Former US President Joe Biden recently underwent skin cancer surgery, his spokeswoman said.

Biden had Mohs surgery, she told the BBC’s US partner CBS News, but did not immediately provide further details.

The procedure is used to cut away skin until no evidence of cancer remains.

The 82-year-old had been spotted with a wound on the right side of his head in recent days.

In 2023, Biden had a cancerous skin lesion removed from his chest during a routine health screening.

In May, he was diagnosed with an aggressive form of prostate cancer that has spread to his bones.

“Cancer touches us all,” Biden wrote on social media at the time. “Like so many of you, Jill and I have learned that we are strongest in the broken places.”

Biden also had several non-melanoma skin cancers removed in the past, before he became president.

He has largely retreated from the public eye since leaving the White House in January and has made few public appearances.

The Bidens have long been strong advocates for fighting and curing cancer. Their adult son, Beau, died in 2015 from brain cancer.

Working from a dock on St. Helena Island, S.C., on a sweltering day this summer, Ed Atkins pulled in a five-foot cast net from the water and dumped out a few glossy white shrimp from the salt marsh.

Mr. Atkins, a Gullah Geechee fisherman, sells live bait to anglers in a shop his parents opened in 1957. “When they passed, they made sure I tapped into it and keep it going,” he said. “I’ve been doing it myself now for 40 years.”

These marshes, which underpin Mr. Atkins’s way of life, are where the line between land and sea blurs. They provide a crucial nursery habitat for many marine species, including commercial and recreational fisheries.

But these vast, seemingly timeless seascapes have become some of the world’s most vulnerable marine habitats, according to a new study published on Thursday in the journal Science that adds up and maps the ways human activity is profoundly reshaping oceans and coastlines around the world.

Soon, many of Earth’s marine ecosystems could be fundamentally and forever altered if pressures like climate change, overfishing, ocean acidification and coastal development continue unabated, according to the authors.

It’s “death by a thousand cuts,” said Ben Halpern, a marine biologist and ecologist at the University of California, Santa Barbara, and one of the authors of the new study. “It’s going to be a less rich community of species. And it may not be something we recognize.”

Among the other ecosystems at high risk are sea grass meadows, rocky intertidal zones and mangrove forests. These parts of the ocean, near shore, are the ones people most depend on. They provide natural defenses against storm damage. And the vast majority of commercial and recreational fishing, which together support more than two million jobs in the United States alone, takes place in shallower coastal waters.

There’s also an intangible cultural richness at stake. The culture of Gullah Geechee people like Mr. Atkins, a community descended from enslaved West Africans forced to work the rice and cotton plantations of the Southeastern coast, for example, is inextricably linked to fishing and the seashore.

“We have our own language, we have our own food ways, we have our own ecological system here,” said Marquetta Goodwine, the elected head of the Gullah Geechee people and a leader in efforts to protect and restore the coastline. That distinctive culture, she said, depends on things like the oyster beds, the native grasses and the maritime forests that characterize the seashore and the scores of tidal and barrier islands here, collectively known as the Sea Islands.

“You don’t have that, you don’t have a Sea Island,” said Ms. Goodwine, who also goes by Queen Quet. “You don’t have a Sea Island, you don’t have Gullah Geechee culture.”

A Poorer Ocean

The new study tries to measure just how much various human-caused pressures are squeezing, shifting and transforming coastal and marine habitats.

The research began in the early 2000s, when widespread coral bleaching was raising alarm among marine scientists. In response, Dr. Halpern and his colleagues set out to map the parts of the ocean that were healthiest and least affected by humans and, conversely, which parts were the most affected.

The inherent challenge was comparing marine habitats, from coral reefs to the deep ocean floor, and their responses to different human activities and pressures, like fishing and rising temperatures, all on a common scale. They came up with what researchers call an impact score that’s based on a formula incorporating the location of each habitat, the intensities of the various pressures on that habitat, and the vulnerabilities of each habitat to each form of pressure.

