Light Pollution and Marine Ecosystem


    Syllabus: GS-3/Environment, Pollution


    • Light Pollution is a growing threat for marine ecosystems.

    What is Light Pollution?

    • It is the modification of natural light at night, caused by unwanted, inappropriate, or excessive anthropogenic artificial light sources. It’s a consequence of industrial civilisation and urbanization.
    • Building exterior and interior illumination, advertising, outdoor area lighting (such as car parks), offices, industries, street lights, and illuminated stadiums are some of its sources.
    • Moonlight and starlight serve as important cues for marine organisms and their glow can easily be washed out by artificial light. 

    Impact of Light Pollution on Marine Ecosystem

    • Marine organisms like coral reefs depend on natural light to regulate their physiological and biological processes. The maintenance of coral via the process of symbiosis is sensitive to artificial lighting.
      • Symbiosis describes the close relationship between the two organisms that make up coral.
    • The use of artificial lights at night to illuminate seafloor habitats can disrupt visually guided ecological processes. Predators that usually feed in the day such as the Herring Gull may be able to see prey at night, such as marine snails.
    • It also impacts the reproduction of fish and it can disorientate turtle hatchlings and affect their ability to reach the safety of the ocean.
      • Female turtles trying to find a quiet, dark spot to lay their eggs avoid light and may end up not coming ashore at all.
    • The daily migration of zooplankton, which are a key part of the marine food chain, can be disrupted by artificial light. It migrates every night from the bottom of the sea to the surface. But when there’s light pollution, they migrate much less.

    Steps Taken

    • In February 2020, the United Nations also adopted light pollution guidelines through the Convention on the Conservation of Migratory Species of Wild Animals, acknowledging that this is an emerging issue for both wildlife conservation and human health.
    • The use of red light is another way because it doesn’t penetrate deeper into the water. It’s even possible to put up barriers that would shield the coastline from artificial light.

    Source: DTE