Artificial Light in Coastal Ecosystems (ALICE)
Completed projectProject start: April 2019 | Project end: March 2023
Principal Investigator: Dr Tim Smyth
Other participants from PML: Christine Pascoe, Dr Liz Talbot, Joana Nunes, Thomas Mesher
Artificial light at night (ALAN) can now be detected above 22% of the world’s coasts, and will dramatically increase as coastal human populations more than double by year 2060, which has the potential to reshape the ecology of coastal habitats by interfering with natural light cycles and biological processes.
Marine invertebrates are extremely sensitive to natural light throughout their life cycle. Examples include synchronised broadcast spawning in reef corals informed by moonlight cycles, zooplankton sensitivity to moonlight, and phototaxis of larvae under light equivalent to moonless overcast nights. The reproductive, larval and adult phases of marine invertebrates are all affected by night-time lighting of equivalent illuminances to those found in ports and harbours. Further, direct impacts on organism behaviour can indirectly affect other species in coastal food webs, changing ecosystem structure.
The growing use of white Light Emitting Diodes (LEDs) is of particular concern as it may exacerbate ALAN's impacts. LEDs emit more blue wavelength light that penetrates deeper into seawater compared to older lighting technologies and many marine organism responses are particularly sensitive to.
ALICE will tackle fundamental gaps in our understanding of marine ecosystem responses to ALAN, by carrying out laboratory experiments to determine the impacts of ALAN on coastal organisms and their interactions, modelling the growth rate of marine invertebrate populations exposed to different intensities and wavelengths of light, and mapping and modelling the distribution of ALAN in coastal marine habitats.
By bringing together expertise in bio-optics, remote sensing, modelling and ecology ALICE will endeavour to assess the impacts of our humanity’s night-lights on the ocean and look for solutions to mitigate this impact.