Are we stealing food from the birds? Developing the evidence base to develop targets for ecologically sustainable fisheries

海鸟在海洋食物网中扮演着至关重要的角色，但在全球范围内，近几十年来它们的数量明显下降，28%的物种现在面临灭绝的威胁。它们在海上面临许多威胁，包括商业渔业（通过竞争和副渔获）、气候变化和污染。它们在陆地上也面临着严峻的挑战，包括外来入侵掠食者、栖息地退化和人类干扰，人们对近海可再生能源开发的有害影响相当关注。海鸟对这些威胁的敏感性，它们在英国等沿海国家的重要文化和经济意义，以及记录其种群趋势的优秀监测数据，导致海鸟的丰度和繁殖成功被作为OSPAR海洋生物多样性状况的共同指标。然而，为了充分了解海鸟、其他海洋捕食者、被捕食物种和人类活动之间的相互作用，有必要在这个生态系统尺度上量化时空动态。我们知道，许多海鸟以远洋鱼类为食，跟踪和建模研究为我们提供了英国周围海域海鸟捕食压力的空间分布的良好知识。但是，将这种方法扩展到更广泛的食物网，由于在这些觅食范围内绘制猎物种类分布的困难而受到限制。该项目结合了海鸟生态学、渔业监测和生态数据科学来克服这一障碍，将渔业声学的最新数据与拖网调查以及商业渔船的渔获量和努力量数据相结合，并将其与海鸟捕食压力和海鸟饮食的空间分辨估计相结合，以确定觅食区、渔业和海洋保护区之间的重叠。这些关键信息将纳入政府的25年环境计划，帮助优先采取行动，将生态系统方法纳入可持续渔业管理，同时保护海鸟种群。该项目的总体目标是更好地了解海鸟、它们的猎物、其他竞争捕食者和商业渔业之间复杂的相互作用，以便为管理工作提供信息，以推动可持续渔业，同时保持健康的海鸟种群。为了实现这一目标，学生将：模拟凯尔特和北海渔业的鱼食性鱼类和猎物的空间分布，应用海鸟的多物种功能响应模型来确定它们的猎物需求，研究猎物可用性的时间变化。以及食鱼鱼类和海鸟的消费需求和海鸟种群的死亡率/产量，确定该地区的渔业捕捞是否对海鸟的繁殖成功产生有害影响，以及/或食鱼鱼类和海鸟之间的竞争是否会加剧这种影响。该项目利用宏观生态数据科学方法将海鸟生态学与渔业科学和监测相结合，并将首次将海鸟捕食模型与对猎物分布、竞争捕食者和渔业的详细时空理解结合起来。它将为政府的25年环境计划提供及时的支持，并为英国海洋战略做出贡献，其中海鸟的减少被证明和建议与猎物的减少有关，从而填补了证据空白，从而能够制定基于生态系统的管理措施。它还将解决渔业生态兼容性的紧迫问题，在英国准备离开共同渔业政策之际，这对实施英国渔业法案的“可持续性目标”和“生态系统目标”至关重要。

BackgroundSeabirds play a crucial role in marine food webs, but globally they have shown marked population declines in recent decades with 28% of species now threatened with extinction. They face a number of threats at sea including commercial fisheries (through competition and bycatch), climate change and pollution. They also face serious challenges on land, including alien invasive predators, habitat degradation and human disturbance, and there is considerable concern about the detrimental impacts off offshore renewable developments. The sensitivity of seabirds to these threats, their significant cultural and economic importance in coastal countries like the UK, and excellent monitoring data documenting their population trends, have led to seabird abundance and breeding success being adopted as OSPAR common indicators of the state of marine biodiversity. However, in order to fully understand the interactions between seabirds, other marine predators, prey species, and human activities, it is essential to quantify spatio-temporal dynamics at this ecosystem scale. We know that many seabird species forage heavily on pelagic fish, and tracking and modelling studies have provided us with a good knowledge of the spatial distribution of predation pressure from seabirds in the seas surrounding the UK. But extending this to the wider food web is limited by the difficulty in mapping the distribution of prey species within these foraging ranges. This project combines seabird ecology, fisheries monitoring, and ecological data science to overcome this barrier, integrating newly-available data from fisheries acoustics with trawl surveys along with catch and effort data from commercial fishing vessels, and combining this with spatially-resolved estimates of seabird predation pressure and seabird diet, to identify overlap between foraging zones, fisheries and marine protected areas. This crucial information will feed in to the Government's 25 Year Environment Plan, helping to prioritise actions that will embed the ecosystem approach into sustainable fisheries management whilst conserving seabird populations.ObjectivesThe overall objective of this project is to better understand the complex interactions between seabirds, their prey, other competing predators, and commercial fisheries, in order to inform management efforts to drive sustainable fisheries whilst maintaining healthy seabird populations. To achieve this, the student will:Model the spatial distribution of piscivorous fish and prey alongside fisheries in the Celtic and North SeasApply a multi-species functional response model for seabirds to identify their prey requirementsInvestigate temporal change in prey availability, alongside consumption requirements of piscivorous fish and seabirds and mortality/production at seabird coloniesIdentify whether fisheries catch in the area is creating a detrimental impact on seabird breeding success and/or if competition between piscivorous fish and seabirds might exacerbate this impact.Novelty and TimelinessThis project is novel in using macroecological data science methods to integrate seabird ecology with fisheries science and monitoring, and will for the first time unite models of seabird predation with a detailed spatio-temporal understanding of the distribution of prey, competing predators, and fisheries. It will provide timely support for the Government's 25 Year Environment Plan, and contribute to the UK Marine Strategy in which seabird declines were demonstrated and suggested to be linked to declines in prey, thus filling an evidence gap that will enable the development of ecosystem-based management measures. It will also address the pressing issue of the ecological compatibility of fisheries, essential to implement both the "sustainability objective" and "ecosystem objective" of the UK Fisheries Bill as Britain prepares to leave the Common Fisheries Policy.