Trophies:

Bronze trophies
Too easy! – Finish first level in Adventure mode.
Sea Cucumber – Save at least 1400 fish in Adventure mode or Freeplay mode.
Sea Urchin – Save at least 2800 fish in Adventure mode or Freeplay mode.
Sea Horse – Save at least 4200 fish in Adventure mode or Freeplay mode.
Sunfish – Save at least 5600 fish in Adventure mode or Freeplay mode.
Angling – Finish 20 levels in a row in Random Survival mode.
Dip net fishing – Finish 25 levels in a row in Random Survival mode.

Silver trophies
Starfish – Save at least 7000 fish in Adventure mode or Freeplay mode.
Net fishing – Finish 32 levels in a row in any Survival mode.

Gold trophies
Like a fish in water – Finish Adventure mode.