Icelanders have long joked that global warming was something people on the chilly Nordic island could look forward to, but as ice caps and glaciers melt at record speeds, that gag is wearing thin, according to the country’s president.

Warming oceans around the North Pole are harming biodiversity and fish stocks, and causing acidification in the world’s northern regions, forcing countries like Iceland to adapt to a new reality, said President Gudni Johannesson.

“The common joke in Iceland is to say that on this cold and windy, rain-swept island, global warming is something we should cheer for - but it’s no longer funny,” Johannesson told the Thomson Reuters Foundation in an interview.

“Climate change affects us all on this globe, but you can see the effects in particular in the northern regions - the ice cap around the North Pole is melting at record rates, the oceans there are getting warmer,” he said.

On the flip side, climate change could bring some economic benefits to the country of just 340,000 people, which would become a natural trade hub if new routes opened up from Asia to the Atlantic due to melting Arctic ice, he said.

“The fact that the ice cap in the north is melting is no source for joy (but) the undeniable fact is that where there was ice, there will be a free waterway,” he said. “Who knows, as the century goes on, maybe we will see increased traffic via the North Pole with Iceland as a hub.”

Johannesson was speaking on the sidelines of the World Ocean Summit in the Mexican resort of Playa del Carmen on Friday, where environmentalists, politicians and business leaders met to discuss how to improve the state of the oceans.

While warmer temperatures are driving greater stocks of mackerel towards Iceland’s coasts, the cod that was once a mainstay of its fishing industry is likely to head north, said Johannesson, who wore a pink tie made of cod skin at the summit.

Changing patterns of fish migration will make it essential to reach deals with neighbouring nations over fish catches, said the president, a former academic who has written about Iceland’s “cod wars”.

Iceland clashed with other states in the region several years ago as it upped the amount of mackerel it hauled in.

Iceland’s relations with places like the Faroe Islands and Norway are usually amicable, and “the only source of potential conflict lies in the distribution of fishing quotas”, Johannesson noted.

In 2016, mackerel was the third-largest catch for Iceland and its third most valuable fish, netting $103 million, or 8 percent of the nation’s total catch value.

Iceland is also weighing up how to expand its salmon-farming industry, while considering its potential environmental impact.

“Fish farming is a part of the blue economy now and… will expand,” said Johannesson. However, it has to be “as safe as possible because nature comes first”, he added.

As one of just a handful of countries in the world that permits commercial whale hunting, Iceland’s whale catch is “sustainable”, said Johannesson, who declined to comment on whether he personally supported the industry.

Whale-watching has boomed alongside the tourism that has underpinned Iceland’s economic rebound, he said, with no sign visitors are staying away in protest at Iceland’s continued hunting of minke and fin whales.

“Sustainability and the miniscule amount of whales being caught in recent years (are) based on scientific advice and way below any figures potentially threatening the future of the two whale stocks in question,” he said.