Successfully complete one of the following tasks to get a trophy:

Too easy! (Bronze): Finish first level in Adventure mode.
Sea Cucumber (Bronze): Save at least 1400 fish in Adventure mode
or Freeplay mode.
Sea Urchin (Bronze): Save at least 2800 fish in Adventure mode or
Freeplay mode.
Sea Horse (Bronze): Save at least 4200 fish in Adventure mode or
Freeplay mode.
Sunfish (Bronze): Save at least 5600 fish in Adventure mode or
Freeplay mode.
Angling (Bronze): Finish 20 levels in a row in Random Survival mode.
Dip net fishing (Bronze): Finish 25 levels in a row in Random
Survival mode.
Starfish (Silver): Save at least 7000 fish in Adventure mode or
Freeplay mode.
Net fishing (Silver): Finish 32 levels in a row in any Survival mode.
Like a fish in water (Gold): Finish Adventure mode.