CARBON-DISULFIDE IN THE ESTUARINE, COASTAL, AND OCEANIC ENVIRONMENTS

The concentration of carbon disulfide (CS2) in surface water and relevant hydrographic parameters were determined in coastal waters of the eastern USA (Delaware Bay and Chesapeake Bay, including the Potomac River; 7-11 September 1986). The CS2 Concentration varied extensively along the cruise track, from 4 to 510 pmol S(CS2) l-1 (n = 103). The average values in estuarine, shelf, and oceanic waters were found to be 118 +/- 100 pmol S(CS2) l-1 (n = 54), 51 +/- 34 pmol S(CS2) l-1 (n = 14), and 28 +/- 12 pmol S(CS2) l-1 (n = 35), respectively. To help interpret the geochemical behavior of CS2, we analyzed the depth distribution of CS2 in the North Atlantic Ocean during an earlier cruise (23 April-2 May 1986). In most cases, these depth profiles show a near-surface maximum at about 10-20 m depth and a relatively steep gradient below this maximum. Based on the distribution pattern in the water column and evidence provided by earlier workers, we propose that diffusion of CS2 from bottom sediments may contribute to CS2 levels in surface seawater. The atmospheric concentration of CS2 was also investigated at some locations during the September cruise. Except during periods when there was a significant anthropogenic input, the concentration of CS2 in air was generally in the range of 4-15 pptv (parts per trillion by volume) with a mean of 10.4 +/- 4.0 pptv (n = 10). The calculated sea-to-air emission rates of CS2 at each of our sampling stations show a decreasing trend across estuarine, shelf, and oceanic areas, in agreement with the trend in surface water concentrations.