This summer an ambitious research project is surveying 10 different glaciers on Svalbard to determine if increased levels of heavy metals in Arctic animals are related to increased glacial river flows and new, exposed land in the region.
In the past few years, scientists have noticed increased levels of heavy metals in Arctic animals such as seabirds, polar bears, brown bears, and salmon.
At the same time, due to climate change, glaciers in the region are retreating and exposing large swaths of land previously covered by ice. In some studies, meltwater from these areas have been shown to contain increased levels of heavy metals; metals like lead, mercury, cadmium, and arsenic.
It takes no great detective to suspect a link between these two facts.
But science does not work like that. Correlation does not mean causation, and more proof is needed to establish a connection. Because how do these metals make their way through the ecosystem from melted glaciers and, ultimately, to the plates of people living in the Arctic?
This question is precisely what METALLICA, a research project funded by the Norwegian Research Council, is trying to answer.
“No one has been able to work out why we are seeing increased levels of heavy metals in Arctic birds and mammals,” Jemma Wadham, Professor of Glaciology at the Department of Geosciences at UiT – the Arctic University of Norway told Polar Journal AG.
“But now that we know that glaciers are microbially active environments, where rocks are being crushed and ground up into very fine reactive particles, we are interested in seeing if they could be the source,” she said.
From phytoplankton to seabird
To investigate this, Jemma Wadham and her colleagues have picked 16 different glaciers: 10 on Svalbard and 6 in mainland Norway. From each of these glaciers they are collecting water samples; at the glaciers themselves, further downstream, and even by boat in open water.
“Some of these glaciers are in very remote locations, so our fieldwork usually involves carrying a lot of heavy gear high up into the mountains, and then following the water down as it runs into the fjords,” Jemma Wadham said.
Last year, they tackled the hikes to the glaciers in mainland Norway and this year they have been collecting samples on Svalbard. And although the work has been hard, the effort has been worth it. Because, according to Jemma Wadham, the many different locations has allowed them to do something no other research project has done before.
“All the glaciers in the project sit on different types of rock, and the rock is an important source of metal species. So by comparing the different rock types, we hope to understand what may be causing the release of metals in the different types of systems in the Arctic,” she said.
And in Kongsfjorden on Svalbard, the project is going a step further. Here, the Norwegian Polar Institute has kept a meticulous long-term record of the fjord’s biological life over the decades. This allows the Metallica researchers to trace the metals released by the glacier and investigate its effect on animal life.
“We are looking at how the metals have affected different parts of the food web, tracking it all the way from phytoplankton to a bird or a fish. To cover all this our group of researchers consist of microbiologists, chemists, plankton biologists, and experts studying seabirds and large mammals,” Jemma Wadham, who is a glaciologist, said.
Climate change has exposed new areas
But why, then, would levels of heavy metals have increased? Glaciers have always ground rock into its component parts, and if they are retreating, you would expect this process to happen less, not more.
Well, Jemma Wadham and her team have a theory.
“With climate warming, glaciers are retreating and exposing new land; land that was once beneath the glacier but is now in contact with the atmosphere. With the melting you would also expect an increase in river flows from beneath glaciers and across the newly exposed lands, and you would expect the rivers to pick up more sediment,” she said.
Sediment is an important part of the process. This is where a lot of the heavy metals from the glaciers end up as many heavy metals bind well with sediment, Jemma Wadham explained. Moreover, there might also be permafrost melting in the ground around the glacier, increasing the release of metals.
“It is really about the retreat of the glacier, the changes around it, and the higher amount of sediment and run-off that is produced,” she said.
Important anywhere with glaciers
The heavy metals released into fjords and ecosystems each have different effects, many of them toxic to humans. Mercury, for instance, is neurotoxic, and human release of it is being fought through an international treaty named the Minamata Convention on Mercury.
The convention took its name from the Japanese city of Minamata where methylmercury was released into local ecosystems through wastewater from a chemical factory. Over a period of decades, this caused thousands of people to develop a neurological condition now known as Minamata Disease.
“Consuming any of these metals over a long period of time is dangerous, and something we all want to avoid. That’s why this project is important, not only in the Arctic but anywhere where glaciers are retreating,” Jemma Wadham said.
Once the Metallica project is done, Jemma Wadham hopes to produce a map. The map will show which glaciers are releasing heavy metals and which are not. Based on the geology under these glaciers, the scientific community would then, if things go well, be able to extrapolate to other parts of the Arctic and the world, and predict which areas are in danger of heavy metal release.
“The answer might also be that glaciers are not involved at all. This is research, so we are keeping that possibility open,” Jemma Wadham said.
Ole Ellekrog, Polar Journal AG
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