Dehnert Inga, Saponari Luca, Galli Paolo, Montano Simone
Department of Earth and Environmental Sciences (DISAT), University of Milan-Bicocca, Milan, Italy.
MaRHE Center (Marine Research and High Education Center), Magoodhoo Island, Faafu Atoll, Republic of Maldives.
PeerJ. 2022 Feb 24;10:e12874. doi: 10.7717/peerj.12874. eCollection 2022.
The need for comprehensive and effective coral restoration projects, as part of a broader conservation management strategy, is accelerating in the face of coral reef ecosystem decline. This study aims to expand the currently limited knowledge base for restoration techniques in the Maldives by testing the performance of mid-water rope nurseries in a lagoon and a reef habitat. We examined whether different coral farming habitats impacted fragment survival, health and growth of two coral genera and how the occurrence of mutualistic fauna, predation and disease influenced coral rearing success. Two nurseries were stocked with a total of 448 and 96 spp. fragments, divided into different groups (four groups: lagoon nursery at 5 m; reef nursery at 5, 10 and 15 m; two groups: lagoon nursery at 5 m and reef nursery at 5 m). Eight fragment replicates from the same donor colony ( genets: = 14, genets = 6) were used in each group and monitored for one year. Our results show that fragment survival was high in both farming habitats (>90%), with surviving significantly better in the lagoon and spp. surviving and growing significantly faster in the reef nursery. growth rates were similar between reef and lagoon habitat. Different rearing depths in the reef nursery had no impact on the survival of but coral growth decreased considerably with depth, reducing fragments' ecological volume augmentation and growth rates by almost half from 5 to 15 m depth. Further, higher fish predation rates on fragments were recorded on the reef, which did not impact overall nursery performance. Mutualistic fauna, which correlated positively with fragment survival, was more frequently observed in the lagoon nursery. The occurrence of disease was noted in both habitats, even though implications for fragment health were more severe in the lagoon. Overall, our study demonstrates that lagoon and reef nurseries are suitable for rearing large numbers of coral fragments for transplantation. Nevertheless, we recommend considering the specific environmental conditions of the farming habitat, in particular water quality and year-round accessibility, in each case and to adjust the coral farming strategy accordingly. We hope that this novel research encourages the increased application of mid-water rope nurseries for 'coral gardening' to advance coral reef recovery and climate resilience in the Maldives.
面对珊瑚礁生态系统的衰退，作为更广泛的保护管理战略的一部分，全面有效的珊瑚恢复项目的需求正在加速。本研究旨在通过测试环礁湖和珊瑚礁栖息地中水层绳索苗圃的性能，扩大马尔代夫目前有限的恢复技术知识库。我们研究了不同的珊瑚养殖栖息地是否会影响两个珊瑚属碎片的存活、健康和生长，以及互利动物群的出现、捕食和疾病如何影响珊瑚养殖的成功率。两个苗圃共投放了448个和96个物种的碎片，分为不同组（四组：5米深处的环礁湖苗圃；5米、10米和15米深处的珊瑚礁苗圃；两组：5米深处的环礁湖苗圃和5米深处的珊瑚礁苗圃）。每组使用来自同一供体群体的八个碎片复制品（14个群体的碎片：鹿角珊瑚属；6个群体的碎片：滨珊瑚属），并监测一年。我们的结果表明，在两种养殖栖息地中碎片存活率都很高（>90%），鹿角珊瑚属在环礁湖中存活得明显更好，滨珊瑚属在珊瑚礁苗圃中存活和生长得明显更快。鹿角珊瑚属在珊瑚礁和环礁湖栖息地的生长速率相似。珊瑚礁苗圃中不同的养殖深度对鹿角珊瑚属的存活没有影响，但珊瑚生长随深度显著下降，从5米到15米深度，碎片的生态体积增加和生长速率几乎减半。此外，在珊瑚礁上记录到碎片的鱼类捕食率更高，但这并未影响苗圃的整体性能。互利动物群与碎片存活呈正相关，在环礁湖苗圃中更常被观察到。在两种栖息地都注意到了疾病的发生，尽管对碎片健康的影响在环礁湖中更严重。总体而言，我们的研究表明，环礁湖和珊瑚礁苗圃适合培育大量用于移植的珊瑚碎片。然而，我们建议在每种情况下都要考虑养殖栖息地的特定环境条件，特别是水质和全年可达性，并相应调整珊瑚养殖策略。我们希望这项新研究能鼓励更多地应用水层绳索苗圃进行“珊瑚园艺”，以促进马尔代夫珊瑚礁的恢复和气候适应能力。