Under the world’s current trajectory, the study found, by the middle of the century about 3 percent of the total global ocean is at risk of changing beyond recognition. In the nearshore ocean, which most people are more familiar with, the number rises to more than 12 percent.

That future will look different in different regions. Tropical and polar seas are expected to face more pronounced effects than temperate, mid-latitude ones. Human pressures are expected to increase faster in offshore zones, but coastal waters will continue to experience the most serious effects, the researchers forecast.

There are also countries that are considered more vulnerable because they depend more heavily on resources from the ocean: Togo, Ghana and Sri Lanka top the list in the study.

Across the whole ocean, scientists generally agree that many places will look ecologically poorer, with less biodiversity, Dr. Halpern said. That’s mainly because the number of species that are resilient against climate change and other human pressures is simply far fewer than the number of more vulnerable species.

The study found that the biggest pressures, both now and in the future, are ocean warming and overfishing. But the researchers most likely underestimated the effects of fishing, they wrote, because their model assumes that fishing activity will hold steady rather than increase. They also focused only on the species actually targeted by fishing fleets and did not include by-catch, the unwanted species swept up in gear like gill nets and discarded, or habitat destruction from bottom trawling.

The effects of some other human activities aren’t well represented either, including seabed drilling and mining, which are expanding quickly offshore.

Another limitation of the Science study is the fact that the researchers simply added together the pressures from human activities in a linear way to arrive at their estimate of cumulative effects. In reality, those effects might add up to more than the sum of their parts.

“Some of these activities, they might be synergistic, they might be doubling,” said Mike Elliott, a marine biologist and emeritus professor at the University of Hull in England who was not involved in the study. “And some might be antagonistic, might be canceling.”

Even so, Dr. Elliott said he agreed with the broad conclusions of the new study. Scientists could argue about whether the cumulative effects of human activities will double or triple, he said, “but it will be more, because we’re doing more in the sea.”

“If we wait until we’ve got perfect data,” he added, “we’ll never do anything.”

‘Time to Scale It Up’

One of the benefits of such studies is that they can help inform better ocean planning and management, including initiatives like 30×30, the global effort to place 30 percent of the world’s land and seas under protection by 2030.

In South Carolina, one place that has already been set aside is the ACE Basin, a largely undeveloped 350,000-acre wetland on the state’s southern coast that is named for the Ashepoo, Combahee and Edisto rivers, which thread through it.

Riding a boat across the enormous basin can be disorienting. The world flattens as the sun beats down and salt marsh stretches in every direction. Almost everything is a vivid blue or green, like an abstract painting or a map come to life.

White wading birds dot the green marsh grasses, and occasional groups of gray bottlenose dolphins break the blue surface of the water.

Sometimes the dolphins corral their fish prey onto the mud and temporarily beach themselves for a meal, using the salt marsh islands like giant dinner plates. This behavior, called strand feeding, is rarely seen outside the Southeast.

On a recent visit, in one tucked-away corner of the marsh, something emerged from the mud at low tide: a wall, built with concrete blocks now nearly hidden by thousands of shells. They’re called oyster castles, and they look like something out of a storybook about mermaids.

The blocks were placed by volunteers from the Boeing assembly plant in nearby North Charleston. The effort was organized by the Nature Conservancy and the South Carolina Department of Natural Resources as part of a growing string of living shorelines projects, which aim to stabilize the coast using natural materials like shellfish and native vegetation, in South Carolina and beyond.

The oyster castles are meant to protect the landscapes behind them from erosion, sea level rise and storm surges. Scientists from the Nature Conservancy have been experimenting with a variety of methods for years, and are beginning to see results. Behind the oyster castles, which allow water to pass through and deposit sediment, mud had piled up significantly higher than elsewhere. And in the mud, marsh grass has taken root and grown tall.

“We’ve been testing and piloting things for so long, and now is the time to scale it up,” said Elizabeth Fly, director of resilience and ocean conservation at the Nature Conservancy’s South Carolina chapter.

