AUTHOR=Maneval Paul , Jacoby Charles A. , Harris Holden E. , Frazer Thomas K. 

TITLE=Genotype, Nursery Design, and Depth Influence the Growth of Acropora cervicornis Fragments

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 8 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2021.670474

DOI=10.3389/fmars.2021.670474

ISSN=2296-7745

ABSTRACT=Growing fragments of corals in nurseries and outplanting them to supplement declining natural populations has gained significant traction in the Caribbean and elsewhere. In the Caribbean for example, this approach provides colonies of Acropora cervicornis with minimal impacts to existing wild colonies. Given the impetus to scale up production to augment limited natural recovery, managers and researchers should consider how the design and location of the nurseries affect the growth of different genotypes of corals and the effort required for maintenance. To elucidate such influences, we grew fragments of different genotypes (5 varieties) on differing structures (trees and frames) at two depths (6–8 m and 16–18 m). Total linear extensions, accumulation of biofouling, and cleaning time were measured over 198 d to assess the growth of fragments and the effort required to maintain nurseries. Total linear extensions for all fragments increased linearly throughout the incubation period. Mean daily incremental growth rates varied among the genotypes, with one genotype growing significantly faster than all others, two genotypes growing at intermediate rates, and two genotypes growing more slowly. Mean daily incremental growth rates were higher for all genotypes suspended from vertical frames at both sites, and mean daily incremental growth rates were higher for all fragments held on both types of nurseries in deeper water. If linear growth continued, estimated mean annual growth for a fragment of the fastest growing genotype held on a frame in deeper water would be 88 cm y-1, which was over two times higher than the estimated annual growth rate for a fragment of the slowest growing genotype held on a tree in shallow water. The time required for maintenance did not vary consistently, but deep nurseries had significantly less biofouling and appeared to be buffered against daily fluctuations in temperature. Overall, the results demonstrated that improved production and reduced maintenance can result from considering the genotype of fragments to be cultured and the design and location of nurseries.