Cold-water carbonate production in Canadian waters.

加拿大水域的冷水碳酸盐生产。

• 批准号: RGPIN-2014-04826
• 负责人: Edinger, Evan
• 金额: $ 2.19万
• 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: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611267
• 关键词: Cold; water; carbonate; production; Canadian

This project studies cold-water carbonate sediments in Canadian waters, and the marine plants and animals that make those sediments. Cool-water carbonate sediments can accumulate in non-tropical environments such as temperate and even polar continental shelves. Most Canadian waters fall into the coldest-water carbonate realm, but cold-water carbonate sediments in Canada have received little previous study, unlike well-studied regions like the southern Australian shelf, the Mediterranean Sea, or the Northwestern European continental margin. Many of the organisms that make these sediments, such as calcareous algae, bryozoans, barnacles, and cold-water corals, may be ecologically important in creating or structuring habitat for other invertebrates and fishes. Like tropical reefs, these biologically produced habitats, and the carbonate sediments they make, accumulate in a fine balance between carbonate production by organisms, and carbonate loss through biological erosion and dissolution. This balance is most fragile in the polar carbonate realm, where cold waters are corrosive, promoting dissolution, and biological erosion is generally fast. Carbonate systems are subject to at least two important anthropogenic threats: ocean acidification, and physical damage from bottom-contact fishing. These recent anthropogenic threats may push cold-water carbonates into net erosion and carbonate loss, similar to the geological consequences of ecological decline on tropical coral reefs. This research will assess the importance of the cold-water or polar carbonate system in Canadian waters, characterizing its composition, and measuring the balance between gross carbonate production and carbonate loss through bioerosion, fragmentation, and dissolution. This research will determine how the balance between production and loss varies by location and depth in Canadian waters, as a function of regional oceanography. The variation in rates of carbonate production by various skeletal organisms, such as bryozoans, barnacles, calcareous algae, and cold-water corals will be assessed. Since carbonate loss by dissolution and bioerosion are important drivers of the balance, this research program will also characterize rates of bioerosion and dissolution of the most abundant carbonate skeleton types, and how those rates vary. Field experiments on carbonate loss through bioerosion and dissolution will be deployed at various depths in waters of both Newfoundland and British Columbia. BC experiments will be deployed at the NEPTUNE cabled oceanographic observatory gas hydrates site within the oxygen minimum zone, where we have observed abundant deep-sea corals. Finally, we will assess the impacts of ocean acidification on both carbonate production and carbonate loss. Growth and breakdown experiments under laboratory conditions simulating ocean acidification in the deep sea will predict the impact of anthropogenic increases in atmospheric carbon dioxide concentrations on cold-water carbonate production and carbonate destruction in deep water environments. This research program will clarify the geological, biological, and oceanographic importance of the cold-water carbonate realm in Canada, and highlight similarities and differences between non-tropical carbonates in Canada and other regions of the world. Knowing where in Canadian waters the most sensitive biota and greatest net carbonate production occur will be important for habitat conservation, particularly as decreasing sea ice coverage in the Arctic makes more areas accessible to commercial fishing. Predicting the sensitivity of polar carbonate producing organisms to ocean acidification, will help determine how fragile or resilient polar carbonate systems are with respect to global climate change.

该项目研究加拿大水域的冷水碳酸盐沉积物，以及形成这些沉积物的海洋植物和动物。冷水碳酸盐沉积物可以在非热带环境中积累，例如温带甚至极地大陆架。大多数加拿大水域属于最冷的碳酸盐区域，但与澳大利亚南部陆架、地中海或西北欧大陆边缘等经过充分研究的地区不同，加拿大的冷水碳酸盐沉积物之前很少受到研究。形成这些沉积物的许多生物体，例如钙质藻类、苔藓虫、藤壶和冷水珊瑚，在为其他无脊椎动物和鱼类创造或构建栖息地方面可能具有重要的生态意义。与热带珊瑚礁一样，这些生物产生的栖息地及其形成的碳酸盐沉积物在生物产生的碳酸盐与生物侵蚀和溶解造成的碳酸盐损失之间保持着良好的平衡。这种平衡在极地碳酸盐领域最为脆弱，那里的冷水具有腐蚀性，促进溶解，而且生物侵蚀通常很快。碳酸盐系统至少受到两个重要的人为威胁：海洋酸化和海底接触捕鱼造成的物理损害。最近的这些人为威胁可能会将冷水碳酸盐推向净侵蚀和碳酸盐流失，类似于热带珊瑚礁生态衰退的地质后果。 这项研究将评估加拿大水域冷水或极性碳酸盐系统的重要性，表征其组成，并测量碳酸盐总产量和生物侵蚀、破碎和溶解造成的碳酸盐损失之间的平衡。这项研究将确定产量和损失之间的平衡如何随加拿大水域的位置和深度而变化，作为区域海洋学的函数。将评估各种骨骼生物（例如苔藓虫、藤壶、钙质藻类和冷水珊瑚）碳酸盐生成速率的变化。由于溶解和生物侵蚀造成的碳酸盐损失是平衡的重要驱动因素，因此该研究计划还将表征最丰富的碳酸盐骨架类型的生物侵蚀和溶解速率，以及这些速率如何变化。关于生物侵蚀和溶解造成的碳酸盐损失的现场实验将在纽芬兰和不列颠哥伦比亚省水域的不同深度进行。 BC 实验将部署在海王星有线海洋观测站天然气水合物地点，该地点位于最低氧区内，我们在那里观察到了丰富的深海珊瑚。 最后，我们将评估海洋酸化对碳酸盐产生和碳酸盐损失的影响。在模拟深海海洋酸化的实验室条件下进行的生长和分解实验将预测大气二氧化碳浓度的人为增加对深水环境中冷水碳酸盐生成和碳酸盐破坏的影响。 该研究计划将阐明加拿大冷水碳酸盐区的地质、生物和海洋学重要性，并强调加拿大和世界其他地区非热带碳酸盐岩之间的异同。了解加拿大水域中最敏感的生物群和最大的净碳酸盐产生量对于栖息地保护非常重要，特别是因为北极海冰覆盖范围的减少使得更多地区可以进行商业捕鱼。预测产生极性碳酸盐的生物体对海洋酸化的敏感性，将有助于确定极性碳酸盐系统对全球气候变化的脆弱性或弹性。