Recovery from finfish predation on newly outplanted boulder coral colonies on three reefs in the Florida Keys

Abstract

Corals throughout the Caribbean have experienced major declines since the 1970s. In response, many agencies have focused their conservation and restoration efforts on outplanting nursery-grown coral fragments onto degraded reefs. Predation on newly outplanted corals can be an important but often unmonitored factor contributing to the declining health and survival of these fragments. In this study, we outplanted 360 boulder coral fragments (Montastraea cavernosa, Orbicella faveolata, Pseudodiploria clivosa), sourced from both ex situ and in situ nurseries, at three locations in the Florida Keys. Each location included one inshore and one offshore site. Ten fragments of each species and source were outplanted at each site (60 corals per site). Transplants were monitored for finfish predation, live tissue area, and survival at 1, 2, 6, and 12 wks post-outplanting. We found the highest finfish predation for all species during the 1 wk monitoring period. Predation during this first week varied by location and reef type, with two locations showing higher predation on offshore sites and one location experiencing increased predation on the inshore site. We also found that coral fragments produced in the ex situ nursery experienced higher initial predation compared to fragments produced in the in situ nursery. However, overall coral survival at 12 wks post-outplanting was 96%, suggesting there was no effect of initial predation on survival. Our results indicate that coral restoration efforts may be affected by intense, initial predation on newly-outplanted boulder coral colonies, but this initial predation may not lead to an increase in mortality.