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Scientists map uncharted waters of Britain's Caribbean territories
A six-week research mission has revealed underwater mountain ranges, a vast blue hole, and marine life never documented before in the deep waters surrounding the Cayman Islands, Anguilla, and Turks and Caicos.
Discovery of untouched ecosystems
Operating around the clock, the team deployed cameras and sensors capable of withstanding pressures at depths of up to 6,000 meters (19,700 feet). Their findings include coral reefs unaffected by climate change, glowing sea creatures, and geological formations absent from existing maps.
Professor James Bell, leading the expedition aboard the RSS James Cook, described the biodiversity as "astonishing." Among the discoveries was a previously unknown species of swimming sea cucumber, spotted just a day before the mission concluded.
New species and geological wonders
The team recorded nearly 14,000 individual specimens across 290 marine species, though further analysis is required to confirm their identities. Highlights include a pelican eel with a bioluminescent pink tail, a barreleye fish with upward-facing tubular eyes, and a dragonfish equipped with a glowing lure under its chin.
One of the most striking finds was Pickle Bank, an underwater mountain north of Little Cayman. Rising from 2,500 meters (8,200 feet) to just 20 meters (65 feet) below the surface, its slopes teem with golden coral towers, brain-like coral formations, and vibrant sea sponges.
Pristine reefs and a record-breaking blue hole
The expedition documented one of the Caribbean's healthiest reefs, shielded from stony coral disease by its depth and steep terrain. These mesophotic reefs, lying beyond the reach of warming surface waters, offer a glimpse of ecosystems untouched by climate-driven damage that has affected 80% of global corals since 2023.
Off Turks and Caicos, researchers identified a 3,200-meter (10,500-foot) mountain ridge stretching 70 kilometers (45 miles), missing from all existing nautical charts. They also located a massive blue hole-a vertical sinkhole formed by a collapsed cave-measuring 300 meters (980 feet) wide and plunging 550 meters (1,800 feet) deep. Cameras revealed sponges, urchins, and fish thriving within its walls, challenging the assumption that blue holes are lifeless.
Implications for conservation and local communities
The findings will inform biodiversity management plans and sustainable fishing practices for the three island territories, which host 146 species found nowhere else. Environmental experts from the Cayman Islands, Anguilla, and Turks and Caicos collaborated on the mission as part of the UK's Blue Belt Programme.
"Our islands were born from the sea, yet we've had little opportunity to explore what lies offshore,"
Kelly Forsythe, Cayman Islands Department of Environment
The data will also support the UK's commitment to protect 30% of global oceans by 2030 under UN agreements. Professor Bell emphasized the need for accurate mapping: "You can't just draw a box on a map and call it a marine protected area without knowing what's inside."
Challenges of deep-sea exploration
The team relied on outdated maps with significant inaccuracies, navigating uncharted terrain to avoid running aground. Bell noted the irony of knowing more about the surfaces of Mars and the Moon than Earth's own ocean floor. "We can map those in weeks with satellites," he said. "Our oceans require painstaking, piece-by-piece surveys using ship-based acoustic instruments."
