Do the Atlantic and Pacific Oceans Mix?

Yes, the Atlantic and Pacific Oceans mix continuously through several pathways:

1. Drake Passage (between Cape Horn and Antarctic Peninsula) – primary deep-water connection; Antarctic Circumpolar Current flows unimpeded, exchanging heat, salt, nutrients, and plankton.
2. Strait of Magellan & Beagle Channel – shallow, coastal routes around southern South America.
3. Panama Canal – artificial 82-km lock canal (opened 1914); limited water exchange (freshwater Gatun Lake), but species transfer occurs (Lessepsian migration).
4. Arctic routes – Northwest Passage, Northern Sea Route; seasonal ice melt increasing connectivity.

The "two oceans don't mix" viral videos show a temporary estuarine front where glacial meltwater (light, sediment-laden) meets saline ocean water—distinct layers persist for kilometers but eventually mix via turbulence. The global ocean is one interconnected system; the named basins are human conveniences.