urchins
margarita or turbo snails
blennies
all have been seen to eat it. but i digress
those are preventatives, the indication here is to hand clean it. make that all gone by tomorrow, then input the desired clean up crew to mow the grow back, if they choose to. Since they can opt out of cleaning for you, thats why the best measure is to remove invasions by hand, cheat or chemical and then use clean up crews as demoted removal crews.
the most common advise would be to remove the algae by hand any ole creative way, then employ some phosphate binding
We can clean the hound out of that with peroxide if you ever want to try, it sure has a big following online, before and after pics galore. google some and holler back if you want to tune up that beast~