色彩斑斓的珊瑚，可能正在召唤重要的藻类返回家园

色彩斑斓的珊瑚，可能正在召唤重要的藻类返回家园

One of the ways coral reacts to abnormal sea temperatures is by expelling tiny algae that lives in its tissues, a process that drives the type of bleaching events that have devastated Australia’s Great Barrier Reef in recent years. But not all corals respond by turning ghostly white, with some instead becoming shimmering arrays of bright neon colors. The authors of a new study believe this is an attempt to lure the much-needed algae back home.

珊瑚对异常海水温度的反应方式之一是驱逐生活在其组织中的微小藻类，这一过程导致了近年来破坏澳大利亚大堡礁的漂白现象。但并不是所有的珊瑚都会变成幽灵般的白色，有些甚至会变成闪烁的霓虹灯阵列。一项新研究的作者认为，这是一种试图将急需的藻类吸引回家的尝试。

A lot of the coral species that make up structures like Australia’s Great Barrier Reef survive by way of a delicate symbiotic relationship with this algae, which shelter in their cells and provides them with energy via photosynthesis. When sea temperatures rise, it causes this relationship to break down, with the algae abandoning their homes to leave the coral white, withering and in danger of dying.

构成澳大利亚大堡礁等结构的许多珊瑚物种，都是通过与这种藻类微妙的共生关系存活下来的。这种藻类栖息在它们的细胞中，通过光合作用为它们提供能量。当海水温度上升时，这种关系就会破裂，藻类会离开它们的家园，留下白色的珊瑚，枯萎并有死亡的危险。

In what has been a mystery to scientists, however, some of these algae-free coral respond by exhibiting a variety of bright colors instead. To study this phenomenon, scientists at the University of Southampton conducted laboratory experiments at their coral aquarium facility, through which they found these corals produce a type of protective “sunscreen” layer that presents as these colorful displays.

然而，对科学家来说，这一直是个谜，一些没有藻类的珊瑚反而表现出各种明亮的颜色。为了研究这一现象，南安普敦大学的科学家们在珊瑚水族馆进行了实验室实验，他们发现这些珊瑚会产生一种保护性的“防晒”层，就像这些五颜六色的展品一样。

This is a consequence of a business as usual approach on part of the corals, the team found. In the absence of the all-important algae to absorb light, it bounces around inside the coral tissue to give it its white appearance, But when these corals are able to continue some of their normal functions, this internal light instead boosts the production of colorful photoprotective pigments, which act a lure for the returning algae.

研究小组发现，这是部分珊瑚礁照常工作的结果。在没有最重要的藻类来吸收光的情况下，它会在珊瑚组织内反弹，使珊瑚呈现出白色的外观，但当这些珊瑚能够继续发挥部分正常功能时，这种内部光线反而会促进彩色的光保护色素的产生，这些色素对返回的藻类起到了诱导作用。

“The resulting sunscreen layer will subsequently promote the return of the symbionts,” says Professor Jörg Wiedenmann, head of the University of Southampton’s Coral Reef Laboratory. “As the recovering algal population starts taking up the light for their photosynthesis again, the light levels inside the coral will drop and the coral cells will lower the production of the colorful pigments to their normal level.”

南安普敦大学珊瑚礁实验室负责人Júrg Wiedemann教授说：“由此产生的防晒层随后将促进共生体的回归。”。“随着恢复中的藻类种群开始重新吸收光进行光合作用，珊瑚体内的光照水平将下降，珊瑚细胞将把彩色色素的产生降低到正常水平。”

The scientists believe that corals exhibiting this behavior have most likely experienced mild or short-lived warming events, rather than the type of extreme and drawn-out temperature rises that threaten much of the world’s reefs.

科学家们认为，表现出这种行为的珊瑚最有可能经历温和或短暂的变暖事件，而不是威胁到世界许多珊瑚礁的那种极端和持久的升温。

“Bleaching is not always a death sentence for corals, the coral animal can still be alive,” says Dr Cecilia D’Angelo, Lecturer of Molecular Coral Biology at the University of Southampton. “If the stress event is mild enough, corals can re-establish the symbiosis with their algal partner. Unfortunately, recent episodes of global bleaching caused by unusually warm water have resulted in high coral mortality, leaving the world’s coral reefs struggling for survival.”

南安普敦大学分子珊瑚生物学讲师塞西莉亚·迪安杰洛博士说:“珊瑚白化并不总是对珊瑚宣判死刑，珊瑚动物仍然可以存活。”“如果压力事件足够轻微，珊瑚可以重建与藻类伙伴的共生关系。”不幸的是，最近异常温暖的海水导致全球珊瑚白化，导致珊瑚死亡率很高，世界各地的珊瑚礁都在为生存而挣扎。”