Arctic Mercury Cycle Could Be Linked to Ice Cover Extent

In a new scientific study, researchers propose for the first time that the mercury cycle taking place in the Arctic and adjacent areas may have a direct influence on the ice cover extent at and around the North pole. These conclusions were derived from a multi-year joint research effort.

The chemical cycles through the flora and fauna of the Arctic, researchers say, and its circulation patterns may be linked to the amount of ice that forms and melts every single year.

Scientists came to these conclusions serendipitously, as their study focused on tracking pollution trends in the northern marine environments. They did so by using seabird eggs, which contain elevated or lower levels of certain tracer chemicals, depending on how much pollution they are exposed to.

This effort was conducted by experts at the National Institute of Standards and Technology (NIST), who worked with colleagues from the Charleston, S.C.-based Hollings Marine Laboratory (HML).

The research was conducted as part of the multi-year joint effort called the Seabird Tissue Archival and Monitoring Project (STAMP), which is being conducted by several US agencies and organizations.

The main collaborators in STAMP are NIST, the US Geological Survey (USGS), the US Fish and Wildlife Service (USFWS), and the Bureau of Indian Affairs. These agencies seek to ensure that pollution levels are kept in check in the Arctic.

In the new research, experts focused on analyzing mercury isotopes, and a chemical effect called mass-independent fractionation (MIF). Total mercury levels at the North Pole have been under monitoring since the early 1990s.

“With the potential for global warming to dramatically reduce Arctic sea ice in the future, the relationship between ice cover and distribution of mercury in the environment is obviously an important one to investigate further,” a NIST press release reads.

“The international research team next plans to use its seabird egg isotope monitoring system to distinguish the sources of mercury contamination in coastal areas to those from oceanic waters,” it adds.

One of the most important findings in the new study was that murre eggs collected from the northernmost nesting areas during the research effort revealed lower amounts of MIF mercury isotopes than eggs from southern Alaska.

This effect may be caused by variations in ultraviolet (UV) light exposure that the two areas get. UV is known to break apart mercury in a process called photodegradation, EurekAlert reports.