The State of Svalbard Waters: Paul Renaud
Dr. Paul Renaud is a marine ecologist with over 20 years of research experience in the marine environment around Svalbard.
He currently serves as the research manager at Akvpalan-niva and as an adjunct professor at the University Centre in Svalbard (UNIS).
“Working in the dynamic Svalbard/Barents region where Arctic and Atlantic conditions can switch dominance over shorter or longer time scales, combined with the changes that the heavily glaciated archipelago is undergoing, is like working in a natural laboratory.”
How does the movement of heat affect the Arctic?
Heat moves northward from lower latitudes through atmospheric and oceanic circulation. Cyclones (storms) propagating northward are particularly important vectors of heat transport to the Arctic. Studies show that North Atlantic oceanic circulation plays a key role in influencing air temperature changes in the Arctic.
The warm, cross-Atlantic current that transports heat to the Arctic is known as the North Atlantic Current (NAC), an extension of the Gulf Stream. Cold, deep waters flow southward from the Arctic toward and across the equator.
The part of the NAC closest to Svalbard is called the West Spitsbergen Current. This current, about 100 km wide with temperatures around 6-8°C, is guided by the ocean floor’s shape and stays over the continental slope. As it travels northward it loses about 0.5°C per 100 km. This current is responsible for the ice-free conditions in Isfjorden.
The polar regions are particularly vulnerable to rising air temperatures due to feedback mechanisms that amplify warming. As a result, the Arctic has warmed nearly twice as fast as other regions in recent decades (now estimated to be four times faster).
By 2100, air temperatures in the Arctic are predicted to increase by 7-10°C, depending on our future greenhouse-gas emissions.
Is water a more efficient transport path than air?
Water carries much more heat due to its high heat capacity, meaning that a lot of energy is required to raise the temperature of water compared to the same amount of air. Water also releases more heat than air when it cools down and loses heat more slowly.
You can just imagine a warm current travelling north with cool air flowing above it. That large warm body of water will be able to warm up the air.
In a reverse situation, a cold current with warm air above, the air cannot heat up the ocean. Northern Norway and even Svalbard are habitable due to the NAC, whereas locations at the same latitude in East Greenland are not since the current off the coast originates in the Arctic Ocean.
How do Arctic and Atlantic Ocean influence Svalbard’s fjord systems?
In general, both atmospheric and oceanic heat transport result in 5-10°C warmer climate in Svalbard than in other land areas at the same latitude.
A fjord’s geographical orientation has a larger impact than what the primary influencing water mass is. Northward and eastward opening fjords show a much stronger Arctic conditions than the west Svalbard fjords.
Arctic waters also carry more ice into fjords, whereas Atlantic influence can melt considerable amounts of ice in fjords. In recent years we have started to see the Atlantification of fjords in Svalbard.
Fjords especially in the west coast are influenced by the northwards flowing West Spitsbergen Current, a branch of the warm North Atlantic Current. Warmer waters from the Atlantic are now spilling into the continental shelf and into Svalbard fjords like Adventfjorden and Kongsfjorden. This inflow is making the fjords respond to climate change earlier than fjords situated elsewhere in the Arctic.
How have the waters around Svalbard changed due to warmer climate?
Nowadays west Svalbard fjords are largely ice-free year-round. These waters are also warmer, with summer surface temperatures reaching over 8oC in recent years.
All waters in Svalbard fjords have experienced ‘marine heat waves’ in recent years, where the temperatures are unusually high for at least several days in a row, and sometimes for weeks.
What are the key drivers of those changes?
There are two main processes. The loss of sea ice and warmer oceanic conditions further south in the Atlantic.
Sea ice loss means that the sun’s energy more easily enters the ocean and heats it up, instead of being reflected when the surface is ice covered. This means greater warming, more melting of sea ice, and since the water is warmer, delayed freezing in autumn. This ‘Arctic amplification’ is a feedback system where reduced sea ice leads to even more reductions in sea ice.
Warmer waters in the Atlantic are transported northward with ocean currents and bathe Svalbard in warmer waters.
Of course, central to these drivers is the warming of the whole earth due to human-produced greenhouse gases.
What conditions may we expect in the future?
In the next 10-20 years we see Svalbard continuing the trajectory it is already on. It takes time to change or reverse the momentum of such a large global system.
The longer it goes on, the more likely we are to see more complex manifestations of the changes. Instead of just a few boreal species surviving in Svalbard, we can see larger changes to the way the ecosystem functions.
Also, human-introduced species are more likely to successfully establish in warmer waters.
