Artificial Light Impacts on Coastal Ecosystems (ALICE)

Lead Research Organisation: Plymouth Marine Laboratory
Department Name: Plymouth Marine Lab

Abstract

Coastlines are illuminated with artificial light at night (ALAN) from piers, promenades, ports harbours, and dockyards. Artificial sky glow created by lighting from coastal settlements can now be detected above 22% of the world's coasts nightly, and will dramatically increase as coastal human populations more than double by year 2060. Life history adaptations to the moon and sun are near ubiquitous in the upper 200m of the sea, such that cycle's and gradients of light intensity and colour are major structuring factors in marine ecosystems. The potential for ALAN to reshape the ecology of coastal habitats by interfering with natural light cycles and the biological processes they inform is increasingly recognised.

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 at >100m depth, 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 web's, changing ecosystem structure. The potential for coastal ALAN to disrupt marine organisms, species interactions, population dynamics, and organism distributions is clear.
The growing use of white Light Emitting Diodes (LEDs) (69% of global lighting by 2020) will exacerbate ALAN's impacts. LEDs emit more blue wavelength light that: i) penetrates deeper into seawater compared to older lighting technologies; and ii) many marine organism responses are most sensitive to. Tailoring LEDs to avoid blue wavelengths represents one mitigation option trialled on land that can be improved by investigating the spectral dependence of biological responses.
ALICE will tackle fundamental gaps in our understanding of marine ecosystem responses to ALAN, by carrying out the following research: -
1. Laboratory experiments to determine the impacts of ALAN on coastal organisms: Parallel experiments will quantify the impacts of ALAN interference with natural light cycles on the life history responses of marine invertebrates. These relationships will be used to model the growth rate of marine invertebrate populations exposed to different intensities of cool white LED light assuming optimal conditions with no predators or competitors.
2. Laboratory experiments to determine the impact of ALAN on species interactions: The relationships between white LED light intensity, and species interactions (predation,competition and mutualism) will be simultaneously quantified during the above experiments, and used to model the impacts of ALAN on marine invertebrate populations accounting for their relationships with one another in nature.
3. Mapping and modelling the distribution of ALAN in coastal marine habitats: The intensity of colour composition of ALAN in coastal waters will be mapped across three contrastingly urbanised UK estuaries. These data, and associated optical modelling, will be used with satellite data to globally map ALAN intensity from the sea surface to a depth of 100m.
4. Modelling ALAN impacts on species distributions: The population models (1,2) and the ALAN distribution model (3), will allow a synthesis assessment of long term changes in species distributions that may result from ALAN impacts.
5. Quantifying the benefits of avoiding ALAN wavelengths: we will quantify the ecological benefits of: i) removing blue light form LEDs blue using optical filters; ii) replacing white, with longer wavelength Amber LEDs. In addition we will quantify the responses of marine invertebrate larvae to different colours of light, so that the design of ecologically friendly LED lighting can be better informed.

Planned Impact

ALICE will target four distinctive groups of stakeholders in order to maximise the impact of the project. These will be: 1) conservation organisations; 2) the outdoor lighting industry; 3) the aquarium, agriculture and aquaculture industry and; 4) the general public.
Importantly, to maximise impact, ALICE will hold a series of five one-day structured workshops to facilitate knowledge transfer to and between our project partners from marine conservation, coral reef management, lighting industry and public outreach organisations to co-design ecologically sustainable lighting practices and technologies. Specifically, ALICE will use a real-life test case within the North Devon UNESCO site where the project science team, conservationists and industry can co-design technological solutions with the knowledge gained from the project.
The knowledge gained will be presented in a detailed report summarised by 'codes of best practice', for publication and wider circulation across project partner networks.
1) We will ensure that the outcomes of ALICE will be considered by governmental and non-governmental conservation organisations, particularly those concerned with the EU Marine Strategy Framework Directive descriptor 11 (Energy - which includes light, and noise) and achieving Good Environmental Status by 2020 are engaged with ALICE as project partners from the proposal writing stage (Natural England; Natural Resources Wales; North Devon UNESCO Man and Biosphere Reserve; The Society for the Protection of Nature in Israel; Israel Nature and Parks Authority and the Mideast Coral Reef Society).
2) We will engage with the outdoor lighting industry is increasingly aware of the ecological concerns associated with the use of white LED lighting which is popular in maritime industries. ALICE will capitalise on established relationships between the science team and major players in the UK lighting industry including the Institution of Lighting Professionals (representing the whole UK lighting industry), Kingfisher Lighting (developer of ecologically friendly lighting technologies), and Lighting Technology Products (exterior lighting architects whose coastal projects include the O2 Arena London, Dragon Bridge in Rhyl, and Bristol harbourside).
3) ALICE will build on established relationships with project partner Tropical Marine Centre (London) in order to create the most advanced indoor natural lighting solutions for aquarists, aquaculture, indoor farmers and scientific laboratories. This will use Java translations of Davies' existing lunar sky brightness models and recent advances on the CIE standard model, will allow the team to fully simulate moon and sun light irradiance and spectra in real time for any location on Earth using TMC's existing lighting control technology.
4) Coral reefs are ideally suited to communicate marine conservation topics to the general public as members are increasingly aware of the significance of reefs among the biologically most diverse ecosystems and the associated importance for humanity. The concern about the potential loss of the reefs is correspondingly high. We will therefore communicate our progress in providing a scientific knowledge base for marine conservation to a large public audience will be reached via the established Communication channels of the Horniman Museum, London previously utilised by Co-Is Wiedenmann and D'Angelo, including "Project Coral" headed by project partner Jamie Craggs.
Finally, all ALICE project outputs will be publicised in the global media (online, print, television and radio) using the science teams' respective press offices'. A website will inform the public about coastal light pollution and the ALICE project, contain an archive of published scientific outputs including an interactive global map of marine light pollution, links to online data repositories, and dedicated web pages to the impact plan.

Publications

10 25 50