbor region (which includes the portion of the HR below the George Washington Bridge) tended to show the highest body burdens. Body burdens of total DDT and chlordane were lower with average concentrations even in hepatopancreas being less than 1 ppm in blue crabs and lobster.

In 1998 and 1999, NYSDEC conducted studies on the health of benthic invertebrate communities in thirty-two tributaries of the HR from RM 18 to RM 150 to identify those that are major sources of contaminants to the main stem river (Bode et al., 2001a). Invertebrates, including caddisflies, crayfish, and helgrammites, from roughly 50 percent of the streams exceeded state levels of biological concern for PAHs, metals, or pesticides while only 15 percent showed exceedances for PCBs. In thirteen tributaries studies in more detail, total PCBs exceeded 1 ppm only at one locale, but almost all sites exceeded state levels of concern (Bode etal., 2001b).

Populations of marine bivalves at almost 300 sites nationwide have been used as integrators of environmental chemical contamination in a variety of federal programs collectively termed Mussel Watch. In 1986 and 1987 sampling, some of the highest PAH concentrations nationwide were reported for mussels Mytilus edulis collected from the Hudson/Raritan Estuary (3 of 3 sites exceeded 5 |g/gdw). PCB levels in mussels were also high, but lower than those in Buzzards Bay, and comparable to those in Boston Harbor. Total DDTs were also highest at one of the Hudson/Raritan sites, 550 ng/gdw, with levels at other Hudson/Raritan sites comparable to those observed in other urban estuaries (Boehm et al., 1988).

A number of new organic compounds, mostly newer pesticides and chlorinated benzene were added in the 1990s to the Mussel Watch analyte list (Wade et al., 1998). One of these, chlorpyrifos, was detected in mussels from two of the Hudson/ Raritan sites at concentrations exceeding 10 ng/ gdw ranking well above the nintieth percentile of all measurements made. Given the high levels of nonylphenol ethoxylate metabolites recently measured in some portions of the lower HR estuary, consideration should be given to their inclusion in the Mussel Watch program.

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