Although there is acknowledgement that light pollution can be a ‘source of annoyance to people, it can be harmful to wildlife, waste energy and detract from the enjoyment of the night sky’ (CPRE 2016) there is only about a fifth of England that retains skies completely free of light pollution.
Light pollution is known to have an impact on species from insects to turtles. When it comes to bats, light pollution can impact on foraging site bat assemblages, commuting routes, can delay or prevent bats emerging from roosts, or can ‘in some cases lead to bats abandoning or becoming entombed in the roost’ (BCT).
In 1991 an Agreement on the Conservation of Populations of European Bats (EUROBATS) was established under article 4 of the Bonn Convention (CMS), with this agreement coming into force in 1994. In 1999 Jersey requested that the EUROBATS agreement be extended to the Bailiwick, this ratification only being possible once the Island had a law in place to protect bats. The ratification procedure was completed on 29th October 2001
EUROBATS is clear that light pollution negatively impacts bats and Jersey, as a signatory should be aiming to comply with the recommendations within this binding International Agreement. Specifically, EUROBATS resolution 8.6 recommends that parties undertake a number of actions to protect bats from light pollution, namely to:
- Take into account that artificial light in general has a negative impact on bats and should be avoided wherever and whenever possible.
- Work to ensure that planning of artificial lighting projects is undertaken in compliance with national legislation regarding bat protection and conservation by implementing appropriate avoidance, mitigation and compensation for habitat losses.
- Ensure that the impacts of artificial light on bats are included in impact assessment procedures.
- Work to resolve any conflict between artificial light and bats.
- Ensure that impact assessment procedures and post-installation/development monitoring are undertaken by appropriately experienced experts.
- Encourage developers of lighting concepts or responsible authorities to make raw data from impact assessments and post installation/development monitoring available for independent analysis.
- Encourage developers of lighting concepts or responsible authorities to make reports of impact assessments and post installation/development monitoring available for the public.
- Encourage and support scientific research on the impacts of artificial light on bats.
- Encourage all stakeholders to engage in research on the best methods for avoiding or mitigating the negative impacts of light pollution on bats.
- Promote continued cooperation between lighting professionals and other stakeholders in the search for best practice to avoid or minimise the adverse impact of artificial light on bats.
- Develop and promote implementation of national guidance taking due account of the EUROBATS Publication Series No. 8.
So where do we stand in Jersey and what can we do to help combat light pollution locally?
Light pollution is considered a nuisance under the Statutory Nuisances (Jersey) Law 1999 Article 2(d) where ‘light energy emitted from premises so as to be prejudicial to health or a nuisance’. This is only a when there is a nuisance to humans and not to wildlife.
There is a light pollution planning advice note on the Government website. It would be beneficial if this documentation could be updated in general and also expanded to include impacts on bats (in line with Eurobats resolution 8.6).
How can you help ?
- The control of light pollution should be a consideration of the Island Plan with a specific policy for the impact of light pollution on wildlife.
- Please, where possible raise the issue of light pollution with your States of Jersey representatives or via any further consultation processes under the Island Plan revision. You can note that Jersey has a requirement to have guidance concerning light pollution and bats
- If light pollution is a significant nuisance to you then please complain to Environmental Health
- If you live near to a recent development and have concerns about the light pollution and the impacts on wildlife then please contact Department of the Environment (Planning Department or Environment) or contact the Jersey Bat Group for further specific advice
- You can contact The Infrastructure Department and request that street lighting is dimmed at night or indeed turned off over night.
- The colour of the light is also important. ‘Warm white’ (more yellow/orange colour) at around 3000°K (Kelvin) and as low as 2700°K can now be used with little reduction in lumen output. LED typically features no UV component and research indicates that while lower UV components attract fewer invertebrates, warmer colour temperatures with peak wavelengths greater than 550nm (~3000°K) cause less impacts on bats’ (Bats and artificial lighting
in the UK – ILP/BCT)
- Some bat species are negatively affected from a Lux level as low as 1.9 lux (as a comparison sunset is 10 lux and a full moon is a maximum of 1.0 lux) so reducing lighting as much as possible, or lighting only one facade or lower extremities of a church would be beneficial to bats.
- You can contact your Parish and request that Parish Halls and Parish Churches are not lit up at night time, or lighting regimes altered to be more ‘bat friendly’.
- Personally – you can turn off exterior lights at night time, install a shield to reduce light spill or place lights on light sensors. If you do need lighting at night time then consider using the minimum light required for the task and a warm light colour.
- Specific guidance documents for lighting: Eurobats: Guidelines for consideration of bats in lighting projects and also BCT/ILP: Bats and artificial lighting in the UK
References and further reading for interest:
Avalon C.S.Owens, Précillia Cochard, Joanna Durrant, Bridgette Farnworth, Elizabeth K. Perkin and Brett Seymour ‘Light pollution is a driver of insect declines’ (2019) Biological Conservation https://doi.org/10.1016/j.biocon.2019.108259 article in press accessed 09/12/2019
Bats.org.UK, ‘Guidance Note 08/18 Bats and artificial lighting in the UK (2018)’ https://cdn.bats.org.uk/pdf/Resources/ilp-guidance-note-8-bats-and-artificial-lighting-compressed.pdf?mtime=20181113114229
Bats.org.UK ‘Lighting’ https://www.bats.org.uk/about-bats/threats-to-bats/lighting
Consideration of bats in lighting projects’ (2018) Publication Series No. 8 https://www.EUROBATS.org/sites/default/files/documents/publications/publication_series/WEB_DIN_A4_EUROBATS_08_ENGL_NVK_28022019.pdf
Cpre.org.UK, ‘Night Blight: Mapping England’s light pollution and dark skies’ (2016) https://www.cpre.org.uk/wp-content/uploads/2019/11/Night_Blight.pdf
Darksky.org ‘Lighting, crime and safety’ https://www.darksky.org/light-pollution/lighting-crime-and-safety/
Emma Louise Stone, Gareth Jones and Stephen Harris ‘Street Lighting Disturbs Commuting Bats’ (2009) 19 (13) Current Biology 1123 1127
EUROBATS.org, ‘Guidelines for consideration of bats in lighting projects’ (2018) Publication Series No. 8 https://www.EUROBATS.org/sites/default/files/documents/publications/publication_series/WEB_DIN_A4_EUROBATS_08_ENGL_NVK_28022019.pdf
Joanna K. Haddock, Caragh G. Threlfalla, Bradley Law and Dieter F. Hochulia ‘Light pollution at the urban forest edge negatively impacts insectivorous bats’ (2019) 236 Biological Conservation 17 28
Zhiyong Hu, Hongda Hu and Yuxia Huang ‘Association between night time artificial light pollution and sea turtle nest density along Florida coast: A geospatial study using VIIRS remote sensing data’ (2018) 239 Environmental Pollution 30 42