Respiratory Acclimation of Marine Fish to Ocean Deoxygenation

海鱼对海洋脱氧的呼吸适应

• 批准号: 2002549
• 负责人: Andrew Esbaugh
• 金额: $ 57.06万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2002549&HistoricalAwards=false
• 关键词: Respiratory; Acclimation; Marine; Fish; Ocean

Anthropogenic factors, including climate change, are increasing the prevalence of low-oxygen zones in oceans around the world (i.e., ocean deoxygenation), and this is especially true in the northern Gulf of Mexico where large seasonal oxygen minimum zones are common. Deoxygenation of coastal waters has serious implications for marine life, including the economically and ecologically important fish species endemic to these regions. It is hypothesized that the long-term survival of species subjected to this type of environmental change depend in part on their ability to acclimate by altering their physiology, a concept known as phenotypic plasticity. This proposal will use a combination of molecular biology, biochemistry, and whole-animal physiology to explore the ability of an economically important fish species, the red drum (Sciaenops ocellatus), to enhance respiratory oxygen uptake following exposure to prolonged periods of reduced oxygen availability. Results of this work will be incorporated into public education initiatives targeting K-12 students. The goal of these efforts will be to increase the scientific literacy of youth and the general public with an emphasis on understanding the core principles of ocean health, climate change, and the importance of healthy oceans and fish populations for coastal communities. In addition, mentored research training in integrative physiology will be provided for several undergraduate and graduate students and a post-doctoral fellow. The primary objective of this work is to explore the physiological mechanisms and ecological significance of respiratory plasticity in a representative marine fish, the red drum, exposed to prolonged environmental hypoxia. These exposures will occur above the critical oxygen threshold for the species, and the capacity of red drum to maximize aerobic scope, which would increase the capacity for ecologically important activities, will be assessed. This work integrates across multiple levels of organization by first exploring plasticity in the red blood cells, heart and red muscle using gene expression and biochemistry, after which whole-animal performance will be measured. The project addresses the following hypotheses related to hypoxia exposure: 1) fish will exhibit an altered pattern of hemoglobin expression coincident with elevated red blood cell and plasma accessible carbonic anhydrase that will work cooperatively to enhance oxygen offloading in the heart and muscle; 2) the heart and muscle will exhibit reduced mitochondrial proton leak, thereby generating more energy per unit oxygen; 3) acclimation will result in increased swimming performance and aerobic scope at the organismal level; 4) red drum exposed to reduced oxygen levels at early life stages will exhibit rigid phenotypic plasticity that results in altered phenotypes later in life. This comprehensive evaluation will provide invaluable insight into the ability of marine fishes to offset the deleterious effects of ocean deoxygenation on respiratory performance. These activities will also contribute to graduate and undergraduate student and post-doctoral training, and results will be integrated into public education initiatives focused on implications of climate change and ocean deoxygenation on marine life. This award was co-funded by the GEO-Division of Ocean Sciences Biological Oceanography Program and the BIO-Division of Integrative Organismal Systems Physiological Mechanisms and Biomechanics Program.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

包括气候变化在内的人为因素正在增加世界各地海洋低氧区的普遍存在（即，海洋脱氧），并且这在墨西哥湾的北方尤其如此，在那里大的季节性氧气最小区是常见的。沿海沃茨的脱氧对海洋生物，包括对这些地区特有的具有经济和生态重要性的鱼种，有着严重的影响。据推测，物种的长期生存受到这种类型的环境变化部分取决于他们的能力，通过改变他们的生理适应，一个概念被称为表型可塑性。该提案将使用分子生物学，生物化学和整体动物生理学的组合，以探索一种经济上重要的鱼类，红鱼（Sciaenops ocellatus），在长时间暴露于氧气供应减少后，提高呼吸氧摄取的能力。这项工作的成果将纳入针对K-12学生的公共教育举措。这些努力的目标是提高青年和公众的科学素养，重点是了解海洋健康、气候变化的核心原则以及健康的海洋和鱼类种群对沿海社区的重要性。此外，将为几名本科生和研究生以及一名博士后研究员提供综合生理学方面的指导研究培训。本研究的主要目的是探讨在长期低氧环境下，红鼓鱼呼吸可塑性的生理机制和生态学意义。这些接触将发生在该物种的临界氧气阈值之上，将评估红鼓最大限度地扩大有氧范围的能力，这将增加进行具有生态重要性的活动的能力。这项工作通过首先利用基因表达和生物化学探索红细胞、心脏和红肌肉的可塑性，整合了多个组织层次，之后将测量整个动物的表现。该项目解决了与缺氧暴露相关的以下假设：1）鱼类将表现出血红蛋白表达的改变模式，与红细胞和血浆可接近的碳酸酐酶的升高相一致，这将协同工作以增强心脏和肌肉中的氧卸载; 2）心脏和肌肉将表现出减少的线粒体质子泄漏，从而每单位氧产生更多的能量; 3）驯化将导致在生物体水平上增加的游泳性能和有氧范围; 4）在生命早期阶段暴露于降低的氧气水平的红鼓将表现出刚性的表型可塑性，导致在以后的生活中改变表型。这项全面的评估将提供宝贵的洞察力海洋鱼类的能力，以抵消海洋脱氧对呼吸性能的有害影响。这些活动还将有助于研究生、本科生和博士后的培训，其成果将纳入以气候变化和海洋脱氧对海洋生物的影响为重点的公共教育举措。 该奖项由GEO海洋科学部生物海洋学计划和生物部综合有机系统生理机制和生物力学计划共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Is hypoxia vulnerability in fishes a by-product of maximum metabolic rate?

• DOI: 10.1242/jeb.232520
• 发表时间: 2021-07-01
• 期刊: JOURNAL OF EXPERIMENTAL BIOLOGY
• 影响因子: 2.8
• 作者: Esbaugh, Andrew J.;Ackerly, Kerri L.;Negrete, Benjamin
• 通讯作者: Negrete, Benjamin

The effects of warming on red blood cell carbonic anhydrase activity and respiratory performance in a marine fish

• DOI: 10.1016/j.cbpa.2021.111033
• 发表时间: 2021-07-14
• 期刊: COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY
• 影响因子: 2.3
• 作者: Dichiera, Angelina M.;Khursigara, Alexis J.;Esbaugh, Andrew J.
• 通讯作者: Esbaugh, Andrew J.

Respiratory plasticity improves aerobic performance in hypoxia in a marine teleost

呼吸可塑性改善海洋硬骨鱼缺氧时的有氧表现

• 发表时间: 2022
• 期刊: Science of the total environment
• 影响因子: 9.8
• 作者: Negrete Jr., B.;Ackerly, K.L.;Dichiera, A.M.;Esbaugh, A.J.
• 通讯作者: Esbaugh, A.J.

Assessment of hypoxia avoidance behaviours in a eurythermal fish at two temperatures using a modified shuttlebox system

• DOI: 10.1111/jfb.14691
• 发表时间: 2021-02-17
• 期刊: JOURNAL OF FISH BIOLOGY
• 影响因子: 2
• 作者: Ern, Rasmus;Esbaugh, Andrew J.
• 通讯作者: Esbaugh, Andrew J.

The effects of size on exhaustive exercise and recovery in a marine sportfish, the red drum (Sciaenops ocellatus)

体型对海洋运动鱼红石首鱼 (Sciaenops ocellatus) 力竭运动和恢复的影响

• 发表时间: 2023
• 期刊: Comparative biochemistry and physiology Part B Biochemistry molecular biology
• 作者: Martin, L.;Negrete Jr., B.;Esbaugh, A.J.
• 通讯作者: Esbaugh, A.J.