Natural stable isotopes of iron: a new tool to trace Fe cycling for management of risk from harmful cyanobacterial blooms in lakes and reservoirs

铁的天然稳定同位素：追踪铁循环的新工具，用于管理湖泊和水库有害蓝藻水华的风险

• 批准号: 494497-2016
• 负责人: Schiff, Sherry
• 金额: $ 16.55万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Strategic Projects - Group
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=641986
• 关键词: Natural; stable; isotopes; iron; new

Harmful algal blooms in lakes and reservoirs constitute a major threat to human health and, by extension, to all aspects of the Canadian economy. Harmful algal blooms (HABs), especially those associated with cyanobacteria (cyano-HABs) have direct impacts on the safety of drinking water supplies by producing a variety of liver and nerve toxins in addition to causing taste and odour problems. Cyano-HABs have been increasing in recent years across Canada from Newfoundland to British Columbia. Causes of this increase are unknown but various exacerbating effects have been suggested, among these are changes in nutrients, a decrease in acid precipitation and climate change. There is an urgent need to evaluate the science and to manage risk with regard to cyano-HABs. Inputs of the main nutrients, phosphorus (P) and nitrogen (N), have been the focus of much research and management effort. Recently a new theory centres on the importance of the availability of iron (Fe) in the form of Fe(II) as the key to cyanobacterial blooms. Determining the source of Fe(II) available to cyanobacteria is, however, problematic. Fe is low in surface waters because Fe(III) is very insoluble and oxygen quickly changes Fe(II) to Fe(III). We have discovered that the natural stable isotopes of Fe hold great promise to decipher the source of Fe used by cyanobacteria. Our project will evaluate this novel isotopic tool for understanding Fe cycling in lakes and reservoirs at risk from cyano-HABs. The work will be focussed at the Experimental Lakes Area (ELA) where background information on chemistry, biology and physics of lakes has been collected over the past 47 years. One of the key components is the intensive research ongoing at a globally unique whole lake experiment where one lake has received nutrient additions for 47 years and has recurring cyanobacterial blooms. A series of field campaigns at ELA and laboratory experiments will evaluate the use of natural stable Fe isotopes. In addition, carefully selected samples from other lakes and reservoirs across Canada, collected by collaborating scientists, will be analyzed to evaluate the potential for widespread application of this promising novel technique.

湖泊和水库中有害的藻华对人类健康构成重大威胁，进而对加拿大经济的各个方面构成重大威胁。有害藻华 (HAB)，尤其是与蓝藻相关的藻华 (cyano-HAB)，除了引起味道和气味问题外，还产生各种肝脏和神经毒素，对饮用水供应的安全产生直接影响。近年来，从纽芬兰到不列颠哥伦比亚省，加拿大各地的氰基有害细菌不断增加。这种增加的原因尚不清楚，但有人提出了各种加剧影响，其中包括营养物质的变化、酸降水的减少和气候变化。迫切需要对氰基有害细菌进行科学评估并管理风险。主要养分磷（P）和氮（N）的输入一直是许多研究和管理工作的重点。最近，一项新理论的重点是以 Fe(II) 形式提供铁 (Fe) 的重要性，作为蓝藻水华的关键。然而，确定蓝藻可用的 Fe(II) 来源是有问题的。地表水中的 Fe 含量较低，因为 Fe(III) 非常难溶，氧气很快会将 Fe(II) 转变为 Fe(III)。我们发现，Fe 的天然稳定同位素有望破译蓝藻细菌使用的 Fe 来源。我们的项目将评估这种新型同位素工具，以了解面临氰基 HAB 风险的湖泊和水库中的铁循环。这项工作将集中在实验湖泊区 (ELA)，该区在过去 47 年里收集了有关湖泊化学、生物学和物理学的背景信息。其中一个关键组成部分是一项全球独一无二的全湖实验正在进行的深入研究，其中一个湖泊已经接受了 47 年的营养添加，并且经常出现蓝藻水华。 ELA 的一系列现场活动和实验室实验将评估天然稳定铁同位素的使用。此外，合作科学家将从加拿大其他湖泊和水库中精心挑选的样本进行分析，以评估这种有前景的新技术广泛应用的潜力。