Abstract
For decades, coral reef ecosystems have been in decline due to environmental stressors such as rising sea temperatures, increased disease prevalence, and other local anthropogenic sources. Considering this decline, coral restoration efforts in the Caribbean have been implemented to promote reef recovery with a focus on the coral genus Acropora. Current methods target the threatened species Acropora cervicornis and A. palmata, but little is known about the restoration potential of their hybrid taxon, A. prolifera. Using interspecific hybrids with higher fitness than one or both parental species has gained traction as a novel restoration technique. For this study, three in situ coral tree nurseries were established around Great Stirrup Cay, The Bahamas, to compare the growth and survival among acroporid taxa. Three 150 mm fragments from six putative genotypes of each acroporid taxa were collected from reefs around New Providence, The Bahamas, and transported to Great Stirrup Cay in June 2018. One fragment from each genotype was transported to each nursery site, cut into three sections (apical, middle, and basal), and suspended from PVC coral trees. Fragment survival was collected monthly for 13 months, and Total Linear Extension (TLE) values were calculated for each fragment monthly for 12 months. Nursery site significantly affected fragment survival, while taxon and fragment section did not. Total fragment mortality was 29.3% in the first month but ranged from 0 to 5% for the rest of the study period until July 2019 (32.7% of remaining fragments died primarily at N1). Overall, A. prolifera growth was significantly greater than the parental species. Taxon, nursery site, and fragment section were identified as important factors affecting TLE. Apical A. prolifera fragment sections at site N3 had the greatest average linear growth at 12 months and had the greatest average growth rate per month. This study highlights the rapid growth rate of hybrid corals and suggests that fragment sections have equivalent survival and growth. Consequently, these results suggest that restoration managers may capitalize on fast growing hybrids for outplanting to degraded reefs and to increase the scale of nursery projects.
Highlights
In the face of climate change and other environmental threats, conservation and restoration of the world’s natural resources are at the forefront of scientific research (Harris et al, 2006; Heller and Zavaleta, 2009; Jackson and Hobbs, 2009)
Of the initial 157 fragments, 66 (42%) survived to the end of the study period (13 months). Of those fragments surviving at 13 months, 28.8% were A. cervicornis fragments, 31.5% were A. palmata fragments, and 39.7% were A. prolifera fragments
This study identified three main findings that will be beneficial to restoration management: (1) the hybrid taxon, A. prolifera, demonstrated greater growth in a shallow water nursery setting than the parental species, (2) using non-apical fragments did not compromise survival or growth, and (3) nursery site selection plays an important role in coral fragment survival
Summary
In the face of climate change and other environmental threats, conservation and restoration of the world’s natural resources are at the forefront of scientific research (Harris et al, 2006; Heller and Zavaleta, 2009; Jackson and Hobbs, 2009) Global issues such as deforestation, rising global temperatures, pollution, and the overuse of natural resources are serious threats to marine ecosystems and terrestrial environments (Vitousek, 1994; Derraik, 2002; Shahidul Islam and Tanaka, 2004; Harley et al, 2006; Malhi et al, 2008; Cinner et al, 2015; Hughes et al, 2017b). Disturbance to a reef is natural but continued impacts of chronic stressors has changed coral reef community composition from one benthic group to another (Hughes et al, 1985; Hughes, 1994; Lirman, 2001; Bellwood et al, 2004; Knowlton and Jackson, 2008; Jackson et al, 2014; Jones et al, 2020)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
