McRae Crystal J, Huang Wen-Bin, Fan Tung-Yung, Côté Isabelle M
Department of Natural Resources and Environmental Studies, National Dong Hwa University, Hualien, Taiwan.
Department of Biological Sciences, Simon Fraser University, British Columbia, Canada.
Coral Reefs. 2021;40(5):1491-1503. doi: 10.1007/s00338-021-02123-9. Epub 2021 Jul 21.
Ocean warming induced by climate change is the greatest threat to the persistence of coral reefs globally. Given the current rate of ocean warming, there may not be sufficient time for natural acclimation or adaptation by corals. This urgency has led to the exploration of active management techniques aimed at enhancing thermal tolerance in corals. Here, we test the capacity for transgenerational acclimation in the reef-building coral as a means of increasing offspring performance in warmer waters. We exposed coral colonies from a reef influenced by intermittent upwelling and constant warm-water effluent from a nuclear power plant to temperatures that matched (26 °C) or exceeded (29.5 °C) season-specific mean temperatures for three reproductive cycles; offspring were allowed to settle and grow at both temperatures. Heated colonies reproduced significantly earlier in the lunar cycle and produced fewer and smaller planulae. Recruitment was lower at the heated recruitment temperature regardless of parent treatment. Recruit survival did not differ based on parent or recruitment temperature. Recruits from heated parents were smaller and had lower maximum quantum yield (Fv/Fm), a measurement of symbiont photochemical performance. We found no direct evidence that thermal conditioning of adult corals improves offspring performance in warmer water; however, chronic exposure of parent colonies to warmer temperatures at the source reef site may have limited transgenerational acclimation capacity. The extent to which coral response to this active management approach might vary across species and sites remains unclear and merits further investigation.
The online version contains supplementary material available at 10.1007/s00338-021-02123-9.
气候变化导致的海洋变暖是全球珊瑚礁持续存在面临的最大威胁。鉴于当前海洋变暖的速度，珊瑚可能没有足够的时间进行自然适应或驯化。这种紧迫性促使人们探索旨在提高珊瑚耐热性的主动管理技术。在此，我们测试造礁珊瑚的跨代适应能力，以此作为提高后代在温暖水域中生存能力的一种手段。我们将来自受间歇性上升流和核电站恒定温水排放影响的珊瑚礁的珊瑚群体，在三个繁殖周期内暴露于与特定季节平均温度匹配（26°C）或超过（29.5°C）的温度下；后代在这两种温度下都能定居并生长。受热的珊瑚群体在月周期中繁殖显著提前，且产生的浮浪幼虫数量更少、体型更小。无论亲代处理如何，在受热的招募温度下招募率都较低。幼体存活率不受亲代或招募温度的影响。来自受热亲代的幼体体型较小，最大量子产量（Fv/Fm）较低，这是共生体光化学性能的一种衡量指标。我们没有直接证据表明成年珊瑚的热预处理能提高后代在温暖水域中的生存能力；然而，亲代群体在源礁位点长期暴露于较高温度可能限制了跨代适应能力。珊瑚对这种主动管理方法的反应在不同物种和位点上的差异程度尚不清楚，值得进一步研究。
在线版本包含可在10.1007/s00338-021-02123-9获取的补充材料。
