Environmental stress processes: the role of anthropogenic pollution in a rapidly changing terrestrial environment

Many hazardous pollutants have declined in the environment over the last decades, and it is thus timely to ask whether they still causes significant stress to wildlife and humans. Environmental stress consists of complex interactions between co-occurring natural and anthropogenic factors, so-called multiple stressors. The role of pollution as a stressor is thus not only determined by exposure, but is defined in combination with other stressors, such as feeding conditions and climate. The main aim of this project has been to document how pollution may modulate stress by studying key avian top predatory species in central Norway using long-term data on pollutant exposure, climate and feeding conditions. This interdisciplinary project studies terrestrial tawny owls and the freshwater goldeneye duck. Focus has been be on analyzing spatiotemporal variation in the concentrations of organohalogenated compounds (OHCs) and heavy metals, measured in eggs and feathers in relation to ecological and environmental factors. Furthermore, we aim at unravelling how pollutants modulate physiological stress responses by analyzing stress hormones in tawny owl feathers, collected over more than 3 decades. In addition, reproductive and survival data will be analyzed to test how pollution might interact with other environmental stressors to cause ecological effects. Access to unique long-term data series from adjacent habitats will enable us to assess the potential of pollution to modulate stress pathways, and thus capacity of these top predators to adapt to a rapidly changing environment. The results demonstrate how the distribution of heavy metals are influenced by landscape formations, industry and settlements, and how OHCs accumulates differently in adjacent terrestrial and freshwater ecosystems. Both profiles, trends and annual variation differ, which strongly indicates that biological and physical processes influences the contaminants differently, also locally.

This interdisciplinary and international project has increased research collaboration and provided results about the distribution of pollution in different ecosystems that is very usleful for different stakeholders such as management.

The concentrations of many environmentally hazardous pollutants have dropped over the last decades. It is thus timely to ask whether they still pose significant stress to wildlife and humans. Environmental stress consists of complex interactions between co-occurring natural and anthropogenic factors ? so-called multiple stressors. The role of pollution as a stressor is thus not only determined by exposure, but is defined in combination with other stressors, such as feeding conditions and climate. The main aim of this project is to document how pollution may modulate stress by studying key avian top predatory species in central Norway using long-term data on pollutant exposure, climate and feeding conditions. This interdisciplinary project will apply theories and methods from ecology, climatology, and landscape ecotoxicology to study terrestrial tawny owls (Strix aluco), and the freshwater goldeneye duck (Bucephala clangula). We will have more than 30 years of detailed (individual-level) data from tawny owls and 20 years for goldeneye. Work package 1 will analyse spatiotemporal variation in the concentrations of organohalogenated compounds and elements, measured in eggs and feathers in relation to ecological (food availability, diet composition, breeding density and morphology) and environmental factors (climate and anthropogenic activity). Work package 2 will unravel how pollutants modulate physiological stress responses by analysing stress hormones in tawny owl feathers, collected over more than 3 decades based on the spatiotemporal gradients identified in WP1. In addition, reproductive and survival data will be analysed to test how pollution might interact with other environmental stressors to cause ecological effects. Access to unique long-term data series from adjacent habitats will enable us to assess the potential of pollution to modulate stress pathways, and thus capacity of these top predators to adapt to a rapidly changing environment.