Responses of calcifying macroalgae to ocean acidification

海洋酸化导致的碳酸盐饱和度和海水pH值的迅速降低对所有海洋生物群都有潜在的影响。本博士项目主要研究珊瑚红藻及其相关生物膜的反应。这些至关重要的钙化大型藻类（CM）是主要的初级生产者，从极地到热带珊瑚礁到bb100 - 200米深的坚硬表面，是生态系统工程师，为许多无脊椎动物提供了基质。它们产生的高镁方解石骨架使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生长的影响及其对海洋酸化的响应尚不清楚。该项目的目的是通过提出以下问题来量化CMs对海洋酸化的反应：未受人为排放影响的CM材料是否表现出与新鲜材料不同的骨骼形态？2. 不同的光氧化胁迫水平是否会导致CM生长速率沿纬度梯度变化？3. 海洋酸化是否会通过降低/抑制生产力而加剧CMs中的光氧化应激水平？4. 大型藻类和它们主要的非钙化生物膜之间的平衡会因为OA而改变吗？该项目汇集了Perkins博士（Cardiff University）、Yallop博士（Bristol University）和Brodie教授（NHM， CASE合作伙伴），这是一个在微藻和大藻光生理学、分子生物学和大藻全球分布方面具有专业知识的联盟。还将与Bartsch博士（AWI不来梅港；BIOACID项目）合作。在东北大西洋横跨纬度梯度的现场，博士将结合实验室和现场研究，包括分子技术，骨骼形态检查，光合作用和荧光测量，以及比较生长模式来解决所提出的问题。

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.