Breed a blue whale to max level.
Breed a Turtle to Level 3.
Breed a Seahorse to Level 3.
Breed a pearl mussel to Level 3.
Breed a hermit crab to Level 3.
Breed a jelly fish to Level 3.
Breed a Prego to level 3.
Breed a Tropical fish to level 3.
The entire screen is coins!
Upgrade mermaid to Level 3.
Buy a mermaid.