How to get Coins
Hungry Shark Evolution Guide
Coins can be earned by eating the golden fish that you find around the map. If you eat enough fish in quick succession (whether they are golden or regular), you can also earn a Gold Rush. This activates a score multiplier and nabs you heaps of Coins to add to your collection - which can be crucial for purchasing new sharks.
You are also able to get Coins in the daily chest. Log in for repeated days and you will get more and more reward for your efforts.
Complete missions for additional Coins and stay alive for as long as possible to earn some as a survival bonus.