EIA Quality Mark: Mitigating the impacts of artificial lighting on wildlife

23rd November 2018

Web lights wildlife istock 545463346

Related Topics

Related tags

  • Built environment ,
  • Planning ,
  • Wildlife & Habitats


Iba Zupancic

Light spill from development can have significant impacts on light-sensitive species such as invertebrates, bats and birds. Steve Maguire and Alison Carroll review the issue.

The significance of lighting as an issue for wildlife is highlighted in publications prepared by organisations such as the Bat Conservation Trust1 (BCT) and Buglife2. These note the increase in the distribution and intensity of artificial light during the past few decades, and its potential to significantly disrupt species and ecosystems. The need to carefully consider lighting as part of development proposals is recognised.

Impacts on species vary. Artificial light can disturb invertebrate feeding, breeding and movement, which may reduce and fragment populations. Invertebrates, such as moths, can also be attracted to lights and it has been estimated that as many as a third of flying insects will die as a result of their encounter2. Lighting can also disrupt daily rhythms: birds have been noted singing by the light of a street lamp1. The detrimental impact of lighting on bats is also well recognised. Light falling on a bat roost exit point, regardless of species, will delay bats from emerging, which shortens the amount of time available to them for foraging; bats may even abandon the roost. Lighting can also affect feeding behaviour and commuting, with continuous lighting along roads creating barriers that some bat species cannot cross1.

The importance of the issue is recognised in planning policy and decision-making. The National Planning Policy Framework3 (NPPF) notes that development should “limit the impact of light pollution from artificial light on local amenity, intrinsically dark landscapes and nature conservation”. Additionally, there is an accompanying Planning Practice Guidance document on Light Pollution4, and local level policies also apply. For example, Bath and North East Somerset Council (B&NES) Policy D8 expects new developments to “reduce or at best maintain existing light levels to protect or improve the darkness of rivers, watercourses or other ecological corridors” 5, while the B&NES Environment and Design team has issued planning guidance relating to light spill along the city’s waterways6. The Torbay Local Plan7 includes a requirement for development within the Brixham strategic delivery area to provide mitigation measures to ensure “no increase in lighting in bat flyways to greater than 0.5 lux” (Policy SDB1).

The recent Eurobats publication on bats and lighting8 highlights the responsibility of the various EU member states to consider the impacts of lighting on bats and provides an in-depth review of research carried out on the subject. It also provides examples of planning context, assessment requirements and mitigation.

In recent years we have worked on a number of projects where lighting has been a potentially significant issue. This has been particularly the case for development projects along the River Avon in Bath. The key ecological issues included the designation of the River Avon as a Site of Nature Conservation Importance (SNCI) and its use as an important habitat for bats, linking with the Bath and Bradford on Avon Bats Special Area of Conservation (SAC). Early survey work and detailed liaison with B&NES, Natural England and lighting engineers highlighted the need for sensitive riverside edge treatments and carefully considered lighting schemes to minimise lighting impacts on important habitats. Mitigation measures have included habitat creation and enhancement through improved riverside planting and the provision of replacement bat roosts. Inclusion of a detailed lighting strategy at an early stage was key in avoiding unnecessary delays and setbacks.

Our experience has highlighted the importance of working with lighting engineers with an understanding of the potential effects on wildlife and how to mitigate these through sensitive lighting schemes. Considerations include the location, height, direction, timing and type of lighting used. While the Institute of Lighting Professionals has produced guidance on the reduction of obtrusive light9, undertaking environmental lighting impact assessments10 and the impact of obtrusive lighting on bats11 (co-authored with the BCT), specialist site-specific advice relating to wildlife must also be considered.

Steve Maguire is a senior ecologist at Nicholas Pearson Associates. Alison Carroll MIEMA CEnv is an associate at Nicholas Pearson Associates and a Registered EIA Practitioner


1 Bat Conservation Trust, 2014. Artificial Lighting and Wildlife. Interim Guidance: Recommendations to Help Minimise the Impact of Artificial Lighting

2 Buglife, 2011. A Review of the Impact of Artificial Light on Invertebrates

3 Ministry of Housing, Communities and Local Government, 2018. National Planning Policy Framework. Cm 9680 4 Ministry of Housing, Communities and Local Government, 2014. Light Pollution

5 Bath and North East Somerset Council, 2017. Placemaking Plan

6 Bath and North East Somerset Council, 2018. Protecting Bats in Waterside Developments

7 Torbay Council, 2012. Torbay Local Plan 2012 to 2030

8 EUROBATS Advisory Committee, 2018. Publication Series No. 8: Guidelines for Consideration of Bats in Lighting

9 Institution of Lighting Professionals (2011) Guidance Notes for the Reduction of Obtrusive Light. GN01:2011 10 Institution of Lighting Professionals (2013) Guidance on Undertaking Environmental Lighting Impact Assessments. PLG04:2013 11 Institution of Lighting Professionals & Bat Conservation Trust (2018) Bats and Artificial Lighting in the UK. Guidance Note 08/18

Image credit: iStock


Subscribe to IEMA's newsletters to receive timely articles, expert opinions, event announcements, and much more, directly in your inbox.

Transform articles

Renewables account for almost half of Britain’s power generation

Solar power generation hit a new high in the last quarter as renewables accounted for almost half of Britain’s energy production, according to a report from Montel Analytics.

18th July 2024

Read more

Ahead of the UK general election next month, IEMA has analysed the Labour, Conservative, Liberal Democrat, and Green Party manifestos in relation to the sustainability agenda.

19th June 2024

Read more

Sarah Spencer on the clear case for stronger partnerships between farmers and renewable energy developers

6th June 2024

Read more

A system-level review is needed to deliver a large-scale programme of retrofit for existing buildings. Failure to do so will risk missing net-zero targets, argues Amanda Williams

31st May 2024

Read more

Chris Seekings reports from a webinar helping sustainability professionals to use standards effectively

31st May 2024

Read more

Although many organisations focus on scope 1 and 2 emissions, it is vital to factor in scope 3 emissions and use their footprint to drive business change

31st May 2024

Read more

Joe Nisbet explores the challenges and opportunities of delivering marine net gain through offshore renewables

31st May 2024

Read more

IEMA submits response to the Future Homes Standard consultation

31st May 2024

Read more

Media enquires

Looking for an expert to speak at an event or comment on an item in the news?

Find an expert

IEMA Cookie Notice

Clicking the ‘Accept all’ button means you are accepting analytics and third-party cookies. Our website uses necessary cookies which are required in order to make our website work. In addition to these, we use analytics and third-party cookies to optimise site functionality and give you the best possible experience. To control which cookies are set, click ‘Settings’. To learn more about cookies, how we use them on our website and how to change your cookie settings please view our cookie policy.

Manage cookie settings

Our use of cookies

You can learn more detailed information in our cookie policy.

Some cookies are essential, but non-essential cookies help us to improve the experience on our site by providing insights into how the site is being used. To maintain privacy management, this relies on cookie identifiers. Resetting or deleting your browser cookies will reset these preferences.

Essential cookies

These are cookies that are required for the operation of our website. They include, for example, cookies that enable you to log into secure areas of our website.

Analytics cookies

These cookies allow us to recognise and count the number of visitors to our website and to see how visitors move around our website when they are using it. This helps us to improve the way our website works.

Advertising cookies

These cookies allow us to tailor advertising to you based on your interests. If you do not accept these cookies, you will still see adverts, but these will be more generic.

Save and close