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