Marine light pollution
Understanding and managing the impact of artificial light at night (ALAN) for healthy seas
Artificial light at night
Two million square kilometres of the world's oceans and 22% of coastlines are exposed to light pollution from offshore infrastructure and coastal towns and cities – together they form artificial skyglow that can expand the impact of light pollution to hundreds of kilometres offshore.
Artificial light at night (ALAN) is of growing concern as a pollutant to our seas. It disrupts the natural patterns and biological processes of marine life, including those that support critical ecosystem services. This includes animals' ability to see their environment – to hunt, hide, communicate, navigate, grow, time important events and reproduce.
The impacts of light pollution on the night sky, astronomy and land-based ecosystems are well studied – but until just over 10 years ago, the full extent of ALAN in our coastal waters, seas and oceans was unknown.
Skyglow is the most geographically widespread form of light pollution. Surveys have shown it can currently be detected above 23% of the world's coasts nightly and, with coastal human populations set to at least double by 2060, its effects are only going to increase.
Our results show it is already having demonstrable impacts on biological processes that are guided by celestial light cues.
Dr Thomas Davies
Associate Professor of Marine Conservation
Introducing the issue, driving the strategy
Ecologist Dr Thomas Davies, Associate Professor of Marine Conservation at the University of Plymouth, has been driving the strategy for marine light pollution research and mobilising policy action since he published the first paper on the topic in 2014.
More recently, working in partnership with Professor Tim Smyth at Plymouth Marine Laboratory, this research is now combining laboratory and field experiments with remote sensing to deliver insights into how changing lightscapes impact marine organisms and ecosystems.
As a co-founder of the UN Ocean Decade endorsed Global Ocean Artificial Light at Night Network (GOALANN), the University has been instrumental in providing the first central resource for the understanding and managing of marine light pollution through policy technology and behaviour.
Seeing blue
The lighting technologies of the early 20th century impacted the first 10 metres of our oceans. However, with the more recent introduction of blue wavelength LEDs, artificial light can now penetrate below 100 metres.
LEDs make up more than 80% of the global lighting market and, in the UK alone, have been rolled out across coastal cities and offshore infrastructure without consideration of the impacts on the marine environment.
Exponential growth in their use has resulted in more blue wavelength light that penetrates deeper into seawater.
Global Ocean Artificial Light at Night Network (GOALANN)
Endorsed by the United Nations Decade of Ocean Science for Sustainable Development as an Ocean Decade Action.
GOALANN is an international network of the world's leading experts in marine light pollution whose mission is to conserve the oceans by improving knowledge and awareness of marine light pollution, its ecological and societal impacts, and management options.
The initiative unifies research groups from around the world to provide a central resource of marine light pollution expertise, projects and tools for policy makers, environmental managers, maritime industries, the media and the public.
Key research projects
Artificial Light Impacts on Coastal Ecosystems (ALICE)
Tackling gaps in our understanding of marine ecosystem responses to ALAN
Aquatic Pollution from Light and Anthropogenic Noise (AquaPLAN)
Leading investigations into the impacts of light and noise on biodiversity
Documenting the impact
In the last decade, over 200 scientific papers have been published documenting the impacts of light pollution on marine species, from fish to coral and from the tropics to the poles.
Marine light pollution has been proven to:
- Suppress zooplankton migration, which negatively affects the food chain and carbon sequestration;
- Disrupt coral spawning, which subsequently reduces marine habitats;
- Upset the 'lunar compass' of coastal species, threatening the health of the sandhopper and the wider ecosystem it supports.
Dr Thomas Davies launches GOALANN at the UN Ocean Decade Conference, Barcelona 2024
Track the progress of our research and engagement
2014
- Led and published the first paper on marine light pollution.
2015
- Led and published first paper demonstrating that light pollution can reshape assemblages of marine organisms.
2016
- Led and published the first assessment of the extent of light pollution across the worlds network of marine protected areas.
2017
- Made the case for light pollution as a focal area for global change research in the 21st century.
- Led and published the first paper investigating how light pollution impacts predator–prey interactions between marine species.
- Led the Artificial Light Impacts on the Encroachment on Non-Native Species project as an Independent Research Fellow.
2018
- Founded and led the first UK consortium of marine research institutions investigating Marine Light Pollution in the Artificial Light Impacts on Coastal Ecosystems Project (2018–2024).
