Norwegian seabirds are facing an existential crisis and an uncertain future weighed by mercury levels found to be above the safe thresholds for healthy reproduction, raising serious concerns amongst scientists for the species’ chance for survival.

Life in Svalbard is already pushed to the extreme. Compounded by levels of mercury exceeding the thresholds for ‘deleterious effects on reproduction’ and things for the region’s population of seabirds such as kittiwakes, is about to become trickier.

Mercury is toxic to both humans and animals even in small concentrations. It affects the hormonal and immune systems and can cause damage to the nervous system.

“We don’t know what effect this has on the population level, but we know that mercury affects reproduction, behaviour, and survival,” said Silje Lundgren, a researcher from the Norwegian University of Science and Technology’s Department of Biology.

Lundgren is part of a team of researchers to have recently studied the occurrence of a number of heavy metals and environmental toxins in Svalbard birds as part of her master’s thesis at the University, a project supervised by Professor Veerle Jaspers.

The research dates back to 2017, when Lundgren collected samples of feathers from adult black-legged kittiwakes and Brünnich’s guillemots in an area of Svalbard known as Kongsfjorden, alongside samples of blood plasma from the kittiwakes.

The results – which have since been published in the scientific journal Science of the Total Environment – showed high levels of mercury in both species, with the level in the kittiwakes exceeding the threshold for potential reproductive effects.

In the kittiwakes, in particular, the level of mercury was found to be higher than what has been found in all previous studies of seabirds in the Arctic.

“High concentrations of mercury will not necessarily have a negative impact on the individual level, but seabirds in general are struggling with survival and reproduction and mercury can be a factor contributing to population decline, along with other things,” said Lundgren.

Mercury is a heavy metal that exists in the environment in different chemical forms, the most toxic being organic mercury known as methylmercury. Mercury occurs in nature and can originate from sources such as volcanic eruptions or gasification. Human activity – such as mining and industry – can also lead to high mercury emissions.

Methylmercury is particularly hazardous during pregnancy and can be transferred from mother to foetus with large quantities often leading to malformations. It also affects the cognitive development of both foetuses and infants and can lead to impaired motor skills.

Today, fish and other seafood – especially lean fish – are the main source of mercury in our own diets.

It’s true that Svalbard’s seabird populations are facing something of a crisis. Climate change, pollution, loss of breeding areas, hunting, and diseases have been found to be the root cause of some serious dips in population numbers. Norway’s national monitoring programme (SEAPOP) currently follows 35 species of seabirds; of these, 13 species have been reduced by more than 50% in the last 20 years.

In the Arctic – where the temperature increase due to global warming has been the highest in the world, land ice is now melting. It’s a hypothesises that this melt is releasing metals and environmental pollutants previously locked away in snow and ice, which are now making their way into the food chain.

“The lion’s share of the pollution in the Arctic comes from Asia, where they have high consumption of coal, including in industrial production,” said Geir Wing Gabrielsen, a researcher from the Norwegian Polar Institute – a keen observer of Norwegian seabird populations over the past few decades.

“When air masses blowing north meet northern winds, the pollution is deposited in snow and ice.” 

In Svalbard, 57% of the land area is covered by glaciers, and over 900km of the coastline has glaciers that break off into the sea. Each year, some 45 billion tonnes of meltwater mixed with sediments flows into the coastal waters in the region. At the same time, climate change is causing warm, Atlantic water to flow northward, bringing with it animals and other organisms from lower latitudes.

This in turn has driven a shift in the trophic system and seabirds such as kittiwake and the Brünnich’s guillemot – which previously lived on polar cod – have switched to eating Atlantic fish species, such as herring, capelin, and krill.

While researchers note that this has had some positive effect on seabird species in Svalbard, offering them greater access to food sources, connections are being made between what they are now eating and their rising mercury levels.

At the root of the issue, however, are mercury emissions. According to the Arctic Monitoring and Assessment Programme, countries across Asia accounted for half of the world’s mercury emissions back in 2015. Much of this was released through coal use.

“Today, industry produces 250,000 different environmental pollutants that are released into the natural environment via the atmosphere, rivers, and ocean currents. The chemical industry is the fastest growing in the world,” said Gabrielsen.

Researchers at the Norwegian University of Science and Technology now have an ongoing project partnership with the Norwegian Institute for Nature Research looking into the Interactive effects of pollutants and climate on seabirds in Arctic Coastal ecosystems.

“Mercury is also one of the priority pollutants under investigation in that project, meaning we will follow up on the levels in different seabirds along with their population trajectories in Norway and on Svalbard,” said Professor Jaspers.

The study – Metals and other trace elements in plasma and feathers of seabirds breeding in Svalbard – is published in the scientific journal Science of the Total Environment.

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