Experimental evidence of uncertain future of the keystone ragworm Hediste diversicolor (OF Muller, 1776) under climate change conditions
Experimental evidence of uncertain future of the keystone ragworm Hediste diversicolor (OF Muller, 1776) under climate change conditions
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DOI：
10.1016/j.scitotenv.2020.142031
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发表时间：
2021-01-01
影响因子：
9.8
通讯作者：
Conradi, Mercedes
中科院分区：
文献类型：
--
作者：
Alam Bhuiyan, Khurshid;Rodriguez, Belen Marin;Conradi, Mercedes
目前认为，与气候变化有关的因素对生物多样性的维持构成了严峻的挑战。本文评估了高温的多应激效应（15摄氏度为对照，25摄氏度为升高）和二氧化碳水平（pH 8.1作为对照，7.5和7.0代表酸化条件）对生理pH的影响。（生存和再生能力），行为（摄食和挖洞活动）和生化变化（代谢能力，氧化状态和生物转化机制）经历的关键多毛类Hediste杂色。温度升高使海水酸化对H. diversicolor，推迟了挖洞活动的开始，增强了pH降低对该多毛类动物挖洞行为的负面影响。此外，无论温度如何，H.酸化导致了摄食率的降低。这是第一次发现这种摄食能力的下降与海水酸化有关。这两种气候因素阻碍了多毛纲动物的再生过程，从而延缓了伤口的愈合和芽基的形成。H.变色龙可能与气候变化条件引起的氧化应激有关，因为自由基的过度产生会损害细胞功能，影响物种的生物化学和生理表现，包括摄食和组织再生。目前的结果还表明，虽然多毛类动物的代谢能力在胁迫条件下增强，生物体仍然能够增加或维持其能量储备。考虑到预测的气候变化条件将影响物种的生命力以及生态和生理能力，我们的研究结果具有重大的环境相关性。这不仅可以转化为个体和种群层面的萎缩，而且可以转化为微生物和底栖动物的退化、河口的碎屑处理以及生态系统层面的生物地球化学循环的萎缩。从而证明了H.杂色种群对河口泥滩生态系统的正常运作至关重要。(C)2020爱思唯尔B.V.保留所有权利。
It is currently assumed that climate change related factors pose severe challenges to biodiversity maintenance. This paper assesses the multi-stressor effects of elevated temperature (15 degrees C as control, 25 degrees C as elevated) and CO2 levels (pH 8.1 as control, 7.5 and 7.0 representing acidifying conditions) on the physiological (survival and regenerative capacity), behavioral (feeding and burrowing activities), and biochemical changes (metabolic capacity, oxidative status and biotransformation mechanisms) experienced by the keystone polychaete Hediste diversicolor. Temperature rise enlarged the adverse effect of marine acidification on the survival of H. diversicolor, delayed the beginning of the excavation activity, enhancing the negative effects that pH decrease had in the burrowing behavior of this polychaete. Additionally, regardless of the temperature, exposure of H. diversicolor to acidification results in a reduction in the feeding rate. It is the first time that this decreased feeding capacity is found related to seawater acidification in this species. The healing of the wound and the blastemal formation were retarded due to these two climatic factors which hinder the regenerative process of polychaetes. These vital physiological functions of H. diversicolor can be related to the oxidative stress induced by climate change conditions since free radicals overproduced will impair cells functioning, affecting species biochemical and physiological performance, including feeding and tissue regeneration. The present results also demonstrated that although polychaetes' metabolic capacity was enhanced under stress conditions, organisms were still able to increase or maintain their energy reserves. Our findings are of major environmental relevance considering that predicted climate change conditions will affect species vital and ecological and physiological capacities. These can be translated into shrinking not only at the individual and population level but also in microbial and endofaunal diversities, in the detritus processing in estuaries and biogeochemical cycles at the ecosystem level. Thus the conservation of H. diversicolor populations is vital for the normal functioning of estuarine mudflat ecosystems. (C) 2020 Elsevier B.V. All rights reserved.