The success of early life history transitions of the coral Acropora tenuis were used as endpoints to evaluate thermal stress and the effects of wastewater discharged to a tropical marine environment. The studies assessed the effects of: (i) temperature; (ii) three signature metals of the wastewater, aluminium (Al), vanadium (V) and gallium (Ga); and (iii) the wastewater (at 27°C and 32°C) on fertilisation and larval metamorphosis. The median inhibition temperatures for fertilisation and metamorphosis were 32.8°C and 33.0°C, respectively. Fertilisation IC 50s for Al, V and Ga were 2997, 2884 and 3430μgL -1, respectively. Metamorphosis IC 50s for Al, V and Ga were 1945, 675 and 3566μgL -1, respectively. The wastewater only affected fertilisation and metamorphosis at moderate concentrations (IC 50s=63% and 67%, v/v, respectively, at 27°C), posing a low risk to this species in the field. The effects of wastewater and temperature on fertilisation and metamorphosis were additive.