Light pollution in European protected areas: Spatial variation of light pollution in Natura 2000 sites of the Member States of the European Union
Hügli, F., 2021: Light pollution in European protected areas: Spatial variation of light pollution in Natura 2000 sites of the Member States of the European Union. Master thesis. 47 p.
Hügli, F., 2021: Light pollution in European protected areas: Spatial variation of light pollution in Natura 2000 sites of the Member States of the European Union. Master Thesis ETHZ, D-USYS. Supervisors: PD Dr. J. Bolliger, Prof. Dr. F. Kienast
Natura 2000 sites are designated by the European Union under the Nature Directives, i.e. the 1979 Birds and 1992 Habitats Directives to counteract and mitigate biodiversity loss. Natura 2000 conservation sites are important areas to ensure the persistence of Europe’s most precious and threatened habitats and species. The sites cover a total of 17.9% of the European Union's surface and 9.7% of its marine area. Among current environmental challenges, light pollution has been identified as an increasing threat – also for protected sites. In this thesis, light pollution was examined spatially explicitly across Europe for terrestrial and marine Natura 2000 sites using satellite data (VIIRS-DNB) from 2018 and 2019. Based on three published and two additional thresholds, the magnitude of light emissions (measured in nW) was categorised. Light emission values >=2 nW are recognized to have at least low level of ecological impact. Considering all terrestrial Natura 2000 sites across the EU, 96.13% of the areas were exposed to low (<2 nW) and 3.87% to light levels >=2 nW (0.17% to high light levels; >=20 nW). While this may at first not appear to be a cause for concern, further analyses of the Natura 2000 sites for individual biogeographical regions and EU Member States in which they are situated, revealed significant differences in light exposure. Whereas more than 90% of Natura 2000 areas in the Alpine and Boreal regions were in the lowest (<0.5 nW) light pollution class, in the Macaronesia region it was only 69.55%. Out of all seven biogeographical regions, the Macaronesia region also had the most Natura 2000 areas (0.77%) with high (>=20 nW) light pollution. Natura 2000 sites in Luxembourg (16.9%), Belgium (19.7%) and especially Malta (63.95%) were exposed by far to the highest amount of light greater than or equal to 2 nW. In comparison, only 1.09% of Natura 2000 sites in Estonia had a value >=2 nW and an astonishing 96.39% were in the lowest (<0.5 nW) light pollution class. Areas within Luxembourg, Belgium and Malta with the highest levels of light pollution have been identified and mapped. Built-up areas such as (nearby) airports, ports, industrial areas or greenhouses were found to be the source of high light exposure. The finding that a proportion of artificial areas are largely responsible for high light pollution was further supported by an analysis of land cover classes of Natura 2000 sites, e.g. sites containing wetlands were found to be the least exposed to light pollution. Marine Natura 2000 sites were studied within three buffer areas from the coast. Within 1000m, comparable light exposure was measured as for terrestrial Natura 2000 areas of the Macaronesia biogeographical region. However, starting at 1000m distance from the coast, the area within the lowest (<0.5 nW) light pollution class increased by 13.89% from 64.44% to 78.33%. The proportion of lowest light exposure continued to grow by 6.06% within a buffer between 2000-3000m from the coast. Between 2000-3000m were no more Natura 2000 sites with high light pollution. With only a few exceptions light exposure levels were higher in 2019 than in 2018 for both, terrestrial and marine Natura 2000 sites. Considering light pollution levels >=2 nW, the largest decrease was recorded in Natura 2000 sites of Luxembourg (-2.1%) and the highest increase in Belgium (+2.3%). Given my results, I conclude that light pollution is an important driver of environmental change for the 21st century. Mitigation measures based on state-of-the-art light technological development should therefore be implemented at various political levels in order to delineate sustainable lighting strategies.