White, flower shaped growth on rocks

[badIuck]

Hello,
especially in the shadow I am getting this white, flower/star shaped growth on my rocks. About 5mm in diameter each. Anyone know if it's considered a pest?
Thanks!

 

[EeyoreIsMySpiritAnimal]

Can you post a pic under whites?

 

[badIuck]

There you go

 

[EeyoreIsMySpiritAnimal]

@ISpeakForTheSeas , tunicates?

 

[ScubaFish802]

@ISpeakForTheSeas , tunicates?

+2

 

[ISpeakForTheSeas]

@ISpeakForTheSeas , tunicates?

Yep, colonial tunicates:

As mentioned, colonial tunicates- some species grow really fast and may take up a lot of real estate if left unchecked, but they’re harmless (I’ve never heard of one doing damage) and should be relatively easy to remove on occasion if they get out of hand.