Acute turbidity exposures with Port of Miami sediments impact Orbicella faveolata tissue regeneration.

ABSTRACT

We evaluated acute turbidity effects on a threatened coral species (Orbicella faveolata) under three short-term challenge scenarios using a Port of Miami sediment homogenate to simulate turbid conditions during dredging. For these experiments we designed a simple coral challenge test system that kept turbidity stable, without adverse effects to the coral. A 96-h coral challenge experiment demonstrated that low turbidity levels (≥4 NTU) have negative effects on O. faveolata tissue regeneration. A 48-h turbidity exposure (maximum 30 NTU) had no effect on O. faveolata tissue regeneration, showing that short term turbidity exposures may not be detrimental to coral health. In a 13-day test, treated coral fragments (maximum 30 NTU) exhibited significant delays in tissue regeneration, but recovery was observed after approximately one week. The results presented here can be used to inform management decisions for proposed dredging activities proximal to coral reef habitats.