Marine light pollution

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.

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 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 20^th 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 the use of them has resulted in more blue wavelength light that penetrates deeper into seawater.

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.

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 21^st 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).

Global Ocean Artificial Light at Night Network (GOALANN)

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.