Minor elements in sediments of Great Bay estuary, New Hampshire

Concentrations of copper, zinc, chromium, lead, cadmium, and phosphorus were obtained from 81 samples of unconsolidated estuarine sediment from Great Bay, New Hampshire. Dispersal of aqueous chromium from localized industrial effluent is believed responsible for an increase in sediment chromium throughout the entire estuary. High phosphorus concentrations exist in sediment near the outfalls from several waste-water treatment plants. There is no evidence for any increase of copper, zinc, lead, or cadmium in this estuary, except for localized high concentrations close to industrial outfalls. Fine-grained sediments and organic carbon correlate highly with all the elements studied, except for chromium. This suggests that conventional agents of sedimentary adsorption are not adequate to explain the incorporation of chromium into sediment under the conditions of heavy industrial discharge which exist in this estuary. Sediment phosphorus correlates highly with minor elements, suggesting that it is an adsorption agent, similar to more typical sedimentary parameters such as organic matter and clay minerals. In such a capacity phosphorus may enhance the sedimentary uptake of other aqueous species, and account for higher chromium sediment concentrations. Comparative data from other sedimentary environments emphasize the environmental significance of these elements in Great Bay