Genetic diversity of farmed and wild populations of the reef‐building coral, Acropora tenuis

Abstract

Transplantation of nursery-farmed corals is a primary management tool for restoration of degraded coral reefs. However, there have been concerns about the potential loss of genetic diversity in nurseries due to asexual propagation methods used to prepare transplants. Two coral nurseries at Maeganeku and Onna, Okinawa Island, Japan, furnish source material for regional restoration activities. Using 13 microsatellite markers, this study compared the genetic diversity of 132 Acropora tenuis colonies from these nurseries with that of 298 wild colonies from 15 sites across the Nansei Islands. Even though no clonal colonies were detected at wild sites, we estimated clonal richness of farmed corals to be 0.523 (Maeganeku) and 0.579 (Onna). Genotypic diversity is high in the nursery populations, 0.894 (Maeganeku) and 0.937 (Onna), but lower than in the natural populations (1.000). However, expected heterozygosity did not differ significantly between locations, including the coral nurseries (one-way analysis of variance, p > 0.05). Inbreeding coefficients of nursery populations (Onna, −0.019 to Maeganeku, 0.097) fell within the range of estimates from wild populations (Sesoko, −0.058 to Maeda, 0.278). Furthermore, based on Structure analysis, farmed A. tenuis comprises the same genetic population that occupies the surrounding natural area. Thus, given no additional statistically significant increase of clonal colonies within nurseries, using farmed coral assemblages for reef restoration may be preferable to transplanting and damaging wild assemblages. Coral gametes of farmed colonies may also be used to produce coral larvae for transplantation of sexually propagated corals.

Genome‐wide SNP genotyping reveals hidden population structure of an acroporid species at a subtropical coral island: Implications for coral restoration

“…Our results illustrate a difference in population structure between A. digitifera and A. tenuis in this study area, consistent with previous studies using whole‐genome SNPs (Shinzato et al, 2015) and microsatellite markers (Nakajima et al, 2010; Zayasu et al, 2016; Zayasu, Satoh & Shinzato, 2018). Whole‐genome approaches incur greater sequencing costs and effort, and SNPs obtained by MIG‐seq yield more statistical power than do microsatellites.…”

Seascape genetics and connectivity modelling for an endangered Mediterranean coral in the northern Ionian and Adriatic seas

“…This result is not unusual in corals (e.g. Ayre and Hughes 2000;Severance and Karl 2006;Goffredo et al 2009;Polato et al 2010;Casado-Amezu ´a et al 2012;Zayasu et al 2018;Evans et al 2019), and can be an indication of biological and demographical features of the analysed populations (e.g. population effective size, inbreeding, population mixing, non-random mating or asexual reproduction).…”

Assessing and genotyping threatened staghorn coral Acropora cervicornis nurseries during restoration in southeast Dominican Republic

“…Our genotype identification established a baseline that will allow for the future spatially distributed selection of colonies in outplanted sites (Baums, 2008;Schopmeyer et al, 2012). This is also useful for future studies on genotype resistance against different stressors, such as high sedimentation, temperature increase, and predation by fireworms (Lundgren et al, 2013;Zayasu, Satoh & Shinzato, 2018).…”