THREE COVES ON THE LOWER CONNECTICUT RIVER

The lower Connecticut River and its adjacent coves show the interplay of marine and freshwater depositional environments and contain the legacy of human mercury contamination. During the summer of 2011, three coves were cored. Selden Cove, approximately 18 km from the mouth, Lord Cove, approximately 9 km from the mouth and South Cove, less than a km from the mouth. Of the three, Lord Cove is the most removed from the river and South Cove the most connected.

Sediments in all coves where dominated by reddish-brown, clayey silt with rare thin sand layers. C/N ratios in most cores varied between 10 and 17, suggesting mixing of marine and terrestrial organic matter. Coves closer to Long Island Sound contained some of the higher C/N ratios, reaching 20 in Lords Cove and 25 in South Cove. The higher ratios suggest a larger freshwater input, which is counterintuitive. Accumulation rates will need to be determined to see if the higher C/N ratios suggest much lower sea level. At the time of this abstract, mercury levels have only been measured in Selden Cove. They spike to values of over 1000 ppb, at 150 cm, which correlates with Varekamp et al.’s (2003) 1850 datum. Additional data will be available at the time of this presentation.