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No. 18: Human uses, pressures and impacts in the eastern North Sea

Andersen, J.H. & Stock, A. (eds.), Mannerla, M., Heinänen, S. & M. Vinther, M. 2013. Human uses, pressures and impacts in the eastern North Sea. Aarhus University, DCE – Danish Centre for Environment and Energy. 136 pp. Technical Report from DCE – Danish Centre for Environment and Energy No. 18. www.dmu.dk/Pub/TR18.pdf

Summary

We report the first ever attempt to map cumulative human pressures and impacts in the eastern parts of the North Sea. Our work is based on the following: (1) Spatial distribution of 33 human activities and types of land- and sea-based pollution, (2) spatial distribution of 28 “ecosystem components” (key species and habitats), (3) systematically collected expert judgment linking negative impacts on ecosystem components to human activities, and (4) the methodology published by Halpern et al. in 2008. We have expanded this methodology, for example allowing some environmental impacts related to e.g. underwater noise, chemical pollution and sediment spills to spread beyond the location of their source.

We present three indices describing the intensity of human uses, the magnitude of the resulting pressures, and the potential for cumulative human impacts (where many pressures overlap with sensitive ecosystem components). The results show significant spatial variations in cumulative human pressures and impacts within the study area, most related to spatial variation in human activities, but some related to variations in the distribution and vulnerability of specific ecosystem components.

This report makes two additional contributions. First, in order to develop the cumulative impact index for our study area, we conducted a detailed online survey about the sensitivity of key species and habitats to different human activities. We present lists of relevant human activities and pressures, the 53 survey respondents’ judgment about which human activities cause which pressures as listed in the Marine Strategy Framework Directive Annex III Table 2, and their ranking of these pressures in terms of threats to the North Sea. Second, in Appendices A and B to this report, we present an overview of the more than 60 regionally harmonized data sets describing the spatial distribution of human activities and pollution as well as ecosystem components, some of which have been exclusively prepared for this project.