Disappearing Sea Ice Is Changing The Whole Ecosystem Of The Arctic Ocean

Disappearing Sea Ice Is Changing The Whole Ecosystem Of The Arctic Ocean outdoorsman / shutterstock

I drafted this while looking north over the frozen Lincoln Sea, at the northernmost tip of Ellesmere Island in Canada. I was at Alert, a Canadian Forces Station which, at 82°N, is the most northerly permanently inhabited place on Earth. Just 815km away, across the Arctic Ocean, lay the North Pole.

It was May, and the sea should have still been frozen, but this year the bridge of sea ice between Ellesmere and Greenland broke up early, and Arctic ice began flowing down the narrow Nares Channel and south into Baffin Bay. All across the Arctic Ocean, the amount and persistence of sea ice is declining – September ice cover has fallen around 30% since 1980.

Disappearing Sea Ice Is Changing The Whole Ecosystem Of The Arctic Ocean Alert (red dot) is at the northern end of Canada’s most northerly island. NASA/Goddard Space Flight Center

The Arctic is warming at twice the rate of the rest of the planet, and images of polar bears on small ice floes capture the imagination. But those images represent (excusing the pun) only the tip of the iceberg – the consequences of ice loss are profound and start from the very bottom of the food chain, in the microbial processes that drive the biology of the ocean.

Arctic food chains sometimes start in sea ice

Sea ice forms when seawater temperature falls below -1.8℃. As the ice crystals form, salt is forced out and ice brines and other dissolved constituents become trapped in a honeycomb of small channels in the ice. Cold salty water draining from the ice also sinks deep to the bottom of the oceans and drives water circulation across the globe.

As the air grows colder, the ice thickens downwards and, in the brine channels and across the ice bottom, specialised algae and bacteria grow. When sunlight returns to the Arctic in the spring and penetrates through the ice (which is rarely more than a few metres thick) these ice-algal communities start to photosynthesise, producing algal biomass and abundant dissolved organic matter.

Disappearing Sea Ice Is Changing The Whole Ecosystem Of The Arctic Ocean Ice algae growing on the bottom of an ice core. Graham Underwood, Author provided

This feeds a wide range of microscopic creatures known as zooplankton, which graze across the bottom of the ice. These zooplankton in turn feed larger animals and drive the food chain throughout spring.

When the ice melts more of this material flows out into the seas, providing more food resources at the bottom of food chains. In a recent study published in Nature Climate Change, colleagues and I showed how the different components of this organic matter derived from ice-algae are used by different species of bacteria and at different rates in underlying seawater, so that more melting ice will change the patterns of organic matter turnover in surface waters during spring.

Disappearing Sea Ice Is Changing The Whole Ecosystem Of The Arctic Ocean Ice-algae diatoms, right at the bottom of the Arctic food chain. Graham Underwood, Author provided

Different food chains may develop

Not all sea ice melts each summer – or at least it didn’t. Multi-year ice can go through a number of years of melting and growing, getting thicker and more structurally complex. But, over time, this multi-year ice has become rarer. In the 1980s, around one-third of the Arctic’s ice cover was more than four years old – today, such ice is almost nonexistent. Instead, more first-year ice will form and completely melt each year, providing new food inputs into areas of ocean that were previously permanently covered in ice.

This has significant consequences. Less ice cover in summer means more open ocean water, which – as it is darker – absorbs more sunlight and heat, making it harder to freeze in the autumn. Open water also means the wind can stir up the sea and slow the process of refreezing. More open water in summer will change the plankton communities, and then the animals that feed on them.

Some species are moving north. Already the Barents Sea between Norway and Svalbard is now rarely covered in ice in winter – and North Atlantic species such as cod and top predators such as orca are moving in. Specialist species that rely on ice such as polar bears, ringed seals, walrus and Arctic cod are losing their habitats, while non-indigenous species are expanding their range.

Disappearing Sea Ice Is Changing The Whole Ecosystem Of The Arctic Ocean The author, at 82ºN. Graham Underwood, Author provided

For some, a warmer Arctic brings opportunities. Reduced ice cover means ships can use the north-east and north-west passages, significantly shortening journey times between the Atlantic and the Pacific. New fisheries may develop, and less ice means access to oil and gas resources becomes possible.

But these benefits to some, come at potentially huge costs. In addition to the changes in the ocean, a warmer Arctic could disrupt ocean circulation and global weather systems, while permafrost will continue to thaw, potentially releasing greenhouse gases currently locked up in frozen soils.

A whole ecosystem, rich in specialist species – many barely studied – is changing before our eyes. The Arctic is a beautiful and harsh place, posing serious logistical challenges for scientific investigation. But even there, on the top of the world, far from centres of human population, our impact is evident.

