Scientists say warmer waters in the North Sea due to climate change have created conditions allowing jellyfish to thrive and reproduce.

Four reactor units at one of France’s largest nuclear power stations have been forced to shut down due to a swarm of jellyfish in the plant’s water pumping stations, French energy group Electricite de France (EDF) said.

Three reactor units were automatically shut down on Sunday evening at Gravelines on the English Channel, followed by the fourth early on Monday morning, EDF said, adding that the safety of the plant, its employees and the environment was not at risk.

“These shutdowns are the result of the massive and unpredictable presence of jellyfish in the filter drums of the pumping stations,” EDF said in a statement.

The plant in northern France is one of the largest in the country and is cooled from a canal connected to the North Sea.

Teams were carrying out inspections to restart the site “in complete safety”, EDF said, adding the reactors that were shut down are expected to restart on Thursday.

The beaches around Gravelines, between the major cities of Dunkirk and Calais, have seen an increase in jellyfish in recent years due to warming waters and the introduction of invasive species.

The Bulletin of the Atomic Scientists wrote in 2021 that jellyfish swarms incapacitating nuclear power plants is “neither new nor unknown” and there was substantial economic cost due to the forced closure of power plants.

Scientists are currently exploring ways to avert closures due to sea swarms, including using drones to map the movement of jellyfish, which would allow early intervention.

“Jellyfish breed faster when water is warmer, and because areas like the North Sea are becoming warmer, the reproductive window is getting wider and wider,” Derek Wright, marine biology consultant with the United States National Oceanic and Atmospheric Administration, told the Reuters news agency.

“Jellyfish can also hitch rides on tanker ships, entering the ships’ ballast tank in one port and often getting pumped out into waters halfway across the globe,” he said.

An invasive species known as the Asian Moon jellyfish, native to the Pacific Northwest, was first sighted in the North Sea in 2020. The species, which prefers still water with high levels of animal plankton, such as that in ports and canals, has caused similar problems before in ports and at nuclear plants in China, Japan, and India.

EDF said it did not know the species of jellyfish involved in the shutdown, but this is not the first time jellyfish have shut down a nuclear facility, though such incidents were “quite rare” – the last effect on EDF operations was in the 1990s.

There have been cases of plants in other countries shutting down due to jellyfish invasions, notably a three-day closure in Sweden in 2013 and a 1999 incident in Japan that caused a major drop in power output.

Experts say overfishing, plastic pollution and climate change have created conditions for jellyfish to thrive and reproduce.

EDF said there was no risk of a power shortage due to the shutdown, saying other energy sources, including solar power, were operational.

The US and China have extended their trade truce until 10 November, just hours before a jump in tariffs had been set to take effect.

In a joint statement, the world’s two biggest economies said triple-digit tariffs on each other’s goods announced earlier this year will be suspended for another 90 days.

Talks last month ended with both sides calling the discussions “constructive”. China’s top negotiator said at the time that the two countries would push to preserve the truce, while US officials said they were waiting for final sign-off from US President Donald Trump.

On Monday, Trump signed an executive order to extend the tariff truce.

It means Washington will further delay imposing 145% tariffs on Chinese goods and Beijing will continue its pause on 125% duties on US shipments.

Under the agreement, the US will hold its tariffs on Chinese imports at 30%, while China will keep a 10% tariff on American goods.

The truce extension will give more time for negotiations about “remedying trade imbalances” and “unfair trade practices”, the White House said.

It cited a trade deficit of nearly $300bn (£223bn) with China in 2024 – the largest among any of its trading partner.

The talks will also aim to increase access for US exporters to China and address national security and economic issues, the statement said.

A spokesperson for the Chinese embassy in Washington said: “Win-win cooperation between China and the United States is the right path; suppression and containment will lead nowhere.”

In the statement, China also called on the US to lift its “unreasonable” trade restrictions, work together to benefit companies on both sides and maintain the stability of global semiconductor production.

A return of higher duties would have risked further trade turmoil and uncertainty amid worries about the effect of tariffs on prices and the economy.

Trade tensions between the US and China reached fever pitch in April, after Trump unveiled sweeping new tariffs on goods from countries around the world, with China facing some of the highest levies.

Beijing retaliated with tariffs of its own, sparking a tit-for-tat fight that saw tariffs soar into the triple digits and nearly shut down trade between the two countries.

The two sides had agreed to set aside some of those measures in May.

That agreement left Chinese goods entering the US facing an additional 30% tariff compared with the start of the year, with US goods facing a new 10% tariff in China.

The two sides remain in discussions about issues including access to China’s rare earths, its purchases of Russian oil, and US curbs on sales of advanced technology, including chips to China.

Trump recently relaxed some of those export restrictions, allowing firms such as AMD and Nvidia to resume sales of certain chips to firms in China in exchange for sharing 15% of their revenues with the US government.

The US is also pushing for the spin-off of TikTok from its Chinese owner ByteDance, a move that has been opposed by Beijing.

Earlier on Monday in remarks to reporters, Trump did not commit to extending the truce but said dealings had been going “nicely”. A day earlier he called on Beijing to increase its purchases of US soybeans.

Even with the truce, trade flows between the countries have been hit this year, with US government figures showing US imports of Chinese goods in June cut nearly in half compared with June 2024.

In the first six months of the year, the US imported $165bn (£130bn) worth of goods from China, down by about 15% from the same time last year. American exports to China fell roughly 20% year-on-year for the same period.

Cannabis stocks soar after US president says he is ‘looking at’ reclassification.

United States President Donald Trump has said his administration is “looking at” reclassifying cannabis as a less dangerous drug.

Speaking to reporters at the White House on Monday, Trump said he would make a determination on the legal classification of the drug over the next few weeks.

“That determination hopefully will be the right one,” Trump said. “It’s a very complicated subject.”

Trump said that while he had heard “great things” about medical-use cannabis, he had heard bad things about “just about everything else” to do with the drug.

“Some people like it, some people hate it,” he said. “Some people hate the whole concept of marijuana because if it does bad for the children, it does bad for people that are older than children.”

Stocks in cannabis-related businesses soared following Trump’s remarks.

New York-based Tilray Brands jumped nearly 42 percent, with Canada’s Village Farms International and Canopy Growth Corp closing up about 34 percent and 26 percent, respectively.

Trump made his comments after The Wall Street Journal reported last week that he told attendees at a recent fundraising dinner that he was interested in reclassifying the drug.

While cannabis is fully legal, including for recreational use, in 24 US states, the use and possession of the drug is illegal at the federal level.

Cannabis is currently classified as a Schedule I drug, putting it in the same category as heroin, LSD and ecstasy.

Under the Drug Enforcement Administration’s classification system, Schedule I drugs are defined as those with “no currently accepted medical use and a high potential for abuse”.

Former US President Joe Biden proposed reclassifying cannabis as a Schedule III drug – defined as those with a “moderate to low potential for physical and psychological dependence” – but failed to enact the change before leaving office in January.