Effects of changes in discharges, climate and other factors on coastal contaminants and their biological consequences (COCO)

The fate of environmental contaminants, from pollution source via different environmental influences to accumulation and possible effects in organisms is complex: strong reductions in discharges of a contaminant are not always followed by reduced concentrations in the environment or in organisms. Furthermore, the fate of the contaminants may also be affected by other factors, e.g. driven by climate change. In addition, biological effects of the exposure of organisms to contaminants may be altered in tune with other aspects of the organism's environment. In the "COCO" project the main objective has been to increase the knowledge of how changes in discharges/exposure, modulated by climate and other environmental factors, affect the pollution levels in Norwegian waters, and to increase the understanding of biological consequences of such changes. For this we have used historic data/databases to study different processes and relationships over several years. The main data source for this project has been environmental monitoring data on contaminants in fish, mussels and other organisms, as well as sediments, from Norwegian waters. In addition, we have used climate data, such as data on wind and temperature, which are factors which (through different mechanisms) can both change the amount of contaminants that are available to the organisms and the robustness of the fish population. We have organized a large amount of data and published several works. After the end of the project we will publish even more articles that are currently in preparation. Our results include: -Apparent increases in concentrations of mercury in cod are largely due to increasing fish size. -Capping of sediments in parts of a contaminated fjord system will cause the contaminant level in biota to reach a moderate level a decade earlier than otherwise. -Concentrations of metals in sediments along the Norwegian coast are mainly driven by historical industrial pollution at certain sites, while PAH and PCB compounds show more diffuse pollution, with a south-north gradient in the PAH concentrations. -Recruitment of cod correlates with both climate (wind and temperature) and concentrations of certain pollutants. The COCO project has provided the participating institutions with an important foundation for future research collaboration. Through the project, it also became clear that work with this type of data generates new questions and hypotheses as one penetrates deeper into the data. This is also evident through the number of works we have initiated during the project period, but that was not consolidated as well in advance of the project. This also provides good basis for future research initiatives. The COCO-project has essentially been completed according to plan in terms of progress, economy and deliverables. The project has shown value in terms of science, society and nature management. This is justified in that the project we have conducted research particularly relating to issues relating to pollution and climate change, and possible remediation of pollution. We mean to find support for this view in that there has been interest in the work as it has been presented in academic and popular forums. The project has disseminated the results through peer-reviewed articles, and presentations at national and international conferences. Some work has also received coverage in the mass media. Since the project has had a profile with expected utility value for nature management, experts and managers were invited and gathered for two workshops during the project period. These had the titles "Environmental contaminants in food webs" and "Measurement of biological effects as research- and management tools - Status and Perspectives."

The fate of contaminants, from pollution source via environmental modulation to accumulation and possible effects in organisms is complex: strong reductions in discharges of a contaminant are not always followed by reduced concentrations in the environmen t or in biota. The fate of contaminants may also be affected by other factors e.g. driven by climate change. In addition, biological effects of the exposure and organism's contaminant burden may be modulated in tune with other aspects of the organism's en vironment such as food availability, etc. In COCO historic monitoring data allow us to study processes and relationships on a decadal time scale. A large amount of time series data on contaminant concentrations in biota and abiotic matrices, biological ef fect parameters, abundance of fish populations, and biogeochemical parameters are available for several locations along the Norwegian coast, including "clean" reference locations. Two fjord systems with long known pollution history, however, will be in pa rticular focus: Sørfjord and the Grenlandfjords. Particular good time series exist for these fjords (monitoring data). In both fjords, there has been high release of contaminants, which subsequently has been strongly reduced. The expectation would be that organism body burdens of a contaminant would decrease following termination of the release of this particular contaminant, but this has not always been the case. In both locations, some contaminants have been stable or increased in organisms years after the release of these substances were terminated. For several important contaminants, we will perform a comprehensive, systematic analysis of the relationship between contaminant release, concentrations in the environment (sediments and water), the body bu rden in organisms, sublethal effect parameters/biomarker responses and (for cod) local abundance. We will then investigate the effects of climate and biogeochemical conditions on the strength of these relationships.