iCod 2.0: Integrative environmental genomics of Atlantic cod (Gadus morhua); a holistic approach to characterize the biological effects of

Increasing numbers of structurally diverse chemicals are continuously being identified in biota as emerging contaminants, including in remote areas such as the Arctic and Polar regions. For most of these compounds, knowledge regarding their impacts on key species and ecosystems is limited, and even less is known about their potential mixture (also with legacy pollutants) and multiple stressor effects (e.g. ocean acidification). It is of great importance to address this lack of knowledge and provide new data that can shed light on the ecological risks and putative adverse effects of environmental pollutants on nature and wildlife. This knowledge is crucial for both national and international regulatory authorities in order to make informed decisions, guide policies, and for taking appropriate actions for conserving our environment. In the iCod 2.0 project we have used the commercially important Atlantic cod (Gadus morhua) as a model species, and studied responses to pollutants at different biological levels to obtain in-depth knowledge of the physiological effects of emerging contaminants and contaminant mixtures. We have focused on a set of emerging compounds that have recently been detected in coastal and Arctic species (such as perfluorinated compounds and bisphenols), a selection of legacy pollutants that are still predominant in biota (such as methylmercury, oil-related compounds, and PCB), as well as their putative pollutant interactions. For instance, we have recently studied how certain perfluorinated compounds (PFAS) can activate a master-regulator of the energy homeostasis in cod, and demonstrated how a mixture of these substances can further potentiate the activation of the receptor. This emphasizes how emerging contaminants can influence metabolic pathways and how mixtures of pollutants potentially can strengthen the adverse outcomes. During this project, we have revealed how several pollutants can act as enocrine- and metabolic disruptors, and potentially affect critical biological processes like growth, reproduction, and survival. We have obtained detailed knowledge of which cellular signaling pathways are affected by the exposure, how mixtures of chemicals can cause cross-talk between different signaling pathways, and how adaptive and compensating responses are activated in order to cope with the exposure. In addition, iCod 2.0 has provided knowledge that is important for extrapolating effects of environmental pollutants to other species, as well as data that aid the prediction of potential effects on populations and marine ecosystems.

iCod 2.0 has strengthened the collaboration between the project partner institutions, as well as promoted networking and new collaborations with other researchers and scientific institutions. iCod 2.0 has played a significant role in education of toxicologists at UIB, where numerous bachelor and master students have graduated with theses developed within this project. iCod 2.0 has been of high societal interest, and of great relevance for guiding both regional and national policies, and governmental regulations on environmental issues. Data generated in the iCod 2.0 project has been communicated to the Norwegian Environmental Agency and Miljøetaten at Bergen municipality, and will be further presented at relevant stakeholder meetings. Molecular tools developed in this project have applications as bioassays that can be used in environmental monitoring and risk assessment. We are currently exploring a future commercialization of this research together with Vestlandets Innovasjonselskap.

Increasing numbers of structurally diverse chemicals have been identified in biota as emerging contaminants, including in remote and sensitive areas such as the Arctic and Polar regions. Many of these compounds appear to have characteristics of persistent organic pollutants as they are resistant to physical, chemical and biochemical degradation, and therefore available for uptake and bioaccumulation for a long period of time. For the majority of these compounds, knowledge regarding their impacts on species and ecosystems is limited, and even less is known about their potential mixture (also with legacy pollutants) and multiple stressor effects (e.g. climate changes). Thus, it is a timely demand to address this lack of knowledge and provide new data that can shed light on the ecological risks and putative adverse effects of such environmental pollutants on nature and wildlife. To target this important challenge, we will in this project use the commercially important Atlantic cod (Gadus morhua) as a model species, and a holistic toxicogenomic approach to obtain in-depth knowledge of the physiological effects (including endocrine disruption) of a selected set of emerging contaminants and contaminant mixtures. We will focus on compounds that have recently been detected in coastal and Arctic species, as well as their putative interactions with abundant legacy pollutants. Importantly, this integrative holistic approach is not only expected to provide data of the individual characteristics of the different contaminants, their similarities and their interplay, but also provide an important framework that aid in elucidating phenotypic outcomes as a first step towards a thorough ecotoxicological understanding of contaminant exposures.