Collaborative Research: Determining the Field Metabolic Rate of Marine Predators: Integrating Accelerometry and Respirometry to Bridge the Gap Between the Laboratory and the Field

能量学是生态学的中心主题，新陈代谢可能是决定整个生物系统结构的主要因素。尽管顶级捕食者在海洋生态系统中很重要，需要了解它们的全球种群减少的影响，但令人惊讶的是，人们对上层营养层的能量流动知之甚少。这种认识上的差距是由于难以评估海洋捕食者的代谢率，以及无法将实验得出的代谢率与自由放养动物在其自然栖息地的代谢率联系起来。新的加速度计技术现在第一次使这种联系成为可能。由于整体动态身体加速度(ODBA)已被证明与许多脊椎动物的耗氧量密切相关，这一潜在的转化技术可用于计算自由活动的海洋捕食者的时间-能量平衡。智力优势：这项研究将结合使用呼吸测量和加速测量技术，弥合三种不同行为的鲨鱼在实验室和现场代谢率之间的差距。PIS将在实验室对配备加速计的动物进行呼吸测量实验，以确定在一系列游泳速度和水温下每个物种的代谢率和ODBA之间的关系。利用这些关系，PI将使用加速度计进行现场实验，以计算鲨鱼在自然栖息地几天内的绝对能量消耗。由于加速计还提供了可以量化特定鲨鱼行为的数据，PI将能够在标准代谢率和活跃代谢率之间进行划分，并确定关系在不同温度下如何变化。这一方面将对预测海洋表面温度的季节性或长期变化可能如何影响温控捕食者对猎物的影响产生影响。广泛影响：这项工作将提供数据和一种新的方法，用于根据自然行为模式估计鲨鱼在自然环境中的能量需求。这是计算鲨鱼对生态系统其他组成部分的营养影响的重要一步，从而也计算了鲨鱼数量减少的后果。这项工作将是莫特海洋实验室(MML)正在进行的NSF-REU项目的学生实习项目的基础，该项目为美国大学生提供研究经验，特别关注在科学和工程领域代表不足的少数群体。PI参与了一项独特的合作，即与未驯服的科学合作拍摄他们的工作，并用它来为特定章节的电影阐释科学概念，这将使他们的工作接触到全国数百万的K-12学生。该项目还将资助一种创造性的方式，通过在MML的公共水族馆(每年约有40万游客)举行的新展览，与普通公众建立联系。这利用了公众对鲨鱼的广泛兴趣，并允许游客使用基于加速度计的视频游戏控制器来控制数字鲨鱼。鲨鱼的能量水平将被过多的尾巴耗尽，并通过进食活动来补充，游客将不得不在进食成功的价值与更高的ODBA和快速能量消耗的成本之间进行权衡。

Energetics is a central theme in ecology, and metabolism may be the primary factor determining the structure of biological systems as a whole. Despite the importance of top level predators in marine ecosystems and the need to understand the impact of their global population declines, surprisingly little is known about energy flow in upper trophic levels. This gap in knowledge is due to the difficulty of assessing the metabolic rate of marine predators and the inability to link experimentally derived metabolic rates to those of free-ranging animals in their natural habitat. Novel accelerometry technology is now making this link possible for the first time. Because Overall Dynamic Body Acceleration (ODBA) has been shown to correlate closely with oxygen consumption in numerous vertebrate taxa, this potentially transformational technique can be used to derive time-energy budgets for free-ranging marine predators.Intellectual Merit: This study will integrate the use of respirometry and accelerometry technology to bridge the gap between laboratory- and field-based metabolic rates for three species of sharks with different behaviors. The PIs will conduct respirometry experiments on accelerometer-equipped animals in the laboratory to determine the relationship between metabolic rate and ODBA for each species over a range of swim speeds and water temperatures. Using these relationships, the PIs will then conduct field experiments using accelerometry to calculate the absolute energetic expenditure of sharks in their natural habitat over several days. Because accelerometers also provide data with which specific shark behaviors can be quantified, the PIs will be able to partition between standard and active metabolic rate and determine how the relationship changes at varying temperatures. This aspect will have implications for predicting how seasonal or long-term changes in sea surface temperatures are likely to affect the impact of ectothermic predators on their prey.Broader Impacts: This work will provide data and a new methodology for estimating energy demands of sharks in their natural environments following natural patterns of behavior. This is an important step in calculating the trophic effects of sharks on other components of ecosystems, and thereby also calculating the consequences of shark declines. This work will be the basis of student intern projects through the Mote Marine Laboratory's (MML's) ongoing NSF-REU Program, which provides research experiences to U.S. college students with a special focus on minority groups underrepresented in science and engineering. The PIs are involved in a unique collaboration with Untamed Science to film their work and use it to illustrate science concepts for chapter-specific films which will allow their work to reach millions of K-12 students nationwide. This project will also fund a creative way of connecting with the general public through a new exhibit at MML's public aquarium (with approximately 400,000 visitors per year). This capitalizes on the broad public interest in sharks and allows visitors to control a digital shark using an accelerometer-based videogame controller. Shark energy level will be depleted by excessive tailbeats and replenished by feeding events, and visitors will have to balance the value of feeding success against the cost of higher ODBA and rapid energy depletion.