Uranium-Series Nuclides in Sediment, Water, and Biota of Saqvaqjuac Inlet, a Subarctic Estuary, N.W. Coast Hudson Bay

Abstract

Saqvaqjuac Inlet (63°39′N., 90°39′W.) is a fjord-like estuary of the Saqvaqjuac River on the northwest coast of Hudson Bay. Surface water salinities vary from 5–30‰, and deeper water is 33–34‰ and sometimes anaerobic. Isolated and shallow-silled small bays of the inlet have anaerobic, hypersaline (up to 100‰) deep waters. River discharge and atmospheric deposition are major sources of Pb-210 and Po-210, and these nuclides are inversely related to salinity. Sea water inputs from the tides, and sediment diagenesis appear to be sources of U-238, Ra-226, and Th-230, and they are positively related to salinity. Hypersaline anaerobic waters are usually depleted in U and Ra, and enriched in Pb-210 and Po-210. Bioconcentration factors for these nuclides in estuarine biota will be given, and the highest factors (10⁵ to 10⁶) were found for Pb-210 and Po-210 in hepatopancreas of crabs and pyloric caecae of Greenland cod.