This report presents a first attempt to map human activities, pressures and potential cumulative impacts in the eastern parts of the North Sea. The mapping is based on existing data on human activities in Denmark, Germany, Norway and Sweden. In addition, ecosystem components, e.g. broad-scale benthic habitats, fish, birds and marine mammal have been mapped. In order to link human activities and ecosystem components, an online survey was carried out involving experts from the involved countries. The highest estimated potential impacts were found in the German Bight, the Sound and in the coastal water of the Kattegat, whilst the lowest impacts were estimated for the western and northern parts of the study area. The results can be used for the initial assessment in the context of the EU Marine Strategy Framework Directive (MSFD). The HARMONY project has also developed and made available a toolbox supporting national MSFD implementation with special focus on issues of a transnational relevance and importance. It builds on cooperation among member states sharing the Greater North Sea sub-region through active involvement in several OSPAR groups.
Questions this practice may help answer:
- Which human activity causes which pressures, affecting which ecosystem components?
- How far do the effects of the pressure reach from its source?
- How vulnerable are the ecosystem components to different pressures, at the levels caused by the respective human activities?
The presented methodology and first results are part of the HARMONY project, which aims in developing and demonstrating tools for harmonization of the MSFD initial assessment in the eastern parts of the North Sea. The project tackles two main challenges:
- to gather and harmonize ecological information;
- to collect data on the spatial distribution and intensity of human activities in the respective sea areas.
Aspects / Objectives
- Elaboration of a methodological framework for mapping cumulative human impacts, adjusted to the requirements of the Marine Strategy Framework Directive.
- Summary of results from an online expert survey, to study the linking of human uses, the resulting pressures and their impacts on key ecosystem components.
- Presentation of three different indices, the North Sea Human Use Index, The North Sea Pressure Index and the North Sea Impact Index.
The general framework for mapping cumulative human impacts on marine ecosystems by Halpern et al has been further developed and adjusted to the requirements of the Marine Strategy Framework Directive (MSDF). First, an explicit distinction has been made between human uses of the sea and the pressures they cause. This distinction is based on Annex III, Table 2 of the MSFD. In addition, different pressures caused by the same human use have been analysed separately, as they show different patterns of distribution and affect different components of the ecosystem.
Second, formally defined spatial models, were recommended by experts. These models are defined by distance or estimated area and its ecosystem impacted by potential human pressures against a described sensitivity score. They have been used for all activity-pressure combinations to describe the spatial extent of the pressures.
Third, predictive distribution models of key species listed, in Annex III, Table 1 of the MSDF, have been used. These models are transferrable, and can be redesigned to adapt to specific studies, depending on the area, type of pressure and ecosystem to be impacted. It also covers a broad range of uses and ecosystems and therefore can be applied both at local and more broader levels.
Fourth, instead of using simple presence-absence maps for ecosystem components, the distribution has been modelled as the probability of presence. This methodology is particularly relevant for mobile components such as fish, birds and mammals.
The mapping is based on different but harmonized sets of data, combined with information from an online survey among experts. The datasets as well as the maps were created with standard GIS software (ESRI ArcGIS 10). For the calculation of the indices however, a dedicated software was developed.
Main Outputs / Results
The results of the online survey of experts in an overview of which human activities cause which pressures, and over which distances the pressures diminish from their source according to the participating experts. Pressure distance are defined differently for broad-scale habitats, communities and ecosystems and differently for species. For broad-scale habitats, communities and ecosystems, pressures distances define how far from the location of the activity the pressure will diminish to a negligible level, given the sensitivity of the community, habitat and the coastal ecosystem as a whole. The same definition applies for species, dependent upon the sensitivity of the given species. The pressure distances were later used to select the most suitable spatial model for calculating the indices.
The maps based on the North Sea Human Use Index (NSUI) indicate areas of high and low intensity of human activities (including economic as well as other non-economic uses). The result depends on how strongly fishery is influencing the outcome. Including all nine fisheries data sets the outcome shows highest intensity of human activities in the coastal waters of the Kattegat, followed by areas in the German Bight.
The North Sea Pressure Index (NSPI) includes different pressures resulting from the human activities included in the study. Furthermore, it contains the distance up to which the pressures are noticeable. The maps based on the NSPI show, that the strongly affected areas get larger compared to the maps showing the NSUI. Especially the German coast of islands is highly affected, but also the Kattegat as well as the Sound.
The North Sea Impact Index (NSII) in addition to the NSPI includes the spatial distribution and sensitivity of the ecosystem components to different stressors. Areas with a high level of NSII are characterized by an overlap of many pressures and sensitive ecosystem components. A low level of NSII might be an indicator for low pressure, or an ecosystem that is not sensitive to the kind of pressures occurring. Compared to the maps resulting from NSUI and NSPI, the maps showing NSII indicate even larger areas of high impact, covering the whole German Bight, the southern Kattegat and the Sound. However, the distribution of affected areas changes significantly when only including one specific group of ecosystem components like benthic, fish, plankton, birds or mammals.
Instead of confronting decision-makers with one map of cumulative human impacts (which they may believe in or not), the presented methodological framework allows them to calculate own indices, for example to explore the effects of turning on and off particular human activities, pressures and ecosystem components.
Depending on data availability, this assessment can be transferred and used in MSP processes. Its practical meaning is justified by the need for EU member states, per the EU Maritime Strategy Framework Directive (MSFD; EC 2008) to adopt measures to achieve or maintain good environmental status (GES) in the marine environment by 2020. For this purpose, member states must ensure their marine strategies aim to protect and preserve the ecosystem, and where is has deteriorated, restore it to a healthy state. The ability to devise measures and strategies lies greatly in the understanding of the existing marine social and ecological systems functioning and provisioning and the pressures and potential impacts they will have on the marine environment. Spatial analysis of anthropogenic stressors and their cumulative impacts in the marine environment is therefore necessary for implementing the ecosystem-based approach to Maritime Spatial Planning.
The following projects are all anchored in the HARMONY project: The Swedish SYMPHONY project and its DSS, HELCOM HOLAS 2, and the Danish ECOMAR project. The later will develop a state-of-the-art MSP tool box including: 1) a data hangar, 2) cumulative impacts assessment, 3) uncertainty assessment, 4) a tool for zoning based on a combination of CIA, Marxan and SeaSketch as well as 5) a flexible and user-friendly application for a broad range of MSP analyses and scenario calculations.
Aarhus University – Danish Centre for Environment and Energy
Tel: +45 8715 5000
Jesper H. Andersen
 Halpern, B.S., Selkoe, K.A., Micheli, F. & Kappel, C.V. 2007: Evaluating and Ranking the Vulnerability of Global Marine Ecosystems to Anthropogenic Threats. - Conservation Biology 21(5): 1301-1315.
 Halpern, B.S., Walbridge, S., Selkoe, K.A., Kappel, C.V., Micheli, F., D’Agrosa, C., Bruno, J.F., Casey, K.S., Ebert, C., Fox, H.E., Fujita, R., Heinemann, D., Lenihan, H.S., Madin, E.M.P., Perry, M.T., Selig, E.R., Spalding, M., Steneck, R. & Watson, R. 2008: A Global Map of Human Impact on Marine Ecosystems. - Science 319(5865): 948-952.