Effects of climate change and light limitation on coral recruits

Climate change impacts and light attenuation from suspended sediments, due to runoff, natural resuspension or dredging, can both impede the replenishment of coral populations. Here we tested independent combined climate (current temperature dissolved CO 2 , future scenarios) a 1 mo long period at 5 different levels (0.1 4 mol photons m -2 d -1 ) on early Acropora millepora recruits. Additionally, evaluated whether effects were age dependent by comparing responses recruits that old (‘early attenuation’) vs. (‘late attenuation’). Recruit survival, size Symbiodiniaceae densities increased slightly under moderate conditions +0.44°C, 692 ppm pCO ), but decreased more severe scenario (+0.94°C, 985 ). Light significantly recruit only for exposed late attenuation, suggesting an increasing reliance photosynthesis as age. Under tested, survival was diminished (≤18 ± 4% [SE] in attenuation) limitation (≤32 6% compared with controls. However, there no interaction between scenarios indicating these additive. This study demonstrates potential recruitment success highlights need manage timing sediment-generating activities near reefs optimise availability several months post settlement.