分类： science

In a remarkable and unexpected encounter that has marine biologists buzzing, a volunteer diver has shared unprecedented footage of an endangered great white shark spotted in the Mediterranean Sea, between the coastlines of Tunisia and Sicily. The diver, who asked not to be named, recalled experiencing intense shaking as he came face-to-face with the massive predator, an encounter that most divers only ever dream of. Great white sharks are rarely documented in this part of the Mediterranean, making the new footage a significant contribution to marine ecological research. Sightings of the species have dropped sharply across the globe in recent decades due to overfishing, habitat degradation, and accidental bycatch, leading to their classification as an endangered species by major conservation organizations. Marine researchers say this rare documentation offers a critical new clue about the species’ range and potential habitats in the Mediterranean, a body of water that has long been understudied when it comes to large predatory sharks. Conservation teams are now hopeful that this sighting will highlight the need for stronger protections for marine biodiversity in the region, and help scientists better understand how endangered shark populations are adapting to changing ocean conditions.

As climate change accelerates ocean warming and amplifies extreme weather events worldwide, and the Trump administration moves forward with deep cuts to a critical U.S. ocean observation program, the European Union is stepping into the gap with a €92 million ($107 million) investment to expand its international ocean monitoring network. Named OceanEye, the new initiative was announced Wednesday by European Commission President Ursula von der Leyen, who said the funding will position the EU at the forefront of global efforts to map and study Earth’s largely underexplored oceans.

Oceans cover more than 70% of the planet’s surface, underpinning global life systems by producing half the world’s oxygen and absorbing roughly 30% of human-caused carbon dioxide emissions. But decades of greenhouse gas emissions have pushed ocean temperatures to record highs, with warming accelerating faster in recent decades than at any point in modern recorded history. This warming has supercharged tropical cyclones, extended drought conditions, bleached and killed 50% of the world’s coral reefs, and pushed thousands of marine species toward extinction — threats compounded by overfishing and industrial ocean pollution. Scientific projections warn that climate change will continue to increase the intensity of heatwaves and severe storms across Europe in the coming decades, making accurate ocean data more critical than ever for disaster preparedness and mitigation.

Systematic, continuous ocean monitoring is the foundation of effective marine protection: it maps existing ecosystem damage, identifies emerging threats, and provides the empirical data needed to craft evidence-based regulations to halt biodiversity loss. “This is about using science and good governance to understand our ocean and secure our future,” von der Leyen emphasized in her announcement of the initiative.

The EU’s investment comes at a moment of growing gap in global ocean observation capacity. In May of this year, the Trump administration signaled plans to eliminate funding for the U.S. Ocean Observatories Initiative, a 10-year-old network of more than 900 fixed and mobile ocean sensors that cost $386 million to build. Funded by the U.S. National Science Foundation, the initiative has collected free, real-time ocean data on everything from circulation patterns to marine ecosystem shifts, climate change trends and extreme weather activity. That open-source data has supported more than 500 peer-reviewed scientific studies, and the project was originally scheduled to operate for another 15 to 20 years before the funding cuts were proposed.

Prior to the U.S. funding announcement, global ocean observation efforts were coordinated through the UN-affiliated Global Ocean Observing System, with the United States historically collecting more than half of all global ocean observation data, Europe contributing roughly 25%, and the remainder coming from Japan, Australia, India and China. EU officials and ocean scientists say the funding gap created by U.S. cuts makes increased European investment an urgent priority.

“Europe needs to do more,” explained Pierre-Yves Le Traon, oceanographer and scientific director of Toulouse-based Mercator Ocean International. Under the OceanEye plan, the EU has set an ambitious target to take responsibility for 35% of global ocean monitoring by 2035, and to become the world’s leading provider of standardized “ocean intelligence” data for researchers, governments and private industries.

