Levels of nutrients, alkalinity, and total carbonate are related to the different water masses in the Laborador Sea, which include winter Labrador Sea Upper Water, Labrador Sea Water, North Atlantic Deep Water, and Northwest Atlantic Bottom Water. Alkalinity values in the Northwest Atlantic Bottom Water are consistent with a cyclonic flow around the periphery of the Labrador Sea and near-stagnant conditions in the center. Nitrate and oxygen concentrations, combined to form the conservative tracer NO and taken together with potential temperatures, suggest that North Atlantic Deep Water and Northwest Atlantic Bottom Water in the Labrador Sea are part of a continuum of overflows at different densities from the Norwegian-Greenland Sea region. NO values also suggest that neither of these water masses contains significant amounts of Mediterranean Sea Water or Antarctic Bottom Water.