Predicting physiological impacts of disturbance on marine mammals: Implications for population-level effects

预测干扰对海洋哺乳动物的生理影响：对种群水平影响的影响

• 批准号: 2906458
• 金额: --
• 依托单位: University of St Andrews
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2906458
• 关键词: Predicting; physiological; impacts; disturbance; marine

The increasing urbanisation of marine environments poses a risk for marine populations. The Population Consequences of Disturbance (PCoD) model is a conceptual modelling framework that aims to predict the mechanistic effects of anthropogenic disturbance on the behaviour and physiology of marine populations, including marine mammals. Currently, the primary metrics for quantifying disturbance are behavioural changes, meaning there is a lack of empirical data to parameterise physiological health consequences in the PCoD model. Marine mammals have specialised anatomical and physiological adaptations to endure long periods of apnoea (i.e. breath-holding) making them sensitive to disturbance, as it could challenge physiological homeostasis and affect their ability to dive, forage, and recover. Previous research suggests that marine mammals may experience a simultaneous fight and flight response following a disturbance event in which oxygen is required for exercise, but the necessary cardiovascular responses to accommodate the oxygen demand do not occur. This paradoxical response may result in hypoxia (low blood oxygen) and hypercapnia (increased carbon dioxide); collectively called asphyxia. Given the limited technological and logistical capabilities for physiological monitoring, the consequences of asphyxia in response to disturbance of marine mammals are unknown. This project aims to inform this knowledge gap by measuring physiological consequences of disturbance to marine mammals and their interaction with behaviour and foraging energetics in order to integrate physiological and health components to population modelling frameworks. The data will be collected using voluntarily diving, temporarily captive, grey seals at the Sea Mammal Research Unit's pool facility, in which seals make repeated dives to a feeder and back to the surface to breathe. The physiological state of the seals will be manipulated without exposing seals to disturbance stimuli by using a breathing chamber to control exposure to respiratory gas mixes: ambient, hypoxic, and hypercapnic. The effect of changing blood gases on (1) cardiovascular regulation and organ function and (2) energetics will be measured using this experimental setup. Cardiovascular function and blood gases will be measured by wearable, non-invasive continuous-wave near infrared spectroscopy (NIRS) tags. Additionally, venous blood sampling before and after diving trails will provide blood biomarkers of mild traumatic brain injury, oxidative stress, and inflammation to be combined with NIRS data to investigate changes to organ and tissue homeostasis. Energy expenditure required to dive and consume prey will be calculated using dive and recovery interval durations, as well as total oxygen consumption and carbon dioxide production calculated from open-flow respirometry. Together, these metrics will allow for testing and calibration of metrics for energy expenditure that can be incorporated into onboard data processing of NIRS tags for future field deployments. Finally, the physiological and energetic outcomes will be incorporated to existing PCoD models to predict individual and population level consequences of disturbance.

海洋环境的城市化日益增加为海洋人群带来风险。干扰（PCOD）模型的人口后果是一个概念建模框架，旨在预测人为障碍对包括海洋哺乳动物在内的海洋种群行为和生理学的机理影响。当前，用于量化干扰的主要指标是行为变化，这意味着缺乏经验数据来参数化PCOD模型中的生理健康后果。海洋哺乳动物具有专门的解剖学和生理适应性，可以忍受长时间的呼吸暂停（即呼吸呼吸），使其对障碍敏感，因为它可能会挑战生理稳态并影响其潜水，觅食和康复的能力。先前的研究表明，在发生运动需要氧气的情况下，海洋哺乳动物可能会同时进行战斗和飞行反应，但是不会发生必要的心血管反应以适应氧气需求。这种矛盾的反应可能导致缺氧（低血氧）和高碳酸盐（二氧化碳增加）；集体称为窒息。鉴于生理监测的技术和后勤能力有限，窒息对海洋哺乳动物干扰的后果尚不清楚。该项目旨在通过衡量对海洋哺乳动物的疾病的生理后果以及它们与行为和觅食能量学的相互作用来告知这一知识差距，以便将生理和健康组成部分整合到人群建模框架中。数据将使用自愿潜水，暂时俘虏的灰密封在海洋哺乳动物研究单元的泳池设施中，其中密封件可重复潜入进料器，然后回到表面以呼吸。密封的生理状态将通过使用呼吸室来控制暴露于呼吸道气体的情况下，而不会暴露密封剂对干扰刺激：环境，低氧和高含量。更换血液对（1）心血管调节和器官功能以及（2）能量学的影响将使用此实验设置进行测量。心血管功能和血液将通过靠近红外光谱（NIRS）标签的可穿戴，无创的连续波测量。此外，潜水径前后进行静脉抽血将提供轻度创伤性脑损伤，氧化应激和炎症的血液生物标志物，并与NIRS数据结合使用，以研究器官和组织稳态的变化。潜水和消耗猎物所需的能量消耗将使用潜水和恢复间隔持续时间以及根据开放流呼吸测定法计算得出的总氧气和二氧化碳产生。这些指标将共同允许测试和校准能量支出的指标，这些指标可以将其纳入NIRS标签的船上数据处理中，以进行未来的现场部署。最后，将将生理和能量的结果纳入现有的PCOD模型，以预测扰动的个体和人口水平的后果。