Ocean observation data powers far more than just climate research. Data collected by underwater drones, robotic sensors and orbiting ocean-focused satellites is shared with shipping companies, commercial fisheries, emergency disaster response agencies, and research institutions. Mercator Ocean International is currently building the Digital Twin Ocean, a real-time interactive virtual reality replica of the world’s oceans that relies entirely on continuous observational input to model changes. Le Traon noted that this data is critical not just for climate adaptation, but for a wide range of coastal and maritime sectors including aquaculture, Arctic shipping, coastal tourism, agriculture, and even maritime security operations. “Knowledge is essential if we want to manage the ocean,” Le Traon said. “We really have to be very active for the monitoring and protecting of the ocean because the ocean matters to everyone: for life at sea, for life on Earth.”

Odran Corcoran, a policy advisor for the marine conservation non-profit Oceana, added that systematic observation is particularly critical to filling gaps in existing scientific knowledge that hold back effective policy. Only by collecting consistent data from the deep ocean — which remains one of the least understood environments on Earth — can lawmakers craft evidence-based regulations for sustainable fisheries management, marine protected area expansion, and marine ecosystem restoration projects. “Europe does not just need more ocean data; it needs data that closes biodiversity and seabed knowledge gaps,” Corcoran said.

Funding from the OceanEye initiative will go toward two core priorities: supporting private sector innovation incubators for ocean monitoring technology, and expanding the capacity of existing international coordination bodies including the Global Ocean Observing System. Of the EU’s 27 member states, 22 have coastal territories bordering the Baltic Sea, Atlantic Ocean, Black Sea and Mediterranean Sea. France holds the bloc’s largest network of ocean science institutions and the most extensive maritime boundaries, stretching from Réunion in the South Pacific to Saint Martin in the Caribbean to the Scattered Islands in the Indian Ocean.

This reporting is supported by a grant from the Walton Family Foundation, with The Associated Press retaining full editorial control over all content.

Beneath the baking summer sun where crowds of tourists queue to climb the iconic Notre Dame cathedral and glimpse its famous gargoyles, an unprecedented archaeological excavation is unfolding 13 feet underground. This dig is not just a side project to post-fire reconstruction: it is a journey back through millennia, pulling back the curtain on the layered origins of Paris, from its Roman beginnings to the medieval era and beyond.

Five years after a devastating 2019 fire collapsed Notre Dame’s spire in an event watched by the world, the historic cathedral completed its extensive reconstruction and reopened to the public in late 2024. As part of post-reopening improvements, city officials planned to transform the harsh, sunbaked public square in front of the cathedral into a greener, shaded space to accommodate visitors and combat rising temperatures linked to climate change. Under French archaeological protection rules, however, any ground disturbance for construction must be preceded by full excavation to protect undiscovered historical artifacts. What began as a pre-construction survey quickly grew into what local French media has dubbed the “dig of the century.”

“It’s a rare opportunity for us to work on something that’s tangibly going to make a difference to the history of Paris,” explained Lucie Altenburg, a conservator with Paris’ municipal archaeology unit, in an interview with the Associated Press. Already, the small excavation team has uncovered hundreds of significant objects, ranging from a well-preserved 4th-century Roman coin bearing the portrait of Emperor Constantine to fragments of medieval pottery marked with undeciphered symbols that have left experts baffled — a puzzle many on site compare to a real-life ancient Da Vinci Code.

For tourists visiting the newly reopened landmark, the active dig has added an unexpected layer of magic to their trip. “It makes Notre Dame feel alive again,” shared Emily Carter, a 34-year-old visitor from Manchester who was waiting in the tourist line with her two children. “You come to see the cathedral, then realize there’s another city under your feet. That’s almost more moving.” Just 20 inches below the surface, the first traces of earlier settlements emerge, and the team has continued to recover new artifacts all the way down to the 13-foot depth. On busy dig days, the team fills up to 15 crates of finds from ground that has remained undisturbed for hundreds of years.

This type of layered urban archaeology is not unique to Paris, but it offers one of the clearest glimpses into how ancient cities evolve. As the old adage goes: in historic global cities, the past is not kept in a distant museum — it lies directly beneath the modern streetscape. Every successive civilization builds its new structures atop the rubble of the one that came before it, pushing the ground level higher over centuries. For context, ground level in central Rome has risen roughly 30 feet since the fall of the Western Roman Empire in the 5th century, and the large-scale Athens metro construction ahead of the 2004 Olympics triggered the largest archaeological excavation in Greek modern history, unearthing tens of thousands of artifacts that are now displayed directly in the city’s metro stations. Paris is no exception to this rule.

