FATE OF MERCURY IN THE ARCTIC Michael Evan ... - COGCI

Fate of Mercury in the Arctic 115
record from Nordvestø is providing a unique, perhaps biogenic record of the mid Holocene. The
study is on going and more cores are being analyzed from Nordvestø.
Global and Arctic significance
The peat studies in this work document that not only has anthropogenic activity caused mercury
to accumulate in the Arctic, but also provides apparent support to the fact that anthropogenic
actions, for example closing of chlor alkali plants, in the latest decades has caused a significant
decline in mercury accumulation in the Arctic environment. The peat studies support that the
observed rise and fall in mercury accumulation in recent times is strongly related to coal use
(Shotyk et al., 2003, Appendix C).
Unfortunately, the peat profiles that could be investigated with high time resolution come from
areas of the Arctic where mercury depletion events have not been observed, therefore not answering
the question of if these profiles would look the same, given that they take place in a AMDE active
area.
The core from the Carey Islands, while from an area expected to have AMDEs, is too disturbed
in the active layer to investigate this. Lake and Marine sediments from the high Arctic, coastal site
near Station Nord, may provide some insight into this, once dating results are completed, so that the
cores can be analyzed further, but preliminary comparison with other Arctic sediments, does not
indicate an increased rate of accumulation. This means that mercury being deposited to the Arctic
may be coming out again.
There are three routes that deposited mercury could be redistributed, so that there is no
terrestrial accumulation signature: 1 uptake into the biosystem, 2 transport away from the Arctic
after emission into the marine system or 3. re-emission into the atmospheric system, with
subsequent transport away from the Arctic outside the spring months. Determining a mercury mass
balance for the Arctic should be a future priority.