Responses of calcifying macroalgae to ocean acidification

海洋酸化导致碳酸盐饱和度和海水pH值迅速下降，对所有海洋生物都有潜在的后果。这个博士项目的重点是珊瑚红藻及其相关生物膜的反应。这些至关重要的钙化巨藻(CM)是关键的初级生产者，主导着从极地到热带珊瑚礁到200米深的坚硬表面，是许多无脊椎动物的生态工程师。它们产生了高镁方解石的骨架，这使得它们对当前海洋化学的变化特别敏感。相关生物膜对珊瑚藻类生长的影响及其对海洋酸化的反应尚不清楚。本项目的目的是通过提出以下问题来量化CMS对海洋酸化的响应：不受人为排放影响的CM材料是否表现出与新鲜材料不同的骨骼形态？2.由于不同水平的光氧化应激，CM的生长速度是否会沿着纬度梯度变化？3.海洋酸化是否会通过下调/抑制生产力来加剧CMS的光氧化应激水平？4.大型藻类及其主要非钙化生物膜之间的平衡是否会因OA而改变？该项目汇集了珀金斯博士(加的夫大学)、亚洛普博士(布里斯托尔大学)和布罗迪教授(NHM，案例合作伙伴)，这是一个在微型和大型藻类光生理学、分子生物学和大型藻类全球分布方面拥有专业知识的财团。还将与Bartsch博士合作(AWI不来梅港；BIOACID项目)。由于实地考察地点横跨大西洋东北部的纬度梯度，PHD将结合实验室和实地研究，包括分子技术、骨骼形态检查、光合作用和荧光测量以及比较生长模式，以解决提出的问题。

The rapid reduction in carbonate saturation and seawater pH caused by ocean acidification has potential consequences for all marine biota. This PhD project focuses on the responses of coralline red algae and their associated biofilms. These critically important calcifying macroalgae (CM) are key primary producers, dominate hard surfaces from polar to tropical coral reefs to > 200 m deep, and are ecosystem engineers providing a substratum for many invertebrates. They produce a skeleton of high-Mg calcite which makes them particularly sensitive to the current changes in ocean chemistry. The effect of the associated biofilm on the growth of coralline algae and its response to ocean acidification is unknown. The aim of this project is to quantify the response of CMs to ocean acidification by asking the following questions: Does CM material not impacted by anthropogenic emissions exhibit a different skeletal morphology to fresh material? 2. Will CM growth rate vary along a latitudinal gradient due to different levels of photo-oxidative stress? 3. Will ocean acidification exacerbate the level of photo-oxidative stress in CMs by down regulated/inhibited productivity? 4. Will the balance between macroalgae and their predominantly non-calcifying biofilms shift as a result of OA? The project brings together Dr Perkins (Cardiff University), Dr Yallop (Bristol University) and Prof. Brodie (NHM, CASE partner), a consortium with expertise in micro- and macroalgal photophysiology, molecular biology and the global distribution of macroalgae. There will also be collaboration with Dr Bartsch (AWI Bremerhaven; BIOACID project). With field sites spanning a latitudinal gradient in the northeast Atlantic, the PhD will combine laboratory and field studies including molecular techniques, examination of skeletal morphology, measurements of photosynthesis and fluorescence, and comparative growth patterns to address the questions posed.