Both are marginal seas of the Atlantic, but differ in geography, climate, and ecology:
| Feature | Mediterranean Sea | Caribbean Sea |
|---|---|---|
| Area | 2.5M km² | 2.7M km² |
| Location | Europe, Africa, Asia | N. America, S. America, Central America |
| Climate | Mediterranean: hot dry summer, mild wet winter | Tropical: warm/humid year-round |
| Avg Water Temp | ~20°C (68°F) | ~25°C (77°F) |
| Salinity | High (38+ psu) – net evaporation | Lower (~35 psu) – high rainfall/runoff |
| Marine Life | Endemic-rich, temperate/subtropical | Coral reefs, high tropical diversity |
| Connection to Atlantic | Strait of Gibraltar (narrow, shallow) | Wide passages (Yucatán, Windward, Mona) |
| Depth | Avg 1,500 m; max 5,267 m (Calypso Deep) | Avg 2,200 m; max 7,686 m (Cayman Trench) |
| Iconic Coasts | French Riviera, Amalfi, Greek islands, Morocco | Cancún, Jamaica, Bahamas, Belize, Caymans |
Both are biodiversity hotspots under pressure from overfishing, pollution, climate change.