About The Author

Graham J. C. Underwood, Professor of Marine and Freshwater Biology, University of Essex

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Related Books

Life After Carbon: The Next Global Transformation of Cities

by Peter Plastrik , John Cleveland
1610918495The future of our cities is not what it used to be. The modern-city model that took hold globally in the twentieth century has outlived its usefulness. It cannot solve the problems it helped to create—especially global warming. Fortunately, a new model for urban development is emerging in cities to aggressively tackle the realities of climate change. It transforms the way cities design and use physical space, generate economic wealth, consume and dispose of resources, exploit and sustain the natural ecosystems, and prepare for the future. Available On Amazon

The Sixth Extinction: An Unnatural History

by Elizabeth Kolbert
1250062187Over the last half-billion years, there have been Five mass extinctions, when the diversity of life on earth suddenly and dramatically contracted. Scientists around the world are currently monitoring the sixth extinction, predicted to be the most devastating extinction event since the asteroid impact that wiped out the dinosaurs. This time around, the cataclysm is us. In prose that is at once frank, entertaining, and deeply informed, New Yorker writer Elizabeth Kolbert tells us why and how human beings have altered life on the planet in a way no species has before. Interweaving research in half a dozen disciplines, descriptions of the fascinating species that have already been lost, and the history of extinction as a concept, Kolbert provides a moving and comprehensive account of the disappearances occurring before our very eyes. She shows that the sixth extinction is likely to be mankind's most lasting legacy, compelling us to rethink the fundamental question of what it means to be human. Available On Amazon

Climate Wars: The Fight for Survival as the World Overheats

by Gwynne Dyer
1851687181Waves of climate refugees. Dozens of failed states. All-out war. From one of the world’s great geopolitical analysts comes a terrifying glimpse of the strategic realities of the near future, when climate change drives the world’s powers towards the cut-throat politics of survival. Prescient and unflinching, Climate Wars will be one of the most important books of the coming years. Read it and find out what we’re heading for. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

enafarzh-CNzh-TWdanltlfifrdeiwhihuiditjakomsnofaplptruesswsvthtrukurvi

follow InnerSelf on

facebook-icontwitter-iconrss-icon

 Get The Latest By Email

{emailcloak=off}

LATEST VIDEOS

How These Three Financial Firms Could Change The Direction Of The Climate Crisis
How These Three Financial Firms Could Change The Direction Of The Climate Crisis
by Mangulina Jan Fichtner, et al
A silent revolution is happening in investing. It is a paradigm shift that will have a profound impact on corporations,…
PBS Nova's Polar Extremes
PBS Nova's Polar Extremes
by PBS
In this two-hour special, renowned paleontologist Kirk Johnson takes us on an epic adventure through time at the polar…
A huge iceberg just broke off West Antarctica’s most endangered glacier
A Huge Iceberg Just Broke Off West Antarctica’s Most Endangered Glacier
by Madeleine Stone
Huge blocks of ice regularly shear away from Antarctica’s ice shelves, but the losses are speeding up.
The Rise Of Solar Power
by CNBC
Solar power is on the rise. You can see the evidence on rooftops and in the desert, where utility-scale solar plants…
World's Largest Batteries: Pumped Storage
by Practical Engineering
The vast majority of our grid-scale storage of electricity uses this clever method.
Hydrogen Fuels Rockets, But What About Power For Daily Life?
Hydrogen Fuels Rockets, But What About Power For Daily Life?
by Zhenguo Huang
Have you ever watched a space shuttle launch? The fuel used to thrust these enormous structures away from Earth’s…
Fossil Fuel Production Plans Could Push Earth off a Climate Cliff
by The Real News Network
The United Nations is beginning its climate summit in Madrid.
Big Rail Spends More on Denying Climate Change than Big Oil
by The Real News Network
A new study concludes that rail is the industry that's injected the most money into climate change denial propaganda…

LATEST ARTICLES

Why Australian Labor’s Climate Policy Is Too Little, Too Late
Why Australian Labor’s Climate Policy Is Too Little, Too Late
by Will Steffen
Opposition leader Anthony Albanese’s announcement on Friday that a Labor government would adopt a target of net-zero…
How These Three Financial Firms Could Change The Direction Of The Climate Crisis
How These Three Financial Firms Could Change The Direction Of The Climate Crisis
by Mangulina Jan Fichtner, et al
A silent revolution is happening in investing. It is a paradigm shift that will have a profound impact on corporations,…
Green Ammonia Could Slash Emissions From Farming And Power Ships Of The Future
Green Ammonia Could Slash Emissions From Farming And Power Ships Of The Future
by Bill David
For the past 100 years, a simple molecule has had an immensely positive impact on our world. Ammonia, which comprises…
Ideal US Cities To Survive Climate Change
Ideal US Cities To Survive Climate Change
by Johnna Crider
Climate scientists have shared where they think would be an ideal place to live in the United States in order to avoid…
Stories Of When Your Kids Make You Feel Old! | The Curls
Old Conservative White Men: Pass The Football To Someone Who Will Try To Score
by Robert Jennings, InnerSelf.com
We have had important US elections but this one in November 2020 is undoubtedly the most important. Why? America and…
How Tiny Microbes Are Revolutionizing Big Agriculture
How Tiny Microbes Are Revolutionizing Big Agriculture
by Mathew Wallenstein, Colorado State University
Walk into your typical U.S. or U.K. grocery store and feast your eyes on an amazing bounty of fresh and processed…
Uk’s Nuclear Future Hangs On Electricity Tax
Uk’s Nuclear Future Hangs On Electricity Tax
by Paul Brown
The new British prime minister, Boris Johnson, must soon decide whether to save the UK’s nuclear future with an…
Extreme Weather Could Push The U.S. Into Recession
Extreme Weather Could Push The U.S. Into Recession
by Karen Nikos
Physical climate risk from extreme weather events remains unaccounted for in financial markets, a new paper warns.