Did you know that there are forests in the Arctic?

Lush underwater forests of large brown seaweeds (kelps) are particularly striking in the Arctic, especially in contrast to the land where ice scour (scraping of sea ice against the sea floor) and harsh climates leave the ground barren with little vegetation.

Kelp forests have been observed throughout the Arctic by Inuit, researchers and polar explorers. The Canadian Arctic alone represents 10 per cent of the world’s coastlines, but we know little of the hidden kelp forests there.

Today, climate change is altering marine habitats such as kelp forests on a global scale. In western Australia, eastern Canada, southern Europe, northern California and eastern United States, kelps are disappearing due to warming temperatures. In other areas, kelps are being heavily over-grazed by sea urchins. Coastal conditions in the Arctic are changing dramatically and the region is warming faster than the rest of the world, but these changes could actually be good for kelp.

Yet we know little about kelp forests in remote Arctic regions. Our latest research, published in Global Change Biology, uncovers the distribution of Arctic kelp forests and explores how these important ecosystems are changing with the climate.

Antarctic Explorers: the new age of exploration in pictures Show all 20 1 /20 Antarctic Explorers: the new age of exploration in pictures Antarctic Explorers: the new age of exploration in pictures A Twin Otter airplane during a reconnaissance flight over the Antarctic Plateau and the Edson Glacier in the Ellsworth Mountains. This utility airplane, equipped with wheels or skis, adapts perfectly to the Antarctic environment with its rugged construction and short take off and landing performance EPA Antarctic Explorers: the new age of exploration in pictures Military personnel move drums with kerosene for the airplanes during their daily maintenance activities EPA Antarctic Explorers: the new age of exploration in pictures An explorer points the way to follow during a reconnaissance trip on the Edson Glacier, in the Ellsworth Mountains. The group moves in a straight line to minimize the risk of falling into hidden crevasse EPA Antarctic Explorers: the new age of exploration in pictures A member of INACH, Pablo Espinoza, lays in his sleeping bag in the Glaciar Union camp. The temperature inside the living tents averages minus five degrees Celsius EPA Antarctic Explorers: the new age of exploration in pictures An aerial view of the Glaciar Union camp in the Ellsworth Mountains. The Glaciar Union camp is a Chilean polar station operated by Chilean Antarctic Institute (INACH) and the three groups of the Armed Forces of Chile marking the beginning of all scientific activities planned in Antarctica for the summer season EPA Antarctic Explorers: the new age of exploration in pictures Two medics treat an injured soldier in the small station hospital in Glaciar Union camp. The most common cases are minor work injuries, frostbite and hypothermia EPA Antarctic Explorers: the new age of exploration in pictures A man walks through the Glaciar Union camp during a windstorm. Catabatic winds can reach up to 300 km/h and drop the thermal sensation to dangerous levels EPA Antarctic Explorers: the new age of exploration in pictures Members of the expedition who hadn't crossed the Antarctic Circle (a parallel 66.5 degrees south of the equator) enjoy a 'snow baptism' by other veterans EPA Antarctic Explorers: the new age of exploration in pictures A pilot of the Chilean Air Force tries to get signal on his satellite phone after landing on the Antarctic Plateau. Satellite communications is the only mean to keep in touch with the main operational base situated in Punta Arenas EPA Antarctic Explorers: the new age of exploration in pictures Scientist Ricardo Jana leaves a mobile station for a GPS tracking field trip in the Glaciar Union camp. Location tracking tools like the Differential Global Positioning System (DGPS) help to improve the safety on field trips by locating hidden crevasses in exact way EPA Antarctic Explorers: the new age of exploration in pictures A group of explorers extract blue ice blocks near the Glaciar Union camp. The ice will be used by scientists to keep their samples refrigerated EPA Antarctic Explorers: the new age of exploration in pictures An explorer helps himself to a dessert of fruit and yoghurt during lunch time in a communal area that also works as the kitchen, in the camp EPA Antarctic Explorers: the new age of exploration in pictures A group of scientists and explorers move on ski randonee to a sample spot on the Higgins Nunatak, in the Ellsworth Mountains. Snowmobiles, ski randonnee and short flights in Twin Otter airplanes are the most used travel options in field trips with scientists EPA Antarctic Explorers: the new age of exploration in pictures A man walks out of buried living unit in the Glaciar Union camp. Snow accumulation occurs mostly by wind displacement rather than snowfall EPA Antarctic Explorers: the new age of exploration in pictures Pablo Espinoza, gets ready for a field trip in his tent EPA Antarctic Explorers: the new age of exploration in pictures Scientists and military personnel play football in Glaciar Union camp EPA Antarctic Explorers: the new age of exploration in pictures Military personnel shovel dirty snow into an empty drum during a cleaning activity around the camp. Known as the 'chicken walk' the military personnel collect with shovels or by hand small debris or small patches of contaminated snow that can be found in the camp area. The expeditioners aim for a zero impact stay in this region EPA Antarctic Explorers: the new age of exploration in pictures A group of explorers transport scientists and material on snowmobiles during a field trip near Rossman Cove EPA Antarctic Explorers: the new age of exploration in pictures A member of INACH, Rene Quinan, in his tent. Up to three people can sleep in these clam tents designed for extreme weather conditions EPA Antarctic Explorers: the new age of exploration in pictures A group of explorers during a reconnaissance trip on ski randonee on the Edson Glacier EPA