In fact, the state’s oyster shell recycling program has now built small living shorelines at more than 200 sites, all with the help of volunteers, and often working with other groups, like the Gullah Geechee Nation. There’s a living shoreline taking shape at the Charleston wastewater treatment plant. Another at the entrance to the exclusive Kiawah Island Golf Resort. They’re at Marine Corps bases, at boat launches and at docks.

Many of these efforts are part of a sprawling network called the South Atlantic Salt Marsh Initiative, which includes the Pew Charitable Trusts, the Department of Defense, other federal agencies and state governments. The network spans one million acres of salt marsh across four Southeastern states.

Amid those efforts to reinforce and protect marine ecosystems, and as scientists work to better understand the pressures that are altering the oceans, people in coastal communities everywhere are already living changes large and small.

The day after Mr. Atkins demonstrated his fishing methods, the town of Mount Pleasant, S.C., 80 miles up the coast, held its annual Sweetgrass Festival to celebrate the region’s traditional Gullah Geechee baskets. Dozens of artists braved the heat in booths at a waterfront park, showing off and selling baskets woven from sweetgrass, bulrush, palmetto leaves and pine needles.

One artist and teacher, Henrietta Snype, displayed baskets made by five generations of her family, from her grandmother down to her own grandchildren.

Ms. Snype started making baskets at age 7. Now, at 73, she takes pride in upholding the tradition and teaching others the craft and its history. But she feels the world around her changing.

She said she had noticed the climate shifting for many years now. Big hurricanes seem to have become more frequent and seem to do more damage. And making baskets is harder, too.

Traditionally, the men in basket-making families went out into the dunes, marshes and woods to gather the materials they needed. But lately, Ms. Snype said, the plants have been harder to find. Sweetgrass is diminishing, and harvesters have trouble getting access to built-up and privately owned parts of the coastline.

“The times bring on a lot of change,” she said.

Goodwill messages continued this week’s unprecedented public display of diplomatic unity between Beijing, Pyongyang and Moscow.

North Korean leader Kim Jong Un told Chinese President Xi Jinping that North Korea will support China in protecting its sovereignty, territory and development interests, as the pair met just a day after an unprecedented show of unity with Russian President Vladimir Putin in Beijing.

The bilateral meeting between Xi and Kim on Thursday came as Russia also hailed North Korea’s role supporting its war in Ukraine, continuing the public display of close relations between Pyongyang, Beijing and Moscow after their meeting at Wednesday’s huge military parade in China’s capital to mark 80 years since the end of World War II.

In an article published on Friday by North Korea’s state-run outlet, the Korean Central News Agency (KCNA), Kim was quoted as saying, “No matter how the international situation changes, the feeling of friendship cannot change” between Pyongyang and Beijing.

“The DPRK [Democratic People’s Republic of Korea] will as ever invariably support and encourage the stand and efforts of the Communist Party of China and the government of the People’s Republic of China to defend the sovereignty, territorial integrity and development interests of the state,” Kim said after meeting with Xi, according to KCNA.

Xi also reportedly told Kim that China and North Korea are “good neighbours, good friends and good comrades” that share one destiny, and he was willing to “defend, consolidate and develop” the countries’ relations, KCNA said.

KCNA also confirmed that Kim departed Beijing on Thursday, concluding his first trip outside of North Korea since meeting with Putin in Russia in 2023.

Top-ranking Chinese Communist Party officials – including Cai Qi and Foreign Minister Wang Yi – attended a send-off ceremony for Kim, according to KCNA.

During Wednesday’s military parade in Beijing – in which the People’s Liberation Army displayed its latest generation of stealth fighters, tanks and ballistic missiles amid a highly choreographed cast of thousands – Xi hailed China’s victory 80 years ago over “Japanese aggression” in the “world anti-fascist war”.

Putin and Kim were among some 26 mostly non-Western world leaders in attendance, with the pair meeting with Xi for two and a half hours on the event’s sidelines in an unprecedented display of unity. The trio discussed “long-term” cooperation plans, according to KCNA.

Putin and Kim also met prior to the parade, with both leaders praising the deepening military partnership between Moscow and Pyongyang.

