You'll need to unlock Volcano for this achievement, meaning you need 130 Stars off the first 4 levels.
-Certain fish appear only at night or day. Change your internal clock or wait til the right time to spot these fish. You don't have to log off LIVE just change your timezone forward +12.
-The Abyss has no day/night fish obviously.
(I played at night so the Day fish are Clown Fish(Reef), Sea Snake(Grave) and Sea Lion(Deep))
-Check you Photo Log to see which fish are 0-1 Stars and aim for them. Throw your Gizmo, get them facing you, large and in the centre. If in doubt take lots of photos, your bound to get 1 right by accident.
-You can select Resurface from the pause menu to end the dive early and your photos count.
-You'll need 33 Stars on each level. (32.5 to be exact). You'll need to snap every fish and have 9 or 10 (from 12) at 3 Stars to be close.
-I found Deep Sea to be the hardest, mostly 2Stars on this.