Here is the full list of all 12 ABZU achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Add all secret shells to your collection.
Find all the meditation statues.
Release fish from all the hidden pools.
Witness predation while meditating.
Complete the adventure.
Discover the polar region.
Breach the water on the back of a blue whale.
Ride the Great White Shark.
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.