Morais Renato A, Patricio-Valerio Larissa, Narvaez Pauline, Parravicini Valeriano, Brandl Simon J
Université Paris Sciences et Lettres, CRIOBE-UAR3278, Avenue Paul Alduy, Perpignan 66100, France.
Central Queensland University, Coastal Marine Ecosystems Research Centre, Alf Orourke Dr., Callemondah, Gladstone, QLD 4680, Australia.
Curr Biol. 2025 Jul 7;35(13):3241-3250.e6. doi: 10.1016/j.cub.2025.05.033. Epub 2025 Jun 5.
Coral reefs are frequently described as "oases in marine deserts" for thriving in nutrient-depleted oceans. This contrast is often termed "Darwin's paradox," which allegedly originates from Charles Darwin's coral reef work. Decades of research exploring these paradoxical dynamics led to groundbreaking findings in ecophysiology, ecology, oceanography, and biogeochemistry. However, the historical foundations and scientific generality of the paradox remain unevaluated. Here, we demonstrate that Darwin's paradox is a misnomer. Indeed, the fundamental knowledge required to formulate this idea did not exist at the time of Darwin's 1842 coral reef treatise: its earliest references date, instead, to the 1940s-1950s. Given the frequent use of the term, and the "marine oasis" analogy, which implies high productivity despite nutrient-poor waters as a hallmark of reefs worldwide, we (1) compare reef productivity across ecosystems and (2) assess how globally widespread oligotrophic, low-nutrient reef conditions are. Our findings support earlier work placing coral reefs among the most productive ecosystems on Earth. However, relatively few coral reefs exist in oligotrophic waters; 80% of them occur in more productive mesotrophic and eutrophic conditions. Globally, median chlorophyll-a near reefs is 0.19 mg m, twice the median for tropical oceans and double the upper oligotrophic threshold. Reefs range across the tropical ocean spectrum of phosphate, nitrate, iron, and silicate concentrations but are disproportionally common in moderate levels of these vital nutrients. Thus, coral reefs as oases in marine deserts are not the norm, highlighting the need to recognize environmental variability and both intrinsic and extrinsic pathways sustaining reef productivity.
珊瑚礁常被描述为“海洋沙漠中的绿洲”，因为它们能在营养物质匮乏的海洋中蓬勃生长。这种反差常被称为“达尔文悖论”，据说它源于查尔斯·达尔文对珊瑚礁的研究。数十年来，对这些矛盾动态的研究在生态生理学、生态学、海洋学和生物地球化学领域取得了开创性的发现。然而，这一悖论的历史基础和科学普遍性仍未得到评估。在这里，我们证明“达尔文悖论”是一个误称。事实上，形成这一观点所需的基础知识在达尔文1842年关于珊瑚礁的论文发表时并不存在：它最早的参考文献反而可以追溯到20世纪40年代至50年代。鉴于该术语的频繁使用以及“海洋绿洲”这一比喻，即尽管海水营养匮乏，但高生产力是全球珊瑚礁的一个标志，我们（1）比较了不同生态系统中珊瑚礁的生产力，（2）评估了贫营养、低营养的珊瑚礁条件在全球的普遍程度。我们的研究结果支持了早期的研究，即把珊瑚礁列为地球上生产力最高的生态系统之一。然而，贫营养水域中的珊瑚礁相对较少；其中80%出现在生产力较高的中营养和富营养环境中。在全球范围内，珊瑚礁附近叶绿素-a的中位数为0.19毫克/立方米，是热带海洋中位数的两倍，也是贫营养上限的两倍。珊瑚礁分布在热带海洋中磷酸盐、硝酸盐、铁和硅酸盐浓度的整个范围内，但在这些重要营养物质的中等水平上分布尤为普遍。因此，珊瑚礁作为海洋沙漠中的绿洲并非常态，这凸显了认识环境变异性以及维持珊瑚礁生产力的内在和外在途径的必要性。