Proliferation of kelps in the Arctic

Kelps currently occur on rocky coasts throughout the Arctic. The longest kelp recorded in the Arctic in Canada was 15 metres, and the deepest was found at 60-metre depth (Disko Bay, Greenland). Many find it surprising that marine plants can grow so well in harsh Arctic environments.

Kelps have adapted to the severe conditions. These cool water species have special strategies to survive freezing temperatures and long periods of darkness, and even grow under sea ice. In regions with cold, nutrient-rich water, they can attain some of the highest rates of primary production of any natural ecosystem on Earth.

Kelps function underwater in the same way trees do on land. They create habitat and modify the physical environment by shading light and softening waves. The underwater forests that kelps create are used by many animals for shelter and food. More than 350 different species — up to 100,000 small invertebrates — can live on a single kelp plant, and many fish, birds and mammals depend on the whole forest. Kelp forests also help protect coastlines by decreasing the power of waves during storms and reducing coastal erosion. A lot of kelp break off or are dislodged from the rock they attach to and end up in nearby habitats where they fuel deep food webs.

Changing climates, forests

As waters warm and sea ice retreats, more light will reach the sea floor, which will benefit marine plants. Researchers predict a northern shift of kelp forests as ice retreats.

Genetic evidence reveals that most kelps reinvaded the Arctic from the Atlantic Ocean quite recently (approximately 8,000 years ago, following the last Ice Age). As a result, most kelps in the Arctic are living in waters colder than their optimal temperature. Ocean warming will also move conditions closer to temperatures of maximum growth, and could increase the productivity of these habitats.

However, other changes are happening in the Arctic that complicate this picture. In Canada, Alaska, Greenland, Norway and Siberia, permafrost soils that have been frozen for thousands of years are receding by half a metre per year. Thawing permafrost and crumbling Arctic coasts are dumping sediments into coastal waters at alarming rates, which blocks light and could limit plant growth. The run-off from melting glaciers will also lower salinity and increase turbidity, which impacts young kelp.

Understanding kelp forests

The Canadian Arctic is the longest Arctic coastline in the world. The earliest scientific records of kelp in the Arctic are from Canada during expeditions in search of the Northwest Passage. In Hudson Bay and eastern Canada, kelp forests have been scientifically documented between Ellesmere Island and Labrador, and along coasts in Lancaster Sound, Ungava Bay, Hudson Bay, Baffin Bay and Resolute Bay.

In the northwestern Canadian Arctic, lack of rock substrate and a harsher climate support smaller, fragmented kelp forests. However, baseline measures of the extent of kelp communities are missing in many areas. Unfortunately, lack of information has already made it difficult to tell how kelp forests are changing.

Today, a number of researchers in Canada have partnered with northern communities and organisations to study kelp in the Arctic. The five-year ArcticKelp Project, for example, explores future changes and opportunities these ecosystems could provide. At the same time new technology (underwater lasers) is being developed in collaboration with Inuit fishers to map kelp forests in the Arctic. This is important, because knowledge on Arctic kelp forests could help northern communities and societies anticipate and benefit from these valuable changing ecosystems.

Forest potential

Kelp forests throughout the world play an important role in coastal economies, supporting a broad range of tourism, recreational and commercial activities. Kelp is making its way onto the plates of North Americans, and the kelp aquaculture industry is growing at a rate of seven per cent per year for the last 20 years globally (kelp is a coveted food source in many countries, full of potassium, iron, calcium, fibre and iodine). In the Arctic, Inuit traditionally use kelp as food and wild harvest numerous species.

Arctic kelp forests provide a key example of the diverse responses to climate change. Predictive models and experiments suggest that Arctic coasts are in line to become one of the most impacted environments in the world under changing climate. Yet the possible expansion of kelp forests should provide new habitats for fish and other marine organisms, and enhance a suite of valuable ecosystem services along Arctic coastlines.

This expanding resource may provide needed income to northern communities whose livelihoods are threatened by climate change and other impacts. Anticipating these changes and understanding these new ecosystems will be a key priority for Arctic nations. Just because you cannot see the forests growing in the Arctic does not mean we should not appreciate them and recognise the crucial role they play in the ocean.

Karen Filbee-Dexter receives funding from Natural Sciences and Engineering Research Council, the Australian Research Council, and the Norwegian Research Council. This article first appeared on The Conversation.