Image credit: Conor McDonnell.

Plastic pollution discovered on ice floes near the North Pole

Scientists on an expedition led by polar explorer Pen Hadow have discovered plastic pollution lying on remote frozen ice floes in the middle of the Arctic Ocean.

The discovery shows how far plastic pollution has spread, prompting fears that new plastic waste is flowing into the Arctic as the ice melts due to climate change. The thaw is also releasing plastic pollution long trapped in the frozen ice into the Arctic environment.

A team of scientists led by marine biologist Tim Gordon of the University of Exeter carried out research on two sailing boats as part of acclaimed polar explorer Pen Hadow’s ‘Arctic Mission’. Hadow is the only person to have trekked solo, without resupply, from Canada to the Geographic North Pole.

The pioneering expedition went further into the international waters of the Central Arctic Ocean than any other yachts in history, which was made possible because of recent reductions in summer ice cover in the Arctic. Rates of ice melt have increased dramatically due to climate change, with 40% of the Central Arctic Ocean now navigable in summer months.

Unlike conventional icebreaker research ships, the yachts navigated in narrow naturally-formed channels between ice floes to access habitats with minimal disturbance. Gliding through the water in relative silence, without the loud engines of large ships, reduced their levels of disruption to wildlife.

The Arctic Mission team was surprised to discover blocks of polystyrene in areas that are many hundreds of miles from land and were until recently covered by ice all year round. Two large pieces were spotted on the edge of ice floes between 77 and 80*N, in the middle of the international waters of the Central Arctic Ocean, within 1,000 miles of the North Pole.

Large plastic pieces such as this can break down into ‘microplastics’ - tiny particles of plastic that are accidentally consumed by filter-feeding animals. The plastic particles can stay in animals’ bodies and are passed up the food chain, threatening wildlife at all levels from zooplankton to apex predators such as polar bears.

Explorer Pen Hadow said he had never seen blocks of plastic waste before on the Arctic sea ice: “For the 25 years I have been exploring the Arctic I have never seen such large and very visible items of rubbish,” he said. “The blocks of polystyrene were just sitting on top of the ice.”

Tim Gordon added: “Finding pieces of rubbish like this is a worrying sign that melting ice may be allowing high levels of pollution to drift into these areas. This is potentially very dangerous for the Arctic’s wildlife.” >

The team will now test samples of Arctic seawater, collected during their pioneering voyage, for ‘microplastics’ – tiny particles of plastic less than 5 mm in size. They will assess whether microplastics are being released from the ice as its melts, and measure the extent of plastic pollution in the Arctic Ocean.

Estimates suggest there are over 5 trillion pieces of plastic floating on the ocean surface. It has been suggested there is now enough plastic to form a permanent layer in the fossil record.

Dr Ceri Lewis, scientific adviser to the expedition based at the University of Exeter, has previously warned that people produce around 300 million tons of plastic a year, which is roughly the same weight as all the humans on the planet. Around half of the plastic produced is used once and then thrown away.

Dr Lewis, senior lecturer in marine biology at the University of Exeter, who will be analysing the Arctic water samples for plastic said:  “Many rivers lead into the Arctic Ocean that are often a source of plastic pollution, but plastic pollution has been literally trapped into the ice. Now the ice is melting we believe microplastics are being released into the Arctic.  The Arctic is thought to be a hot spot of microplastics accumulation due to the number of rivers that empty into the Arctic basin, yet we have very little data to support this idea in the more northerly parts of the Arctic Ocean. This is really important data to collect as the Arctic supports many key fisheries which might be impacted but the presence of microplastics.”

The Arctic Mission team used nets with holes smaller than a millimetre across to look for microplastics in the environment. They will now analyse these samples in the laboratory to evaluate current levels of pollution in the Arctic and its likely impacts on wildlife. These baseline measurements will also be important in years to come to track changing pollution levels as the Arctic’s summer ice cover continues to retreat. All data will be comprehensively analysed before detailed findings are published in scientific journals over the next year.

The ‘Arctic Mission’ expedition represented an international collaboration of academics from the UK, USA, Norway and Hong Kong, conducting research on the impact of melting ice on the Arctic Ocean’s wildlife. The on-board scientific team, led by marine biologist Tim Gordon from the University of Exeter, carried out a multitude of tests to gauge emerging threats. The results of their investigations, and the study of samples taken, will help highlight emerging threats to a rapidly-melting Arctic Ocean, guiding future management strategies to protect polar wildlife.

Packed with scientific equipment, the yachts crossed thousands of miles of remote open sea, facing oceanic storms, close encounters with polar bears, and the perpetual threat of shifting ice floes trapping and crushing their yachts.

Gordon said: “Sailing into the Central Arctic Ocean has allowed us to study this ecosystem as never before. Without the usual disturbance of large ships’ roaring engines and ice-breaking hulls, we have gained unique insights into this special and rapidly-changing ecosystem.”

Some projections indicate that the entire Arctic Ocean will be ice-free in summer by 2050. This will allow human exploitation of the newly-opened waters, posing a range of new threats to Arctic wildlife.

Gordon added:  “The Arctic Ocean’s wildlife used to be protected by a layer of sea ice all year round. Now that is melting away, this environment will be exposed to commercial fishing, shipping and industry for the first time in history. We need to seriously consider how best to protect the Arctic’s animals from these new threats. By doing so, we will give them a fighting chance of adapting and responding to their rapidly-changing habitat.”

The team are also investigating the impact of man-made noise pollution on Arctic marine life and mammals, which can be particularly sensitive to sound. In a world where the sun doesn’t rise for months on end in winter and is blocked by ice cover at other times of the year, many animals rely on sound, rather than sight, for their daily lives.

The Arctic Mission team used underwater loudspeakers and microphones to understand how sound travels through the polar seas, and how this might be impacted by ice loss.

Arctic cod, beluga whales, ringed seals and walruses use a range of sounds to communicate in the underwater darkness. Narwhals hunt for fish a mile below the surface using bio-sonar, emitting 1000 high-pitched clicks every second and listening to their reflected echoes; much the same way that bats do.

Gordon warned that noise pollution due to the rapid growth in shipping and industry in the region could have serious consequences for these animals.

He said:  “Arctic animals that ‘see’ by sound are about to be blinded by noise. If commercial shipping routes open up across the top of the world, their roaring engines could drown out and even deafen acoustically-specialised polar animals, leaving them unable to function. By limiting shipping access to certain areas and using modern technology to reduce engine noise, we could stop this happening and protect the Arctic’s unique wildlife.”

Professor Steve Simpson, an expert in bioacoustics and noise pollution at the University of Exeter, who is supervising Gordon’s research, said:

"It is critical that we establish baseline natural recordings in this newly exposed oceanic environment. These recordings will allow us to understand how human activities are changing the soundscape of the summer Arctic, and assess the success of future noise management in this unique acoustic world.”

On-board wildlife biologist Heather Bauscher said: “The Arctic is a unique environment with a variety of extraordinary animals that rely on seasonal sea ice cover. Increasing ice melt and the opportunities that this facilitates for commercial activities in the region may have serious consequences for the whole ecosystem. Quality research along with the development of sound management strategies are necessary to protect the Arctic’s wildlife, this is crucial at a time of such dramatic change.”

Date: 25 September 2017