Seemingly rattled by the meeting, United States President Donald Trump addressed Xi in a post on his Truth Social platform, saying: “Please give my warmest regards to Vladimir Putin, and Kim Jong Un, as you conspire against The United States of America.”

A Kremlin aide dismissed Trump’s remarks, saying “no one even had this in their thoughts”.

Following the meeting, Putin also sent Kim a congratulatory message for North Korea’s foundation day, in which he hailed Pyongyang’s support for Moscow’s military campaign in Ukraine.

“Your combat force’s heroic involvement in liberating the Kursk territories from the invaders is a distinct symbol of friendship and mutual aid between Russia and North Korea,” Putin’s message read, according to KCNA.

“I am confident that we will continue to work together to consolidate the comprehensive strategic partnership between our two countries,” Putin added.

North Korea has controversially sent thousands of soldiers to fight in Kursk – a Russian region briefly occupied by Ukraine – and also provided artillery ammunition and missiles to support Moscow in its war against Kyiv.

During their meeting in Beijing, Kim also reportedly told Putin his country would “fully support” Russia’s army as a “fraternal duty”, KCNA previously reported.

Secretary of State Marco Rubio has said the US will “blow up” foreign crime groups if needed, possibly in collaboration with other countries.

“Now they’re gonna help us find these people and blow them up, if that’s what it takes,” Rubio said during a visit to Ecuador.

He also announced the US will designate two of Ecuador’s largest criminal gangs, Los Lobos and Los Choneros, as foreign terrorist organisations.

The comments come days after US forces carried out a strike on a boat in the Caribbean Sea. The White House says it killed 11 drug-traffickers, though it did not release their identities.

Asked whether smugglers coming from US allies, like Mexico and Ecuador, could face “unilateral execution” from US forces, Rubio said “co-operative governments” would help identify smugglers.

“The president has said he wants to wage war on these groups because they’ve been waging war on us for 30 years and no-one has responded.

“But there’s no need to do that in many cases with the friendly governments, because the friendly governments are going to help us.”

The Ecuadorian and Mexican governments have not said they would assist with military strikes.

In the wake of Tuesday’s strike on the vessel in the southern Caribbean, President Donald Trump said the military operation had targeted members of the Venezuelan gang Tren de Aragua as they transported illegal narcotics towards the US.

Legal experts told BBC Verify the strike may have violated international human rights and maritime law.

Late on Thursday, the defence department accused two Venezuelan military aircraft of flying near a US vessel in a “highly provocative move designed to interfere with our counter narco-terror operations”. Venezuela is yet to respond to the claim.

Also on Thursday, Rubio announced Washington would issue $13.5m (£10m) in security aid and $6m in drone technology to help Ecuador crack down on drug trafficking.

Violence in Ecuador has soared in recent years as criminal gangs battle for control over lucrative cocaine routes

According to government data, about 70% of the world’s cocaine now passes through Ecuador in transit from neighbouring producing countries, like Colombia and Peru, to markets in the US, Europe and Asia.

This designation was desired by the Ecuadorian President Daniel Noboa, who described his clampdown on criminal gangs as a “war.”

In an interview with the BBC earlier this year, he said he would be “glad” if the US considered Los Lobos and Los Choneros, as terrorist groups because “that’s what they really are”.

He also said he wanted US and European armies to join his fight.

Noboa is trying to change Ecuador’s constitution to allow foreign military bases in the country again – after the last US one was closed in 2009.

The designation means the US can target the assets and properties of anyone associated with the groups and share intelligence with the Ecuadorian government without limitations so it could take “potentially lethal” actions.

Soaring cartel violence in Ecuador has been a driver behind migration from the South American country to the US, too.

According to immigration law experts, it is unclear whether designating cartels as terrorist organisations may help or hinder their victims who seek asylum in the US.

On the one hand, it may mean they are now considered victims of “terrorism’, but on the other hand some fear those who have had to pay extortions to gangs could be penalised for ‘materially supporting’ them.