Uptake of chemicals from legacy waste sites in coastal food webs and effects on higher predators

Disused waste disposal sites (e.g. historic landfills, mining, coal gasification and fly ash spoil sites and 'night soil' disposal areas) may be important sources of legacy (e.g. metals, persistent organic compounds, biocides) and emerging (e.g. pharmaceuticals, personal care products, transformation products and micro and nano-polymers) pollutants into coastal environments. The occurrence of these pollutants in water and sediment compartments can result in the entry of a mixture of toxicants into aquatic food chains. Exposure to combinations of chemicals released from legacy waste sites could lead to demographic impacts on higher predators of high conservation concern, such as seabirds, that could affect population resilience. A spatial explicit exposure assessment framework that establishes the importance of disused waste sites as a source of exposure and risk for multiple pollutants through coastal food chains is therefore needed to support management decisions for legacy waste sites close to protected habitats and vulnerable wildlife populations.

In this project, we will develop and test a food web exposure and risk assessment modelling framework for legacy waste site-derived pollutants. We will combine historic analyses of waste disposal practices with environmental monitoring, advanced analytical chemistry and food chain and hazard assessments to establish the transfer of waste site derived chemical contaminants through coastal marine food chains and the impacts of these exposures for seabird populations. The potential for our approach to estimate exposure and effects will be assessed by directly monitoring the demography and physiological status of a higher predator bird species, the European shag. European shags are an excellent choice for these studies because their coastal feeding habits may lead to high exposure to contaminated moving from legacy sites on land into the sea. Further, their ability to excrete some types of organic contaminants is potentially limited, as indicated by past work that has shown this species to have to some of the highest loading of any seabird species for persistent organic pollutants.

We will develop, parameterise and test our exposure and risk models for colonies in the Firth of Forth, an area with a high density of legacy waste sites that is also a proposed Special Protection Area for seabirds. We will monitor individual shags at colonies with potentially high exposure (close proximity to multiple waste sites - Inchkeith to the West) and moderate exposure (fewer proximal sites - Isle of May to the East). Within colonies, we will study separate groups of birds displaying contrasting migratory habits. Some remain in the Firth of Forth all year round, while others head to the North Aberdeenshire coast outside of the breeding season (an area with few legacy waste sites, and hence potentially low exposure). By measuring the demography and physiology of individuals from different colonies and with different migratory patterns, we can compare how well our modelling framework predicts exposure and potential risk under different exposure scenarios. Throughout the project, we will work with key stakeholders from the policy, regulatory, industry and NGO sectors to explore how to use our models alongside existing regulatory regimes to mitigate any identified adverse impacts on coastal waste sites on wildlife populations. Our approach will be transferable to other coastal regions in the UK and beyond.

Our project will achieve two major dimensions of societal impact:

1) It will shape waste and conservation policy. We will maximize impact of the project by working closely with key stakeholders (waste management and regulation and policy organisations; conservation agencies and NGOs) throughout the project in a co-design approach to ensure that the final outputs from the project are usable. We will work with the waste policy and management sector activities who are responsible for regulating historical and extant contamination (e.g. under Part IIA of the Environmental Protection Act and the Environmental Liability Directive) and with representatives from the waste management industry to 1) identify the practical constraints and barriers which arise when addressing the consequences of legacy waste sites, specifically in the context of the highly urbanized coastal zone; 2) define the structure, design and outputs of our final framework; 3) stress-test the emerging framework in different regulatory scenarios in liaison with regulators and industry stakeholders; develop an end user toolkit to translate our framework into real world application. We will set a joint agenda with conservation policy makers and NGOs for priority policy issues around wildlife conservation to be addressed during the project and the desired project outputs. These organisations will benefit from new data and understanding that they urgently require to support conservation policy on protected wildlife populations. In the coastal marine environment, seabirds are a particular focus because of their strong legal protection and marked declines over the last three decades. However, a lack of understanding of the demographic consequences of contaminants on seabirds is hampering conservation efforts. Our project will provide key evidence that conservation agencies and charities can use in their decision making regarding mitigation of contaminants.

2) It will facilitate public engagement in cutting-edge science. Public awareness of marine pollution has exploded in recent months. For example, microplastic pollution is now regarded by the public as a major issue (e.g. following the "Blue Planet" series in autumn 2017). However there is less awareness of the many other pollutant classes that will be emitted into the environment. In this project, we will address both issues. This will give us the opportunity to increase public awareness of presence of pollutants in the marine environment, and the potential risk (if any) that mixtures of these chemicals may pose. There is, therefore, an important communication process required to increase awareness of marine pollution more widely. We will achieve this goal through commonly used social media such as dedicated web sites, twitter and media stories.

The 'Pathways to Impact' document details the activities we will undertake to deliver this impact.