On a longer time scale, we MAY see a slowing down of the Gulf Stream, but that is by no means a certainty. One major unknown is how much and how fast the freshwater tied up in the Greenland ice sheet will be released into the North Atlantic. A thick fresh water layer may reduce the amount of dense salty water that is produced when ice forms. It is the sinking of this dense water that partly drives the global circulation that Gulf Stream is a part of.
What impact do changing temperatures and acidity have on marine life?
The survival of new arrivals to Svalbard can be enhanced by warmer conditions, leading to a restructuring of the food webs and how the system functions.
More freshwater in the system can have a strong impact on the acidification of seawater. As seawater becomes more acidic it requires more energy for algae and animals to produce calcareous skeletons, affecting coralline algae, molluscs, sea stars, and crustaceans.
Some organisms are damaged directly by more acidic seawater, and some of these also play important roles in the flow of carbon in the ecosystem. Planktonic molluscs are one example that are both a food source for predators and speed the sinking of carbon to the seafloor. Both warming and acidification may reduce their abundance and ability to calcify.
Are changing conditions in Svalbard waters affecting biodiversity?
Most obvious are the larger species, like harbor seals, orcas, and boreal fishlike cod, mackerel, and haddock that are more abundant now. Snow and king crabs are also entering Svalbard waters.
These new species can compete – or consume – locally adapted Arctic species and change the community structure. The same is likely true for smaller organisms, although this is less well documented.
Initially, biodiversity as measured by the number of species present, will likely increase because the existing species are still present while new species are moving in. It is uncertain, however, whether the native species can survive. We already see large changes to both the fish and invertebrate communities in west Svalbard fjords.
Is there data to surely predict the future of the marine environment?
Svalbard is probably the best studied high Arctic environment. Many countries have field stations or at least a research presence here and they study everything, including land, ice, water and sediments.
In easily accessible areas like Isfjorden, Hornsund, Kongsfjorden, and even Rijpfjorden, the current systems are fairly well understood. Moored instruments and remote sensing provide very good coverage of ice and ocean conditions, both in the fjords and in surrounding waters.
Other Svalbard regions are less well understood due to less sampling. There are few measurements in the Arctic Ocean proper, although there is great interest in improving that situation. This requires considerable international collaboration, and the geopolitical situation with Russia is another large stumbling block to achieving a good understanding of the Arctic Ocean.
Is there reliable data to predict the future of the marine environment?
We are not able to make predictions with high accuracy about most components of the system. The best we can do now is a “what-if” scenario type of approach, like “what happens if/when king crabs invade Svalbard fjords? or “what is the effect of a 2 degree C rise in seawater temperature in Rijpfjorden?”.
For some of these questions we can try to model the situation and for others we can rely on studies of similar effects in other locations, but the biota and environmental conditions around Svalbard are unique to the area and it is not clear that data from other locations can be transferred there.
Does research in Svalbard help monitor Arctic Ocean changes?
Well, studying and monitoring changes is central to research in Svalbard. Coordination of these efforts is important and improved monitoring is recommended. The very high temperature changes observed in some Svalbard areas are among the highest documented.
One interesting and somewhat surprising result has been how variable the system can be. Amid the fastest warming in most records, we see several very cold and icy winters in a row. Sea ice in the last years is thicker in the Barents Sea and around Svalbard. It shows that change is not monotonous and is affected by other cycles and events at shorter and longer time scales. We have to keep this in mind when assessing change and attributing causes to that change.
What has surprised you most since you started these studies?
The speed of the change, followed closely by how little action this has resulted in from the regulators and policy makers.
We have one of the clearest examples of climate-change driven ecosystem modification at our doorstep and we have done surprisingly little as a nation and as a world. All the research we conduct cannot seem to move the world from making barely incremental changes despite the existential nature of the impacts we observe.
The ecosystem will adjust and exist in another state. It does not care whether humans are a part of that new system. So, it is up to us to do something about it.
What are the prospects for the Arctic Ocean?
I can only hope that we will wake up and do something to start to reduce/reverse the changes we are causing. Already there is virtually nothing to change the trajectory we are on by 2050 or 2060. We have to plan beyond that by starting to enact major changes now.
Regardless, Svalbard land and sea ecosystems are closely tied to conditions in the Arctic Ocean, so one could say that the Svalbard we know is at high risk of changing in a way that is difficult to predict, but likely substantial.
What is your message to visitors of Svalbard?
Bring back these experiences – and new understanding of the impacts of our actions – and share this news. Become activists for changing the way humans do business and move climate change to the top of the international to-do list.
Maybe in this way, a small place a thousand miles from the North Pole can be a catalyst for change around the world.
Last update: 11. March 2025