Different resiliencies in coral communities over ecological and geological time scales in American Samoa

In 1917, Alfred Mayor surveyed a 270 m transect on reef flat American Samoa. Eleven surveys were conducted the from 1917 to 2019. The coral community crest was resilient over century, occasionally being seriously damaged but always recovering rapidly. contrast, originally most dense has been steadily deteriorating throughout century. Resilience of communities in regions high wave energy crests associated with important binding function crustose coralline alga (CCA) Porolithon onkodes . Successful recruits found CCA 94% time, yet living cover correlated negatively as they became alternative winners competition. drilled core surface basalt base 48 below. Communities Aua dominated by scleractinians through Holocene, while cores another 2 km away showed occupied alcyonaceans genus Sinularia , which built massive spiculite 37 Despite periods sea levels rising 9 15 times rate accretion, reefs never drowned. consistency and Utulei Reef during Holocene because shape bay allowed more water motion reef. After 10700 yr building octocorals, coastal construction terminated this spiculite-reef development.