- Led and published the first paper demonstrating patterns of marine biodiversity associated with light pollution.
2020
- Led the first study that quantified the biological importance of artificial light prevalence on the seafloor and potential detrimental effect on marine life.
- Discovered 'artificial skyglow' has significant impact on coastal species that rely on the natural night sky.
2021
- Instrumental in the creation of the first global atlas of artificial light at night of our oceans and led the first appraisal of methods in marine light pollution research.
2022
- Instrumental in the first international review of marine light pollution impacts.
- Led the first examination of the effects of artificial light at night on camouflage mechanisms of coastal species.
2023
- Discovered coastal lights cause corals around the world to spawn earlier.
- Co-founded GOALANN.
2024
- Instrumental in securing support for and UK participation in the JPI Oceans Joint Action on 'Changing Marine Lightscapes'.
- Co-lead on the EU Horizon-funded Aquatic Pollution from Light and Anthropogenic Noise (AquaPLAN) project (2024–2028).
2025
- Secured UN Ocean Decade endorsement for GOALANN.
News
Marine light pollution science initiative endorsed by United Nations
The GOALANN network was conceived by experts at the University who led the first ever study into the impacts of marine light pollution
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Blinded by the light: the effects of urban lighting on beach bugs
A new study further enhances the University's reputation as a global leader on the ecological effects of light pollution
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Initiative increases awareness of the threats posed by light pollution to the global ocean
The Global Ocean Artificial Light at Night Network has been launched at the United Nations Ocean Decade Conference in Barcelona
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Coastal lights trick coral reefs into spawning earlier than they should
New research shows that corals exposed to artificial light at night are spawning one to three days outside of their optimum reproductive periods
- More related news
Further reading
Journal articles and news on the impact of artificial light at night
- The nature, extent, and ecological implications of marine light pollution (Frontiers in Ecology and the Environement)
- A global atlas of artificial light at night under the sea
- Global disruption of coral broadcast spawning associated with artificial light at night
- Impacts of artificial light at night in marine ecosystems – A review (Global Change Biology)
- Why artificial light at night should be a focus for global change research in the 21st century (Global Change Biology)
- 11 pressing research questions on how light pollution affects biodiversity (Frontiers in Ecology and Evolution)
- Artificial skyglow disrupts celestial migration at night
- Biologically important artificial light at night on the seafloor (Nature)
- Night-time lighting alters the composition of marine epifaunal communities (Biology Letters)
- Artificial light at night alters trophic interactions of intertidal invertebrates (Journal of Animal Ecology)
- Crustacean photoreceptor damage and recovery: Applying a novel scanning electronic microscopy protocol in artificial light studies (Science of The Total Environment)
- Impacts of artificial light at night on the early life history of two ecosystem engineers (Philisophical Transactions of the Royal Society B)
- Artificial light at night alters predation on colour-polymorphic camouflaged prey (Basic and Applied Ecology)
- Artificial light at night (ALAN) disrupts behavioural patterns of reef corals (Marine Pollution Bulletin)
- Disruption of marine habitats by artificial light at night from global coastal megacities (Elementa)
- Artificial light at night reverses monthly foraging pattern under simulated moonlight (Biology Letters)
- Broad spectrum artificial light at night and camouflaged prey
- Marine artificial light at night: An empirical and technical guide (Methods in Ecology and Evolution)
- Artificial skyglow disrupts celestial migration at night (Current Biology)
- Mapping the consequences of artificial light at night for intertidal ecosystems (Science of the Total Environment)
- Impacts of artificial light at night on biological timings (Annual Review of Ecology, Evolution, and Systematics)
- Stemming the Tide of Light Pollution Encroaching into Marine Protected Areas (Conservation Letters)
- Human alteration of natural light cycles: causes and ecological consequences (Springer Nature Link)
- Reducing the ecological consequences of night‐time light pollution: options and developments (Journal of Applied Ecology)
- Artificial light alters natural regimes of night-time sky brightness (Scientific Reports)
- Artificial light pollution: are shifting spectral signatures changing the balance of species interactions? (Global Change Biology)
- The ecological impacts of nighttime light pollution: a mechanistic appraisal (Biological Reviews)
Applications are currently open for the following PhD studentships:
For more information on our marine light pollution research, please contact
Dr Thomas Davies
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