Novel mesophotic kelp forests in the Galapagos archipelago
Novel mesophotic kelp forests in the Galapagos archipelago
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DOI：
10.1007/s00227-022-04142-8
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发表时间：
2022-12-01
期刊：
影响因子：
2.4
通讯作者：
Altamirano, Maria
中科院分区：
文献类型：
--
作者：
Buglass, Salome;Kawai, Hiroshi;Altamirano, Maria
海带是全球研究最多的大型藻类群体之一，因为它们是形成世界上最具生产力和多样性的海洋栖息地的大型基础物种。然而，人们对热带海带的多样性和生态学知之甚少，它们往往栖息在更难以调查的中光区。加拉帕哥斯海海带是全球第一个被记录的热带海带物种，也是加拉帕戈斯特有的濒危物种。在这里，我们揭示了以前未知的离岸中光海带种群的存在，在加拉帕戈斯，由一个潜在的新品种的区域，并提出了遗传学和形态学分析，以支持我们的主张。我们发现，这些新的种群形成了广泛的海带森林栖息地，在48-67米深处的海带密度为2.6 +/- 1.5米（-2），平均水温比表面（18.1-19.9摄氏度）低3-5摄氏度。尽管光照和大量营养素水平较低（2019年8月测量），但对叶片上的幼藻和孢子囊群的观察表明，这些海带种群正在成功繁殖和招募。我们的研究结果提供了关于基础物种和复杂的海洋群落的信息，以前未知的管理人员的加拉帕戈斯海洋保护区。他们还支持这样一种观点，即该地区对棕色大型藻类的多样性具有独特的重要性。我们的研究强调了主要基础物种在较冷的中光区分布的关键知识差距，以及它们从表面的不可见性如何阻止它们纳入当前的保护战略。
Kelps are among the most studied groups of macroalgae globally, as they are large foundation species that form some of the world's most productive and diverse marine habitats. Yet little is known about diversity and ecology of tropical kelps, which tend to inhabit the more difficult to survey mesophotic zone. Eisenia galapagensis is the first tropical kelp species to be recorded globally, and is an endemic and endangered species to the Galapagos. Here, we reveal the presence of previously unknown off-shore mesophotic kelp populations in the Galapagos, made up by a potentially new Eisenia species for the region, and present phylogenetics and morphological analysis to support our claim. We find that these novel populations form extensive kelp forest habitats with a kelp density of 2.6 +/- 1.5 m(-2) at depths of 48-67 m, where mean water temperatures are 3-5 celcius cooler than at the surface (18.1-19.9 celcius). Despite low levels of light and macronutrients (measured in August 2019), observations of juveniles and sori on blades suggests these kelp populations are successfully reproducing and recruiting. Our findings provide information about foundation species and complex marine communities previously unknown to managers of the Galapagos Marine Reserve. They also support the notion that this region is uniquely important for harboring brown macroalgal diversity. Our study highlights critical knowledge gaps on the distribution of primary foundation species in colder mesophotic zones, and how their invisibility from the surface prevents their inclusion in current conservation strategies.