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