title: Reef-scale trends in FloridaAcroporaspp. abundance and the effects of population enhancement.
abstract: Since the listing ofAcropora palmataandA. cervicornisunder the US Endangered Species Act in 2006, increasing investments have been made in propagation of listed corals (primarilyA. cervicornis,A. palmatato a much lesser extent) in offshore coral nurseries and outplanting cultured fragments to reef habitats. This investment is superimposed over a spatiotemporal patchwork of ongoing disturbances (especially storms, thermal bleaching, and disease) as well as the potential for natural population recovery. In 2014 and 2015, we repeated broad scale (>50 ha), low precisionAcroporaspp. censuses (i.e., direct observation by snorkelers documented via handheld GPS) originally conducted in appropriate reef habitats during 2005-2007 to evaluate the trajectory of local populations and the effect of population enhancement. Over the decade-long study,A. palmatashowed a cumulative proportional decline of 0.4 -0.7x in colony density across all sites, despite very low levels of outplanting at some sites.A. cervicornisshowed similar proportional declines at sites without outplanting. In contrast, sites that receivedA. cervicornisoutplants showed a dramatic increase in density (over 13x). Indeed, change inA. cervicorniscolony density was significantly positively correlated with cumulative numbers of outplants across sites. This study documents a substantive reef-scale benefit ofAcroporaspp. population enhancement in the Florida Keys, when performed at adequate levels, against a backdrop of ongoing population decline.
authors.affiliation: Southeast Fisheries Science Center, NOAA-National Marine Fisheries Service , Miami , FL , United States.
authors.forename: Margaret W
authors.initials: MW
authors.lastname: Miller
authors.affiliation: Rosenstiel School of Marine and Atmospheric Sciences/Cooperative Institute of Marine and Atmospheric Studies, University of Miami , Miami , FL , United States.
authors.forename: Katryna
authors.initials: K
authors.lastname: Kerr
authors.affiliation: Southeast Fisheries Science Center, NOAA-National Marine Fisheries Service, Miami, FL, United States; Rosenstiel School of Marine and Atmospheric Sciences/Cooperative Institute of Marine and Atmospheric Studies, University of Miami, Miami, FL, United States.
authors.forename: Dana E
authors.initials: DE
authors.lastname: Williams
keywords: Bleaching; Coral nursery; Coral restoration; Florida Keys; Outplanting; Spatial analysis