Project Title: Mercury in the Sediment and Oysters in the Housatonic River Estuary
Bivalve mollusks (mussels and oysters) are used worldwide as indicators of metal pollution and are known to accumulate mercury in their tissues. The Housatonic River generates more than one-third of CT’s seed oysters from its public oyster beds. Mercury contaminated sediment in the Housatonic River estuary poses a threat to the commercial oyster industry and quantifying the relationship between sediment and oyster tissue mercury contents is necessary for oyster habitat restoration efforts. This study examines the mercury concentration in surface sediment and corresponding oyster tissues in the Housatonic River estuary. The goal of this study will be to test the following hypotheses: (1) sediment mercury content will vary in proportion to sediment grain size and organic carbon content (Loss on Ignition) (2) the mercury content in oyster tissue will vary in direct proportion to the sediment mercury content at that location; and (3) oyster tissue mercury contents in lower Housatonic will, on average, be higher than other regional coastal estuaries.
Biology and Marine Studies
New London harbor is the best natural deepwater harbor in CT. The port area comprises the lower 12 miles of the Thames River and includes the city of New London and the towns of Groton, Ledyard and Preston. The Thames river watershed, and the area immediately surrounding New London harbor, have been historically characterized by industrial activity and are urbanized. Previous studies have been inadequate to describe the extent of sediment metal contamination and the spatial variation in sediment types within the river and harbor. This study examines the physical characteristics and metal contamination in sediments within the Thames River/New London harbor complex. The specific objectives of this research are to: (1) conduct a high spatial resolution sampling of the sediment representative of the entire length of the river and harbor areas; (2) measure the chemical (zinc, copper, manganese and iron) and physical (texture, grain size, loss on ignition) properties of the sediment; and (3) determine the extent of anthropogenic metal contamination in the sediment through a comparison of the results of this study with other similar coastal rivers and embayments in Long Island Sound.
Honors College and Marine Studies