10 Fascinating Sea Facts: From Depths to Climate Regulation

1. Earth Is Mostly Ocean

~71% of Earth's surface (361 million km²) is covered by seawater.

2. Deepest Point: Mariana Trench

Challenger Deep reaches ~11,000 m (6.8 mi) in the western Pacific.

3. Highest Ocean Point: Mauna Kea (Not Everest)

Measured from base on the ocean floor, Mauna Kea (Hawaii) is ~10,210 m tall—surpassing Everest's 8,848 m above sea level.

4. Vast Biodiversity

~240,000 known marine species; estimates suggest 1–2 million total.

5. Climate Regulator

Oceans absorb ~90% of excess heat and ~30% of CO₂, producing ~50% of oxygen via phytoplankton.

6. Resource Reservoir

Food (fish provide 17% of global animal protein), energy (wave, tidal, offshore wind), minerals (polymetallic nodules, oil, gas).

7. Global Trade Highway

Over 80% of international trade by volume moves by sea.

8. Recreation and Wellbeing

Coastal tourism, swimming, diving, sailing, surfing—major economic and health drivers.

9. Largely Unexplored

Less than 20% of the seafloor mapped at high resolution; new species discovered regularly.

10. Under Human Threat

Plastic pollution (8–12 million tonnes/year), overfishing (34% stocks overfished), acidification, warming, and habitat destruction.

Protecting the ocean is essential for climate stability, food security, and planetary health.