Northern North Atlantic biogenic habitat calcium carbonate production: geographic variation and vulnerability to climate change

北大西洋北部生物栖息地碳酸钙生产：地理变化和气候变化脆弱性

• 批准号: RGPIN-2020-04183
• 负责人: Edinger, Evan
• 金额: $ 2.62万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754783
• 关键词: Northern; North; Atlantic; biogenic; habitat

Calcareous algae and cold-water corals are habitat-forming organisms that produce calcium carbonate skeletons in the cold-water environments of the North Atlantic. Their ability to build skeletons, and for those skeletons to endure after the algae or corals have died, is crucial for their ability to form habitats and produce calcium carbonate sediments. Ocean acidification threatens skeleton formation, and especially the ability of skeletons to make a habitat that will remain after the algae or corals are dead.   Calcareous algae, and the calcareous soft corals that inhabit the cold waters of eastern Canada are particularly vulnerable to ocean acidification because their skeletons are composed of high-magnesium calcite. The goal of this research is to understand the current and predicted impacts of ocean acidification on the habitats formed by calcareous algae and cold-water corals. This research program will compare skeleton formation, post-mortem skeleton loss, and carbonate production across the natural ocean acidification gradient between the Northwest Atlantic (Canada, specifically Newfoundland and Labrador, and the Eastern Canadian Arctic) and the Northeast Atlantic (N Europe, specifically NW France). Furthermore, this research will examine the history of calcareous algae and cold-water coral-based ecosystems over the last several hundred to several thousand years. Sediment cores will be collected and analyzed from calcareous algae and cold-water coral habitats on soft bottoms to reveal how these habitats have evolved in relation to changing oceanographic or climatic conditions or changes in coastal land use.  In hard-bottom environments, we will use the chemistry of the calcareous algae or cold-water coral skeletons to reveal the records of past climatic or oceanographic conditions.  Pressurized aquarium experiments on dissolution of calcareous algae or cold-water coral skeletons under high CO2 conditions predicted under emissions reduction targets or business-as-usual will measure the response of cold-water coral skeletons to acidified deep oceans. Calcareous algae, especially unattached algae called rhodoliths, and cold-water corals are already threatened by direct impacts of human activities, such as bottom-contact fishing. Understanding and predicting their fate in relation to climate change and ocean acidification will help protect these habitats in the long term. The ability of rhodolith beds and cold-water coral forests to host other biodiversity depends partly on their ability to maintain a positive net carbonate budget, that is, to be producing more calcium carbonate skeletons and sediment than the carbonate lost to dissolution, biological erosion, and sediment export.    Hosting biodiversity supports fisheries.  Understanding the effects of ocean acidification on carbonate biogenic habitats will help protect biodiversity and sustainable fisheries in Atlantic and Northern Canada.

钙质藻类和冷水珊瑚是在北大西洋冷水环境中产生碳酸钙骨架的生境形成生物。它们建造骨骼的能力，以及这些骨骼在藻类或珊瑚死亡后的生存能力，对于它们形成栖息地和产生碳酸钙沉积物的能力至关重要。海洋酸化威胁着骨骼的形成，特别是骨骼在藻类或珊瑚死亡后形成栖息地的能力。 生活在加拿大东部寒冷沃茨的钙质藻类和钙质软珊瑚特别容易受到海洋酸化的影响，因为它们的骨骼是由高镁方解石组成的。这项研究的目的是了解海洋酸化对钙质藻类和冷水珊瑚形成的栖息地的当前和预测影响。这项研究计划将比较西北大西洋（加拿大，特别是纽芬兰和拉布拉多，以及加拿大东部北极地区）和东北大西洋（北欧，特别是法国西北部）之间的自然海洋酸化梯度的骨骼形成，死后骨骼损失和碳酸盐生产。 此外，这项研究将研究石灰藻类和冷水珊瑚生态系统在过去几百到几千年的历史。将从软底的石灰藻类和冷水珊瑚生境中收集和分析沉积物芯，以揭示这些生境是如何随着海洋学或气候条件的变化或沿海土地使用的变化而演变的。我们将利用钙质藻类的化学性质水珊瑚骨骼，揭示过去的气候或海洋条件的记录。加压水族馆实验的溶解石灰质藻类或冷，根据减排目标或“一切照旧”预测的高二氧化碳条件下的水珊瑚骨骼将衡量冷水珊瑚骨骼对深海酸化的反应。钙质藻类，特别是被称为红藻的独立藻类，以及冷水珊瑚已经受到人类活动的直接影响的威胁，例如触底捕鱼。了解和预测它们与气候变化和海洋酸化的关系将有助于长期保护这些栖息地。红岩床和冷水珊瑚林容纳其他生物多样性的能力部分取决于它们维持正的碳酸盐净收支的能力，也就是说，产生的碳酸钙骨架和沉积物多于溶解、生物侵蚀和沉积物输出所损失的碳酸盐。 了解海洋酸化对碳酸盐生物栖息地的影响将有助于保护大西洋和加拿大北方的生物多样性和可持续渔业。