Three Bermudians who completed an Antarctic marathon said they had learnt first-hand about the effects of climate change on the frozen continent.

Mark Harris, Andy McComb and Phil Martin weathered rough seas and the risk of hypothermia to raise money for charity at the Antarctica Marathon last month.

Mr Harris, who returned to Bermuda last week, said that talks with scientists revealed how at risk the polar environment and the species that relied on it were.

He added: “The ecosystem is extremely fragile and we could all suffer if we don’t take action now.”

Mr Harris and his team, the Bermuda Penguins, ran the three-day marathon to raise money for Raleigh Bermuda, a youth adventure and education organisation.

The group of 82 runners were accompanied by a scientific team, including geologists and zoologists, who delivered lectures about Antarctica.

Mr Harris, a veteran marathon runner, said that he saw many species of birds and marine mammals such as seals and whales.

But he added that the scientists on board told them many of the species were close to extinction because of climate change.

Mr Harris said: “The expedition crew, who are regular visitors to the region with many of them staying at bases to conduct scientific studies, told us that they have seen major changes over the years.

“Glaciers were receding at an alarming rate and there were dramatic changes in penguin, seal and whale populations, putting all species at risk of extinction.”

He explained that rising sea levels caused by glacier melts affected animal and bird populations in the region.

Mr Harris added that plastic pollution that had drifted to the area and overfishing of krill, the main food source for whales and other sea life, had caused severe damage to fragile ecosystems.

He said the runners experienced the effects of the warming weather during the marathon.

Mr Harris explained that, even though it was summertime in the southern hemisphere, they expected to face unpredictable weather and temperatures as low as -45.5C, or -50F.

But he admitted, the team saw “some of the most favourable weather conditions” the marathon had experienced in years.

Mr Harris said: “We were extremely lucky with the weather — we had bright skies and low winds.

“The temperature was around freezing, but with the low wind there was very little wind chill.

“The clouds did come over a little bit during the run, but we were lucky in that the weather did not turn for the worst during the day, which it has been known to do.”

But Mr Harris said the warmer weather increased the risk of hypothermia for the runners.

He explained that the many layers of clothing worn at the start of the race caused runners to sweat more, which froze and put them at risk of a lowered body temperature.

Mr Harris said: “It was a balancing act. As runners who have trained only in warmer climes in Bermuda, we were particularly vulnerable to the cold.

“When all the runners had finished their race, it was key to get warm layers on quickly and avoid standing around with just your running gear.”

The marathon participants met in Argentina in mid-January, flew to Buenos Aires and sailed across Drake’s Passage to Antarctica.

About 23 runners had to drop out of the race because they contracted Covid-19 or had been in contact with an infected individual.

Anna Laura Hocking, another Bermudian, was forced to sit out the race after tested positive for Covid-19 when she arrived in Antarctica.

Ms Hocking said that her time in isolation on the ship was a “mental marathon” that involved staying entertained with minimal contact with others or the internet.

She explained: “There was no TV, a few movies and I had one book.

“I had no space to exercise, therefore there was no opportunity for me to run a marathon in my cabin, as some suggested.

“The saving grace was the fact I had a balcony and the ship often moved locations. I witnessed some of the very best of what Mother Nature has to offer.”

Ms Hocking pledged to attempt the Antarctica Marathon again next year.