Integrated Risk Assessment Framework for Evaluating the Combined Impacts of Multiple Pressures on Arctic Ecosystems

Arctic ecosystems are subject to multiple pressures, including climate change and exposure to long-range transported, persistent, bioaccumulative, and toxic contaminants, and there is a need to enhance the understanding of combined impacts of multiple pressures and their interactions on Arctic ecosystem state and health. This calls for better integration of research within and across disciplines in a comprehensive research initiative. The primary objective of this project is to develop, explore, and evaluate a novel integrated risk assessment framework for assessing combined impacts of multiple pressures on the state of Arctic ecosystems. The main focus is on interacting effects of persistent organic pollutants (POPs) and climate change on four top-predators of a coastal ecosystem (black-legged kittiwakes, glaucous gulls and common eiders in Kongsfjorden, Svalbard) and an offshore Arctic marine ecosystem (polar bears in the Barents Sea). A key activity in the project has been to develop the framework, including development of modelling tools. One of the key models is the Nested Exposure Model (NEM). The model consists of a global temporally and spatially resolved module for contaminant fate in the physical environment, and a bioaccumulation module for organic contaminants in food webs typical for the Norwegian Arctic areas. The overall aim is to simulate the whole link between global emissions of organic contaminants and Arctic ecosystem exposure in the context of climate change, also including variation in space and time. A scientific paper describing the bioaccumulation module in NEM, evaluating it for PCB-153 in Norwegian fish and in the Kongsfjorden ecosystem, and applying it to identify the sources of PCB-153 to Norwegian marine areas was published in 2023. The model is currently being further developed to evaluate how climate change scenarios influence contaminant dynamics in the three seabird species and the polar bear. Field work was carried out in 2020-2023 in the Svalbard area, and all chemical analyses have been completed for time-series of POPs in the four top-predators. In addition, a polar bear prey library (composing 12 species) has been constructed which includes POP concentrations, triple stable isotopes, fatty acids and caloric content. The time-series are now used to investigate the impact of climate variability on observed temporal trends of POP concentrations in the species. The results for common eider were published in 2023, and showed positive correlations between mean effective temperature during breeding and concentrations of most of the investigated POPs in the eiders, implying indirect climate effects leading to higher POP concentrations. For the black-legged kittiwake and glaucous gull innovative time series analysis is currently in process, and publication of a manuscript for each species is expected during 2024. The time-series for the four top-predators are also being used to evaluate the performance of NEM. Complementary Bayesian Network Analysis (BNA) modeling on polar bears is also in progress, using input from the above-mentioned prey library, and is currently being developed to be semi-spatially explicit. Significant advances have been made in COPE on defining a novel conceptual framework. The framework links spatiotemporal-explicit climate, ecological and contaminant libraries into a network of statistical and mechanistic modeling approaches (including NEM and BNA). The polar bear data is currently being used to demonstrate the framework. Moreover, participation in an invited Technical Workshop of the Society of Environmental Chemistry and Toxicology has resulted in a publication on “Advancing exposure assessment approaches to improve wildlife risk assessment”. To enable scientifically-sound regulation of POPs in remote regions, it is also vital to understand their sources. Therefore, COPE has contributed to several published scientific papers on global release of POPs and spatial distribution of POPs in the European and Canadian atmosphere, including for Dechlorane Plus which was added to the Stockholm Convention in 2023. To ensure good communication with relevant environmental authorities, dialogue with the Norwegian Environment Agency was established early in the project, and they have participated in COPEs annual meetings. In addition, results from COPE have been presented at national and international conferences. An Arctic Frontiers side-event was arranged in May 2022 with the topic “Turning science into policy for a sustainable Arctic – How to cope with an Arctic ecosystem under multiple pressures.” In addition, a scientific session on “Adaptive management of rapidly changing Arctic ecosystems using interdisciplinary and system-science approaches” was held in January 2023 at Arctic Frontiers, further strengthening the interface between scientists, stakeholders and policy makers.

Arctic ecosystems are subject to multiple pressures, of which two of the major challenges are climate change and exposure to long-range transported, persistent, bioaccumulative, and toxic contaminants. These issues have largely been addressed individually, yet there is a critical need to enhance the understanding of combined impacts of multiple pressures and their interactions on Arctic ecosystem state and health. This calls for better integration of research both within and across disciplines in a comprehensive research initiative. The primary objective of this proposal is to develop, explore, and evaluate a novel integrated risk assessment framework for assessing combined impacts of multiple pressures on the state of Arctic ecosystems. The focus herein will be upon data-rich pressures and ecosystems to enable development and a thorough evaluation of the framework. Hence, the initial focus will be on interacting effects of environmental organic contaminants and climate change on top-predators of a coastal and an offshore Arctic marine ecosystem in the Svalbard and Barents Sea areas. Important sub-goals include research to (1) develop the framework through evaluating existing knowledge of the most relevant pressures and their interactions, (2) explore the utility of the framework to assess interactions of contaminants and climate change on the state of two selected Arctic marine ecosystems, (3) explore the utility of the framework to assess combined impacts across ecosystems, space, and time, and (4) evaluate the overall framework, guide further research, and communicate key results to regulatory bodies and institutions. Overall, the project is designed to both (i) strengthen research on critical Arctic environmental issues across disciplines and institutions, and (ii) contribute with scientific knowledge and possible mitigation strategies of interest to relevant environmental agencies as well as international programs and agreements.