Climate change and disease: bleaching of a chemically defended seaweed
Climate change and disease: bleaching of a chemically defended seaweed
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DOI：
10.1111/j.1365-2486.2011.02456.x
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发表时间：
2011-09-01
影响因子：
11.6
通讯作者：
Steinberg, Peter D.
中科院分区：
文献类型：
--
作者：
Campbell, Alexandra H.;Harder, Tilmann;Steinberg, Peter D.
由于环境变化对寄主生物及其病原体的影响，疾病正在成为全球气候变化的重要影响。气候介导的疾病可能会对自然系统产生严重后果，特别是当生态系统工程师，如栖息地形成者或顶级捕食者受到影响时，因为任何影响都可能级联到整个食物网。在温带海洋生态系统中，海藻是岩礁上的主要栖息地形成者。我们调查了一种可能影响Delisea Pulchra的漂白疾病，Delisea Pulchra是一种化学防御的海藻，发生在全球变暖的“热点”内，并评估了这种现象的模式如何受到海洋温度、太阳辐射、藻类化学防御和微生物病原体的影响。在海藻种群中，较温暖的水域与较高的漂白频率一致且呈正相关，但漂白模式并不总是受光照水平的影响。与健康的菌落相比，漂白的藻体具有较低的抗菌化学防御水平，这在部分漂白的藻类的整个菌体中都可以观察到。与漂白藻类相关的微生物群落与健康海藻表面的微生物群落截然不同。对藻类化学防御的重要性的直接测试是在这里进行的，这是第一次在野外进行，证明它们可以保护海藻免受漂白。用抗生素处理藻体可以降低实验藻类的漂白程度，特别是在水温较高的情况下。这些结果表明，杜鹃花的漂白是温度介导的细菌感染的结果，并突出了变暖通过胁迫宿主来影响疾病动态的可能性。了解全球变化可能影响形成栖息地的海藻等重要生物的复杂方式，对于管理和保护自然资源至关重要。
Disease is emerging as an important impact of global climate change, due to the effects of environmental change on host organisms and their pathogens. Climate-mediated disease can have severe consequences in natural systems, particularly when ecosystem engineers, such as habitat-formers or top predators are affected, as any impacts can cascade throughout entire food webs. In temperate marine ecosystems, seaweeds are the dominant habitat-formers on rocky reefs. We investigated a putative bleaching disease affecting Delisea pulchra, a chemically defended seaweed that occurs within a global warming 'hot-spot' and assessed how patterns of this phenomenon were influenced by ocean temperature, solar radiation, algal chemical defences and microbial pathogens. Warmer waters were consistently and positively correlated with higher frequencies of bleaching in seaweed populations, but patterns of bleaching were not consistently influenced by light levels. Bleached thalli had low levels of antibacterial chemical defences relative to healthy conspecifics and this was observed across entire thalli of partially bleached algae. Microbial communities associated with bleached algae were distinct from those on the surfaces of healthy seaweeds. Direct testing of the importance of algal chemical defences, done here for the first time in the field, demonstrated that they protected the seaweed from bleaching. Treatment of algal thalli with antibiotics reduced the severity of bleaching in experimental algae, especially at high water temperatures. These results indicate that bleaching in D. pulchra is the result of temperature-mediated bacterial infections and highlight the potential for warming to influence disease dynamics by stressing hosts. Understanding the complex ways in which global change may affect important organisms such as habitat-forming seaweeds, is essential for the management and conservation of natural resources.