Here is the full list of all 12 ABZU achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Discover the polar region.
Breach the water on the back of a blue whale.
Ride the Great White Shark.
Perform a flip while riding a creature.
Complete the adventure.
Witness predation while meditating.
Leap from the water.
Burst 15 fish schools in the jetstream.
Discover those that lurk in the abyss.
Release fish from all the hidden pools.
Find all the meditation statues.
Add all secret shells to your collection.