Linking Predator-Prey Dynamics: Spatiotemporal Trends in Marine Predation Around Shetland

连接捕食者与被捕食者的动态：设得兰群岛周围海洋捕食的时空趋势

• 批准号: 2906260
• 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-2906260
• 关键词: Linking; Predator; Prey; Dynamics; Spatiotemporal

Understanding the drivers of population dynamics is a fundamental question in both pure and applied ecology. For marine top predators quantifying the role that prey availability plays is critical in evaluating the potential impacts of current and planned human activities, and thus for environmentally sustainable management of the ecosystem. However, such research has been limited by a lack of prey data at an appropriate resolution, resulting in researchers primarily having to rely on coarse resolution prey data (International Council for the Exploration of the Sea; datras.ices.dk) or environmental covariates as proxies for prey availability. Such a lack of data has also hampered effective management of inshore fish stocks. Shetland benefits from a set of datasets (all available for this project), unique in the UK, that would allow exploration of the spatiotemporal relationship within and between top predators and fish. Moreover, Shetland is an area of conservation and management interest; it hosts significant fish diversity and populations of predator species while supporting high and increasing levels of marine resource acquisition. Shetland has a dedicated inshore fish survey (annual from 2011; SUHI). In addition, there are historic sandeel data (1974-1999). For seabirds, there are breeding abundance data, and a monthly beached bird survey measuring seabird corpse and oil pollution rates, from around Shetland for over four decades (SOTEAG, Seabird Monitoring Program & RSPB), resulting in one of the UK's most comprehensive datasets on seabird abundance. These data are augmented by extensive tracking datasets (seven species; RSPB). Furthermore, SMRU hold data on seal haulout abundance, diet and tracking data. These data show stark species and regional variation across Shetland in trends in abundance of fish, seabirds and seals. For example, the Shetland harbour seal population fell by ~ 40% between 2001 and 2015 with stable abundance prior to and following that fall. However, the areas encompassing the two (harbour seal) SACs show contrasting trend; the Yell Sound trend mirrors the Shetland-wide trend but southeast Shetland (includes Mousa SAC), has shown a continuing decline since the early 1990s. There is a lack of studies of long-term population trends across multiple species and trophic levels. Comparative analyses of trends of top predators can elucidate the drivers of change. Indeed, populations of species with a limited foraging plasticity are more sensitive to reduced prey availability.

理解种群动力学的驱动因素是纯生态学和应用生态学的一个基本问题。对于海洋顶级捕食者来说，量化猎物可获得性在评估当前和计划中的人类活动的潜在影响方面发挥的作用至关重要，因此对于生态系统的环境可持续管理至关重要。然而，由于缺乏适当分辨率的猎物数据，这种研究受到限制，导致研究人员主要不得不依赖粗分辨率猎物数据（国际海洋勘探理事会; datras.ices.dk）或环境协变量作为猎物可用性的代理。这种数据的缺乏也妨碍了对近海鱼类种群的有效管理。设得兰群岛受益于一组数据集（所有可用于本项目），在英国独特的，这将允许探索的时空关系内和之间的顶级捕食者和鱼类。此外，设得兰群岛是一个具有养护和管理意义的地区;该地区拥有丰富的鱼类多样性和捕食物种种群，同时支持大量和不断增加的海洋资源获取。设得兰群岛有专门的近海鱼类调查（自2011年起每年一次; SUHI）。此外，还有历史上的sandeel数据（1974-1999）。对于海鸟，有繁殖丰度数据，以及每月一次的海滩鸟类调查，测量海鸟尸体和石油污染率，来自设得兰群岛周围超过四十年（SOTEAG，海鸟监测计划和RSPB），产生了英国最全面的海鸟丰度数据集之一。这些数据通过广泛的跟踪数据集（七个物种; RSPB）得到增强。此外，SMRU还拥有海豹捕捞丰度、饮食和跟踪数据。这些数据表明，整个设得兰群岛的鱼类、海鸟和海豹数量趋势存在明显的物种和区域差异。例如，设得兰群岛的海豹数量在2001年至2015年期间下降了约40%，在下降之前和之后数量稳定。然而，包括两个（斑海豹）SAC的地区显示出相反的趋势;耶尔湾的趋势反映了设得兰群岛范围内的趋势，但设得兰群岛东南部（包括穆萨SAC）自20世纪90年代初以来一直在持续下降。缺乏对多个物种和营养级的长期种群趋势的研究。对顶级捕食者趋势的比较分析可以阐明变化的驱动因素。事实上，觅食可塑性有限的物种种群对猎物减少更敏感。