Sea urchins in a high-CO2 world: partitioned effects of body size, ocean warming and acidification on metabolic rate
Sea urchins in a high-CO2 world: partitioned effects of body size, ocean warming and acidification on metabolic rate
复制标题
DOI：
10.1242/jeb.136101
复制
发表时间：
2016-04-15
影响因子：
2.8
通讯作者：
Byrne, Maria
中科院分区：
文献类型：
--
作者：
Carey, Nicholas;Harianto, Januar;Byrne, Maria
体型和温度是解释代谢率的主要因素，pH的附加因素是生化水平的主要驱动因素。这三个因素经常被发现相互作用，使预测代谢率和生态功能的广泛模型的制定变得复杂。在这项关于变暖和海洋酸化的影响及其潜在相互作用对大范围身体大小(体重相差两到三个数量级)代谢率的第一项研究中，我们结合海洋变暖热点--澳大利亚东南部的气候预测，讨论了气候变化对海胆海胆的影响。海胆被逐渐引入两种温度(18和23摄氏度)和两种PH值水平(7.5和8.0)，并在此条件下保持2个月。相隔几周的相同的实验试验证实了这样一个事实，即已经达到了一种新的生理稳定状态，也就是所谓的驯化。体型、温度和酸化程度对红纹夜蛾代谢率的影响关系非常稳定。两种应激源都导致代谢率增加：温度为20%，pH为19%。综合效应是相加的：新陈代谢增加了44%。体型与代谢率呈高度稳定的关系，与温度和pH无关。这些不同的新陈代谢驱动因素都没有相互作用或调节其他因素的影响，突出了每种因素如何影响代谢率的分区性质，以及实现完全适应状态的重要性。尽管能量需求增加了，但补偿调节摄食率的能力非常有限；食物消耗量只在最小的样本中增加，而且只对温度做出反应，而不是对pH值做出反应。我们的数据显示，变暖、酸化和身体大小都会对新陈代谢产生实质性的影响，而且它们的影响是高度一致的，而且它们的影响是有区别的。对于红蜘蛛来说，在不久的将来，气候变化将带来巨大的能量成本。
Body size and temperature are the major factors explaining metabolic rate, and the additional factor of pH is a major driver at the biochemical level. These three factors have frequently been found to interact, complicating the formulation of broad models predicting metabolic rates and hence ecological functioning. In this first study of the effects of warming and ocean acidification, and their potential interaction, on metabolic rate across a broad range in body size (two to three orders of magnitude difference in body mass), we addressed the impact of climate change on the sea urchin Heliocidaris erythrogramma in context with climate projections for southeast Australia, an ocean warming hotspot. Urchins were gradually introduced to two temperatures (18 and 23 degrees C) and two pH levels (7.5 and 8.0), at which they were maintained for 2 months. Identical experimental trials separated by several weeks validated the fact that a new physiological steady state had been reached, otherwise known as acclimation. The relationship between body size, temperature and acidification on the metabolic rate of H. erythrogramma was strikingly stable. Both stressors caused increases in metabolic rate: 20% for temperature and 19% for pH. Combined effects were additive: a 44% increase in metabolism. Body size had a highly stable relationship with metabolic rate regardless of temperature or pH. None of these diverse drivers of metabolism interacted or modulated the effects of the others, highlighting the partitioned nature of how each influences metabolic rate, and the importance of achieving a full acclimation state. Despite these increases in energetic demand there was very limited capacity for compensatory modulating of feeding rate; food consumption increased only in the very smallest specimens, and only in response to temperature, and not pH. Our data show that warming, acidification and body size all substantially affect metabolism and are highly consistent and partitioned in their effects, and for H. erythrogramma, near-future climate change will incur a substantial energetic cost.