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.
Witness predation while meditating.
Add all secret shells to your collection.
Breach the water on the back of a blue whale.
Discover the polar region.
Discover those that lurk in the abyss.
Perform a flip while riding a creature.
Complete the adventure.
Ride the Great White Shark.
Burst 15 fish schools in the jetstream.
Leap from the water.