SECORE International, Miami, FL, United States of America.
Unidad Académica de Sistemas Arrecifales, Universidad Nacional Autónoma de México, Puerto Morelos, Quintana Roo, México.
PLoS One. 2024 Sep 18;19(9):e0309719. doi: 10.1371/journal.pone.0309719. eCollection 2024.
Assisted sexual coral propagation, resulting in greater genet diversity via genetic recombination, has been hypothesized to lead to more adaptable and, hence, resilient restored populations compared to more common clonal techniques. Coral restoration efforts have resulted in substantial populations of 'Assisted sexual Recruits' (i.e., juvenile corals derived from assisted sexual reproduction; AR) of multiple species outplanted to reefs or held in in situ nurseries across many locations in the Caribbean. These AR populations provided context to evaluate their relative resilience compared to co-occurring coral populations during the 2023 marine heat wave of unprecedented duration and intensity that affected the entire Caribbean. Populations of six species of AR, most ranging in age from 1-4 years, were surveyed across five regions during the mass bleaching season in 2023 (Aug-Dec), alongside co-occurring groups of corals to compare prevalence of bleaching and related mortality. Comparison groups included conspecific adult colonies as available, but also the extant co-occurring coral assemblages in which conspecifics were rare or lacking, as well as small, propagated coral fragments. Assisted sexual recruits had significantly lower prevalence of bleaching impacts (overall pooled ~ 10%) than conspecific coral populations typically comprised of larger colonies (~ 60-100% depending on species). In addition, small corals derived from fragmentation (rather than sexual propagation) in two regions showed bleaching susceptibility intermediate between AR and wild adults. Overall, AR exhibited high bleaching resistance under heat stress exposure up to and exceeding Degree Heating Weeks of 20°C-weeks. As coral reefs throughout the globe are subject to increasingly frequent and intense marine heatwaves, restoration activities that include sexual reproduction and seeding can make an important contribution to sustain coral populations.
辅助有性珊瑚繁殖，通过遗传重组产生更大的遗传多样性，这被假设为导致更适应环境的、因此更具恢复力的修复种群，与更常见的克隆技术相比。珊瑚修复工作已经在加勒比地区的许多地方的珊瑚礁上种植了大量的“辅助有性繁殖的珊瑚苗”（即通过辅助有性繁殖产生的幼年珊瑚；AR），或者在原地苗圃中进行养殖。这些 AR 种群为评估它们在与同时存在的珊瑚种群相比的相对恢复力提供了背景，在这场影响整个加勒比地区的、前所未有的持续时间和强度的 2023 年海洋热浪中，这些种群与同时存在的珊瑚种群一起受到了影响。在 2023 年大规模白化季节（8 月至 12 月），对五个地区的六种 AR 物种的种群进行了调查，同时还对同时存在的珊瑚群进行了调查，以比较白化病的流行程度和相关死亡率。比较组包括有可用的同种成年群体，但也包括同时存在的珊瑚组合，其中同种珊瑚很少或没有，以及小的、繁殖的珊瑚碎片。辅助有性繁殖的珊瑚苗的白化影响患病率明显较低（总体 pooled~10%），而通常由较大珊瑚组成的同种珊瑚种群的患病率较高（取决于物种，约为 60-100%）。此外，在两个地区，来自碎片（而非有性繁殖）的小型珊瑚显示出的白化病易感性介于 AR 和野生成年珊瑚之间。总体而言，在暴露于热应激下，AR 在高达并超过 20°C 周数的 20 度加热周数的情况下，表现出高白化病抗性。随着全球珊瑚礁越来越频繁和强烈地受到海洋热浪的影响，包括有性繁殖和播种的修复活动可以为维持珊瑚种群做出重要贡献。
