Anthropogenic lead pervasive in Canadian Arctic seawater.

Anthropogenic Pb is widespread in the environment including remote places. However, its presence in Canadian Arctic seawater is thought to be negligible based on low dissolved Pb (dPb) concentrations and proxy data. Here, we measured dPb isotopes in Arctic seawater with very low dPb concentrations (average ∼5 pmol ⋅ kg) and show that anthropogenic Pb is pervasive and often dominant in the western Arctic Ocean.

A new method to extract Th, Th and Pa from seawater using a bulk-extraction technique with Nobias PA-1 chelating resin.

The long-lived radioisotopes of Th and Pa are unique tracers for quantifying rates of biogeochemical processes in the ocean. However, their generally low concentrations (sub-fg/kg for Th and Pa and pg/kg for Th) in seawater make them difficult to measure. Here, we present a new approach to determine Th and Th using Nobias PA-1 chelating resin following a bulk-extraction technique, and report for the first time the use of this resin to measure Pa concentrations.

Anthropogenic Asian aerosols provide Fe to the North Pacific Ocean.

Fossil-fuel emissions may impact phytoplankton primary productivity and carbon cycling by supplying bioavailable Fe to remote areas of the ocean via atmospheric aerosols. However, this pathway has not been confirmed by field observations of anthropogenic Fe in seawater. Here we present high-resolution trace-metal concentrations across the North Pacific Ocean (158°W from 25°to 42°N).

Diel changes in trace metal concentration and distribution in coastal waters: Catalina Island as a study case.

Understanding biogeochemical cycling of trace metals in the ocean requires information about variability in metal concentrations and distribution over short, e.g., diel, time scales.