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.

了解种群动态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，量化猎物可用性所发挥的作用对于评估当前和计划中的人类活动的潜在影响至关重要，从而对生态系统进行环境可持续管理。然而，此类研究因缺乏适当分辨率的猎物数据而受到限制，导致研究人员主要不得不依赖粗分辨率的猎物数据（国际海洋探索理事会；datras.ices.dk）或环境协变量，例如猎物可用性的代理。数据的缺乏也阻碍了近海鱼类种群的有效管理。设得兰群岛受益于一组在英国独一无二的数据集（全部可用于该项目），这将允许探索顶级捕食者和鱼类内部和之间的时空关系。此外，设得兰群岛是一个具有保护和管理意义的地区；它拥有丰富的鱼类多样性和捕食物种种群，同时支持高水平且不断增加的海洋资源获取。设得兰群岛有专门的近岸鱼类调查（从 2011 年开始每年一次；SUHI）。此外，还有历史的鳀鱼数据（1974-1999）。对于海鸟，有四十多年来设得兰群岛周围的繁殖丰度数据以及每月一次的搁浅鸟类调查，测量海鸟尸体和石油污染率（SOTEAG、海鸟监测计划和皇家鸟类保护协会），从而形成了英国最全面的数据集之一海鸟丰富。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 还保存有关海豹捕捞数量、饮食和跟踪数据的数据。这些数据显示了设得兰群岛鱼类、海鸟和海豹数量趋势的明显物种和区域差异。例如，2001 年至 2015 年间，设得兰斑海豹的数量下降了约 40%，但在下降之前和之后数量保持稳定。然而，两个（斑海豹）SAC 周围的区域却呈现出截然不同的趋势； Yell Sound 趋势反映了整个设得兰群岛的趋势，但设得兰群岛东南部（包括 Mousa SAC）自 20 世纪 90 年代初以来一直呈现持续下降趋势。缺乏对多个物种和营养级别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可用性的减少更为敏感。