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

点击翻译按钮获取中文摘要

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.