Collaborative Research: At-sea experimental disturbances to characterize physiological plasticity in diving northern elephant seals

海洋动物必须与持续的环境变化和海洋中日益增多的人类活动作斗争。干扰可以影响海洋哺乳动物的行为，但相关的生理成本尚不清楚。因为它们令人印象深刻的潜水能力是基于专门的生理学，所以很可能生理成本限制和定义了海洋哺乳动物对干扰的敏感性。该项目将通过使用实验性的海上干扰来调查北部象海豹潜水生理的变异性，这些干扰会引起对噪音的反应--噪音是全球关注的压力源。这些方法建立在最先进的记录技术基础上，并将开发一种新的探测器，能够检测体内的氧气管理。在常规潜水过程中，将对海豹的心血管生理和氧气利用进行测量，并与在海上经历远程实验干扰的动物进行比较。该项目的目标是了解该物种的生理范围和限制，并提供数据，预测海洋哺乳动物对自然和人为压力的恢复能力。这些数据将对敏感生态系统和其他不易研究的物种产生广泛影响。它将直接适用于海洋物种和栖息地的养护和管理。该项目将培训本科生、研究生和博士后研究员，并将包括通过州立公园和一个公共水族馆进行广泛的公共宣传。包括噪声污染在内的环境变化是对海洋生态系统结构和可持续功能的根本挑战。这个项目的目标是确定潜水海豹氧气管理中的生理变异性，它可以直接与个体在海洋中的成功联系在一起。该项目的三个目标将利用从移位的幼象海豹收集的海上数据，通过综合测量心血管生理学(EKG和血液或肌肉中的氧气传感器)，同时收集时间深度记录和三维加速度数据来解释水下活动，从而实现该项目的三个目标。目标1将通过描述心率、血氧耗竭、肌肉灌注和细微尺度潜水行为之间的相互关系，提供第一张全面的远洋潜水表型图。它还将评估具有不同水下氧气需求的肌肉灌流能力的分子标记物。目标2和3是基于在实验中诱导在许多水生物种中观察到的声音干扰的行为影响-延长潜水持续时间和增加运输成本。这两个目标都将检查氧气管理策略对刺激的反应。通过比较自然潜水和扰动潜水，可以评估潜水表型中的个体可塑性，包括行为和生理。这是关键的第一步，以确定模式物种延长潜水的能力，它们对海上自然潜水模式中断的反应，并最终预测它们无法补偿的干扰阈值。

Marine animals must contend with ongoing environmental shifts and increased human activities in the ocean. Disturbances can affect the behavior of marine mammals, yet associated physiological costs remain unknown. Because their impressive capacity for diving is based on specialized physiology, it is likely that physiological costs limit and define the sensitivity of marine mammals to disturbances. This project will investigate variability of dive physiology in northern elephant seals by using experimental at-sea disturbances that elicit responses to noise - a stressor of global concern. The methods build on state-of-the-art logging technologies and will develop a new probe that will be capable of detecting oxygen management in the body. Cardiovascular physiology and oxygen use of the seals will be measured during routine diving, and compared with animals that experience a remote experimental disturbance while at sea. The project goal is to understand the physiological range and limits of this species, and to provide data that could predict marine mammal resilience to natural and anthropogenic stressors. These data will have wide-reaching implications for sensitive ecosystems and other species of concern that are not easily studied. It will be directly applicable to conservation and management of marine species and habitats. The project will train undergraduates, graduate students and a postdoctoral researcher, and will include extensive public outreach via state parks, and a public aquarium. Environmental changes, including noise pollution, represent a fundamental challenge to the structure and sustainable function of marine ecosystems. The goal of this project is to identify physiological variability in the oxygen management of a diving seal that can be directly linked to individual success in the ocean. The project's three objectives will be achieved using at-sea data collected from translocated juvenile elephant seals, via integrated measurements of cardiovascular physiology (EKG and oxygen sensors in blood or muscle) with simultaneously collected time-depth records and 3-dimensional acceleration data to interpret underwater activity. Objective 1 will provide the first comprehensive picture of the dive phenotype in the open ocean by characterizing interrelationships among heart rate, blood oxygen depletion, muscle perfusion, and fine scale dive behavior. It will also assess molecular markers of perfusion capability in muscles with different underwater oxygen demands. Objectives 2 & 3 are based on experimentally inducing the behavioral effects of acoustic disturbance observed in many aquatic species - extended dive durations and increased cost of transport. Both objectives will examine oxygen management strategies in response to stimuli. Comparing natural versus perturbed dives permits an assessment of individual plasticity in the dive phenotype, incorporating behavior and physiology. This is a critical first step in determining the capacity of a model species to extend diving, their response to at-sea disruptions in natural dive patterns, and, ultimately, to predict thresholds of disturbance beyond which they cannot compensate.