These measures can save energy, money and reduce the environmental impacts of marine light pollution.
Artificial light at night: the hidden threat to our ocean
The impact of marine light pollution and management options
Beyond the night sky, what is the impact of light pollution?
We know artificial light harms nocturnal wildlife, but it also affects 2 million km2 of ocean and 22% of coastlines. Artificial light from cities, ports, and offshore sites creates skyglow, making marine ecosystems 100 times brighter than moonlight.
Coastal populations will double by 2060, increasing this exposure.
Recognised by the UN Ocean Decade (2030 Vision White Paper) and aligned with UN Sustainable Development Goal 14 (Life Below Water), marine light pollution is an emerging global concern.
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<Two million square kilometres of the world’s oceans are exposed to light pollution
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a22% of our coastlines are exposed to light pollution
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cCoastal populations are set to double by 2060
Are LEDs really eco-friendly?
80% of global lighting uses LEDs, and they are often praised for energy efficiency. However, blue-wavelength LEDs penetrate deeper underwater – over 100 metres, and this light pollution affects marine life far more than older lighting technologies. Artificial light at night is polluting our seas and affecting animals' ability to 'see' their environment, hunt, hide, communicate, navigate, grow and reproduce.
While LEDs save energy, their excessive coastal use is harming marine life on an unprecedented scale.
How does light pollution harm marine life?
Artificial light at night disrupts natural cycles for marine life, affecting their navigation, reproduction, communication and food chains.
These changes can be seen up to 100 km away due to artificial skyglow.
The impact is sufficient for other species in the marine food webs to be impacted, and to change the composition of the whole marine ecosystem.
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GDisrupts zooplankton migration, affecting food chains and carbon sequestration
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GInterferes with coral spawning, endangering reef ecosystems
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GDisorientates sandhoppers, threatening coastal species
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GConfuses sea turtle hatchlings and their journey to safe seas
Artificial skyglow suppresses the diel vertical migration of marine zooplankton and affects their development and growth
An illustration of how a Littorinid snail loses the benefit of camouflage under broad spectrum lighting (right)
Creatures such as the sand hopper orientate their nightly migrations based on the moon's position and brightness of the natural night sky
Managing marine light pollution: what are the solutions?
Turning lights off eliminates pollution but, where lighting is needed, there are other options:
- Remove unnecessary artificial light
- Use dim and part-time lighting
- Prevent light spill through better design
- Adjust colour to reduce the impact.
The UK-led Global Ocean Alliance aims to protect 30% of oceans by 2030 ('30by30'), but marine light pollution remains unregulated in the UK Marine Strategy.
What policies are needed to regulate light pollution?
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HRecognise light pollution under Descriptor 11 of UKMS – the ̽»¨ÊÓƵ is developing the methodology for defining these criteria for the EU
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HRequire impact assessments for offshore developments
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HInclude marine species in coastal planning applications
Contact us for further information and guidance on establishing policy actions to combat marine light pollution and meet the 30by30 target.
Driving the strategy on the global stage to tackle marine light pollution
Ecologist
Dr Thomas Davies
, Associate Professor of Marine Conservation at the ̽»¨ÊÓƵ, 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 ̽»¨ÊÓƵ 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 , 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.
