Lenz Elizabeth A, Donahue Megan J, Gates Ruth D, Putnam Hollie M, van der Steeg Eveline, Padilla-Gamiño Jacqueline L
University of Hawai'i Sea Grant College Program, University of Hawai'i at Mānoa, Honolulu, HI, United States of America.
Hawai'i Institute of Marine Biology, University of Hawai'i at Mānoa, Kāne'ohe, HI, United States of America.
PLoS One. 2025 Jan 7;20(1):e0290479. doi: 10.1371/journal.pone.0290479. eCollection 2025.
Identifying processes that promote coral reef recovery and resilience is crucial as ocean warming becomes more frequent and severe. Sexual reproduction is essential for the replenishment of coral populations and maintenance of genetic diversity; however, the ability for corals to reproduce may be impaired by marine heatwaves that cause coral bleaching. In 2014 and 2015, the Hawaiian Islands experienced coral bleaching with differential bleaching susceptibility in the species Montipora capitata, a dominant reef-building coral in the region. We tested the hypothesis that coral bleaching resistance enhances reproductive capacity and offspring performance by examining the reproductive biology of colonies that bleached and recovered (B) and colonies that did not bleach (NB) in 2015 in the subsequent spawning seasons. The proportion of colonies that spawned was higher in 2016 than in 2017. Regardless of parental bleaching history, we found eggs with higher abnormality and bundles with fewer eggs in 2016 than 2017. While reproductive output was similar between B and NB colonies in 2016, survivorship of offspring that year were significantly influenced by the parental bleaching history (egg donor × sperm donor: B × B, B × NB, NB × B, and NB × NB). Offspring produced by NB egg donors had the highest survivorship, while offspring from previously bleached colonies had the lowest survivorship, highlighting the negative effects of bleaching on parental investment and offspring performance. While sexual reproduction continues in M. capitata post-bleaching, gametes are differentially impacted by recovery time following a bleaching event and by parental bleaching resistance. Our results demonstrate the importance of identifying bleaching resistant individuals during and after heating events. This study further highlights the significance of maternal effects through potential egg provisioning for offspring survivorship and provides a baseline for human-assisted intervention (i.e., selective breeding) to mitigate the effects of climate change on coral reefs.
随着海洋变暖变得更加频繁和严重，识别促进珊瑚礁恢复和恢复力的过程至关重要。有性繁殖对于珊瑚种群的补充和遗传多样性的维持至关重要；然而，珊瑚的繁殖能力可能会受到导致珊瑚白化的海洋热浪的损害。2014年和2015年，夏威夷群岛经历了珊瑚白化，该地区主要的造礁珊瑚头状蔷薇珊瑚（Montipora capitata）的白化易感性存在差异。我们通过检查2015年白化并恢复的群体（B）和未白化的群体（NB）在随后产卵季节的生殖生物学，来检验珊瑚抗白化能力增强生殖能力和后代性能这一假设。2016年产卵的群体比例高于2017年。无论亲本的白化历史如何，我们发现2016年的卵异常率更高，卵束中的卵数量比2017年更少。虽然2016年B群体和NB群体的生殖产量相似，但当年后代的存活率受到亲本白化历史的显著影响（卵供体×精子供体：B×B、B×NB、NB×B和NB×NB）。由NB卵供体产生的后代存活率最高，而来自先前白化群体的后代存活率最低，这突出了白化对亲本投资和后代性能的负面影响。虽然头状蔷薇珊瑚在白化后仍继续进行有性繁殖，但配子受到白化事件后的恢复时间和亲本抗白化能力的不同影响。我们的结果证明了在升温事件期间和之后识别抗白化个体的重要性。这项研究进一步强调了母体效应通过潜在的卵子供应对后代存活的重要性，并为人类辅助干预（即选择性育种）减轻气候变化对珊瑚礁的影响提供了一个基线。
