higher than the corresponding lead values. For most marine 

 species, arsenic exists as arsenobetaine, a water soluble 

 organoarsenical compound that poses little threat to human 

 consumption or to the organism (Eisler, 1988). The data 

 indicates that a direct correlation cannot always be made 

 between the residues found in the sediment to those found in the 

 biota residing in that particular sediment. 



Arsenic values were comparable to the cadmium values in 

 zooplankton and phytoplankton (Table 4). The lead values 

 were probably unrealistically high (8. 1-215 ppm, dry weight), 

 based on work of other investigators (Flegal, 1985). Flegal 

 found that phytoplankton residues, collected from the central 

 Pacific Ocean, contained 0.04 ppm lead (fresh weight) and 

 zooplankton contained 0.05 ppm lead (fresh weight). We 

 suspect that these high values may have been due to 

 contamination from the ship's hull since the paint and rust 

 chips from the ship were known to contain lead. The plankton 

 tows were made only 15 to 20 m below the surface of the water 

 and lead in the plankton and the neuston may have been 

 contaminated by the rust or paint chips. These data should be 

 cautiously interpreted. 



Cadmium and arsenic concentrations in the plankton and 

 neuston may not have been as severely affected by the ship's 

 contamination, but these findings should be viewed with caution 

 because we do not definitely know the chemical contents of the 

 paint and rust chips from the ship. For example, our values for 

 cadmium (Table 4) were lower than those collected in the 

 northeast Pacific Ocean where Martin et al. (1975) found 

 cadmium concentrations ranging from 2.0 to 5.0 ppm (dry 

 weight) except 10 to 20 ppm (dry weight) off Baja, California. 

 To avoid problems with contamination from the ship, these 



investigators collected their samples from an inflatable dinghy 

 rowed several hundred meters away from the ship. However, 

 they found their cadmium data to be comparable to their data 

 on the previous cruise when they performed their plankton 

 tows directly off the research vessel. 



Both arsenic and cadmium tended to be elevated in these 

 marine biota because of their ability to accumulate these 

 contaminants from the seawater or food sources and not due to 

 localized pollution (Eisler, 1985, 1988). We have no reason to 

 suspect that the water column was severely contaminated, even 

 though we did not analyze the water column for arsenic and 

 cadmium. There are, however, cadmium values for water that 

 were collected from the Bering Sea during the Second ( 1984) 

 Joint US-USSR Expedition (Montgomery & McKim, personal 

 communication). During the 1984 expedition, they found 

 cadmium in the water column ranging from <5.0 to 100 ng 1. 

 They used differential pulse anodic stripping voltametry and a 

 rotating disk electrode to make these measurements. 



Cadmium especially tends to accumulate in a marine 

 organism with the age of the organism (Eisler, 1985). In view 

 of these facts, a likely explanation for the high cadmium 

 concentrations found in walruses by Taylor and coworkers 

 could be linked to longevity and not to pollution sources. To 

 further explain the high concentrations of cadmium in walruses, 

 more research is also needed to determine how much cadmium 

 is bioaccumulated in the food chain. 



We wish to thank Mark Abramovitz. Steven Boateng, and 

 Brenda Cheek for their able assistance in preparing these samples for 

 analyses. The patience and expert assistance of the crew of the 

 Akademik Korolev are deeply appreciated. We also wish to thank 

 Texas A&M University for the use of their box corer and other coring 

 equipment that was provided to us. 



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