ocean

The deepest known point on Earth's surface sits 10,935 meters below sea level in the western Pacific — deeper than Everest is tall. At Challenger Deep in the Mariana Trench, the water pressure reaches 1,086 bar (15,750 psi), equivalent to 50 jumbo jets resting on a single square meter. Three crewed descents have reached this point, and each one found life there. The hadal zone, that alien strip of ocean below 6,000 meters, covers less than 1% of the seafloor but harbors organisms that have evolved in permanent darkness, crushing pressure, and near-freezing temperatures.

How coral animals build reefs, their algae symbiosis, why bleaching happens, and what conservation can still save. Learn the science, key examples, and...

Australia's Great Barrier Reef is the world's largest coral structure at 348,000 km². Indonesia has the most coral biodiversity. But 50% of the world's coral reefs have died since 1950 — bleaching events driven by ocean warming are accelerating. Here's the full coral reef ranking and the scale of the crisis.

The United States generates more plastic waste per capita than any large nation — 130 kg per person per year. But the Philippines, Indonesia, and India contribute the most plastic to the ocean. How you rank countries on plastic pollution depends entirely on whether you measure production, per-capita waste, or ocean contribution.

The ocean covers 71% of Earth's surface, and a coastal state controls the resources in the first 200 nautical miles off its shores. This ranking shows which nations hold the most maritime territory, why published figures disagree, and what an exclusive economic zone does and does not allow.

The United Kingdom protects 8.1 million km² of ocean — the most of any country. Australia's Great Barrier Reef Marine Park is the world's largest single MPA. The global target is 30% of oceans protected by 2030 (30x30). Currently only 8% is protected. Here's the full marine protection ranking.