Science & Tech · Science & Environment · 5 hrs ago
Artificial light puts Europe’s coastal seas at higher risk
Researchers mapped artificial light reaching European seas from coastal towns and offshore installations.
The Adriatic, Baltic and western Mediterranean had the highest overall exposure, while waters around Iceland, the Barents Sea and Macaronesia had the lowest.
The team used satellite data and a light level known to affect light-sensitive copepods, tiny crustaceans that move through the water at night.
Under the study’s rules, light reaching deeper than 10 metres counts as high risk, while nearly all waters more than 100 kilometres offshore were classed as having no risk.
Coastal waters face the greatest exposure: 73% of the western Mediterranean’s coastal waters and 56% of the Adriatic’s were classed as high risk.
In the Greater North Sea, offshore oil and gas platforms create an exception, with some distant waters also rated medium or high risk.
The map estimates potential exposure, not harm measured in marine animals; the researchers developed it to help address a lack of tools for European regulators.
Artificial light from coastal towns and offshore installations can penetrate Europe’s seas and may disrupt marine life.
A new risk map identifies the Adriatic, the Baltic and the western Mediterranean as among the most exposed regions.
The map uses satellite data and a light threshold based on measurements from a light-sensitive marine animal.
The study assesses exposure risk, not whether animals have been harmed.
- Who
- A research team led by Thomas Davies of the University of Plymouth, with Tim Smyth of Plymouth Marine Laboratory and colleagues in Britain and Italy.
- What
- The team mapped the risk of underwater artificial light exposure in European seas.
- When
- The article was published on 27 October 2026. The study date is not stated.
- Where
- Europe’s seas, including the Adriatic, the Baltic, the western Mediterranean and the Greater North Sea.
- Why
- The team aimed to develop a way to measure underwater light pollution risk, which European regulators had lacked.
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- Threshold
- A tenth of a microwatt of white light per square meter
- Adriatic coastal waters
- Within 10 kilometers of the coast, 56% was classified as high risk and 43% as moderate risk
- Western Mediterranean coastal waters
- 73% was classified as high risk
- Far offshore
- Beyond 100 kilometers from shore, nearly all European seas were classified as having no exposure risk
- Greater North Sea
- Beyond 100 kilometers from shore, a fifth of the water rated medium risk and 5% high risk
What people are saying
What is interesting is that most European Seas at high or moderate risk are small and bounded by developed coastlines around their periphery, the Adriatic for example
In those regions the maximum exposure risk is concentrated near the coast.