Is mercury from outside the Arctic polluting the region and how does climate change affect mercury in the Arctic biotic interactions?
Yes, mercury from outside the Arctic is a major source of pollution in the region. Most of the mercury contamination comes from long-range transport through air and water currents, with sources like:
- Industrial activity in Asia, Europe, and North America [Arctic Council]
- Coal burning power plants [This is a well-known source, you can find more info by searching online]
This highlights that the Arctic is susceptible to pollution even though it may not have the major sources within its borders.
Climate change is making the situation worse in a couple of ways:
- Melting permafrost: Permafrost acts as a giant storage locker for mercury trapped for years. As the permafrost thaws, this mercury is released back into the environment [Science.gc.ca]
- Changes in water circulation patterns: Shifting currents due to climate change can redistribute existing mercury deposits, potentially exposing new areas or increasing the amount reaching the food chain.
These factors combine to increase the risk of mercury bioaccumulation and biomagnification in the Arctic ecosystem. Here's a breakdown of these terms:
- Bioaccumulation: The buildup of mercury in organisms as they consume contaminated prey.
- Biomagnification: As you move up the food chain, the concentration of mercury gets even higher in predators.
This means that top predators like polar bears and whales end up with the highest levels of mercury, posing a health risk to them and humans who rely on them for food.