All of Paris traces its origins to the small Ile de la Cite, the island in the Seine River where Notre Dame now stands. When construction first began on the cathedral in 1163, the entire forecourt area was tightly packed with medieval homes, divided only by a single narrow street, according to Camille Colonna, the lead archaeologist heading the excavation. Colonna’s team has already excavated down to the cellars of these long-gone medieval homes, placing them firmly in their historical context. Deeper still beneath these cellars lie grain pits dating to the Merovingian and Carolingian eras, between the 6th and 10th centuries. Further down, researchers have uncovered a dense residential quarter from Roman Lutetia, dating to the 4th and 5th centuries. In total, 20 centuries of human settlement are compressed into just 4 meters of earth — roughly the height of two and a half Napoleon Bonapartes stacked atop one another.

“Here you can see the layers — medieval Paris, Roman Paris, maybe even before that,” said Yasmine Benali, a 22-year-old archaeology student observing the dig from behind public barriers. “It makes the city feel less like a postcard and more like something still being discovered.”

Some of the most well-preserved finds have come from an unexpected source: the deep medieval latrine pits that doubled as community trash dumps centuries ago. The anaerobic, soft waste environment cushioned fragile ceramic objects, leaving many fully intact even after hundreds of years. The team has pulled whole jugs, cups, and drinking vessels out of these pits, alongside broken pottery fragments and animal bones. “It’s rare to find complete ceramics,” noted Valentine Breloux, an archaeologist with the Paris unit, adding that the intact pottery recovered at the site is nothing short of miraculous.

The most puzzling discovery so far is a series of faint red markings painted on the inner surface of multiple medieval pottery shards. No expert has yet been able to decode the meaning of the repeated symbols, which Breloux describes as the most “astonishing” find from the dig to date.

Coins recovered from the dig also play a critical scientific role beyond their historical value. After cleaning and X-ray analysis, one heavily corroded black disc was confirmed to be a 4th-century coin bearing the face of Emperor Constantine, who ruled Rome in the early 300s AD. Dated objects like these coins allow archaeologists to accurately assign timelines to each stratigraphic layer of the excavation, Altenburg explained.

For the research team, the Roman-era finds are the most valuable, as they fill major gaps in historical knowledge. Researchers have long known that the center of Roman Lutetia was originally located on the Seine’s Left Bank, and as the Roman Empire collapsed in Western Europe, the local population retreated to the defensible Ile de la Cite, reusing stone from older Roman structures to build new fortifications. The Notre Dame dig has already turned up physical proof of this practice: a large Roman doorstep, taken from a much grander public building, flipped upside down, and repurposed as paving stone for a medieval road.

All artifacts recovered from the excavation are transported to Paris’ central regional archaeology center, a large, secure storage facility Colonna describes as “a huge archaeological store” and a hidden treasure house of Parisian history.

For archaeological teams across Europe, large open urban digs like this only happen when major construction is scheduled, a dynamic Altenburg compares to industrial quarry workers stumbling on dinosaur fossils. “This only happens because the city of Paris decided it wanted to beautify the area,” she said.

The redevelopment of Notre Dame’s forecourt is scheduled for completion by 2028. The new public space will be designed as a shaded woodland clearing, planted with 160 new trees and fitted with a shallow cooling water feature to combat the extreme summer heat waves that have become more frequent due to climate change. Tourists who currently wait in direct sun to enter the cathedral will eventually queue in cool shade, and the existing underground parking lot will be redeveloped into a new public visitor center overlooking the Seine.

Until construction begins, however, the excavation team plans to continue digging deeper, pushing past the Roman layers to search for traces of the Gaulish settlement that gave Paris its original name. “The hope is that we are able to go back in time even further than we’ve ever been before,” Altenburg said.