The results obtained by the more than two hundred photometers deployed by the Interreg EELabs project over the last four years have been used to assess the impact of artificial light at night on the nocturnal ecosystems of the archipelagos – especially seabirds – but also to raise public awareness of the consequences of this type of pollution.
In Macaronesia, natural darkness is only preserved in very isolated nature reserves such as Corvo or Graciosa Island (Azores), Alegranza (Chinijo Archipelago, Canary Islands) or protected by law such as the Roque de Los Muchachos National Park (La Palma, Canary Islands).
Since the Interreg EELabs project began at the end of 2019, 12 networks of photometers have been installed to monitor the natural darkness of the natural areas of the different archipelagos of Macaronesia. A total of 222 autonomous photometers, developed for this project, are distributed on the islands of Tenerife, La Palma, Madeira, Corvo, Flores, Gran Canaria, La Graciosa, Alegranza, Lanzarote, La Gomera, Fuerteventura, El Hierro, Ilhas Desertas, Graciosa and São Miguel. The information they collect is sent to the public portal IoT-EELab, so that the scientific and educational community can make use of it.
The first conclusions are clear: natural darkness is only preserved in very isolated nature reserves such as the islands of Corvo or Graciosa (Azores), Alegranza (Chinijo Archipelago, Canary Islands) or protected by law such as the Roque de Los Muchachos National Park (La Palma, Canary Islands). The rest of the sites measured show an average Light Pollution Excess(LPE) of 40%.
“EELabs has provided a quantitative snapshot of light pollution in the main natural areas of Macaronesia. Although it is true that isolated places, such as Corvo, Graciosa or Alegranza, or protected by law, such as La Palma, preserve natural darkness, in general, light pollution is present in all the points measured. Special attention should be paid to the island of Gran Canaria. Of the 25 photometers installed in the municipality of Tejeda, the best darkness has been measured at the Parralillo Dam and yet it has an excess of light pollution of 48%. If we want to preserve the darkness of the Canary skies, it is necessary to regulate, in a sustainable way, the lighting of the large population centers, starting with the two capitals,” says Miquel Serra-Ricart, IAC researcher and project coordinator.
But the photometer networks – called Light Pollution Laboratories (LPL) – are also composed of MiNiOs controllers whose task is: on the one hand, to facilitate the sending of data from the photometers and, on the other hand, to send information on the meteorological conditions of the point where they are located.
Initially, the MiNiO controllers needed a power supply point to perform their functionality, but after the need to install them in protected natural areas arose, ITER, as a project partner, proposed the technical solution that best adapted to the physical, energetic and operational characteristics of these devices. The solution consisted of implementing a photovoltaic power supply system next to the device that provides energy autonomy throughout the year, or most of it, and that has allowed its installation in natural spaces taking advantage of the available solar resource. They started with the construction of a functional prototype that was tested at the Teide Observatory and later installed on the cable car of the Teide National Park. This equipment was used as a model for the construction of the following Autonomous MiNiOs that were installed in Madeira (Pico do Arieiro Natural Park) and in Greenland (Qaleraliq Glacier Front).
The results obtained by all these devices have given rise to a method for calibrating satellite images. This system is aimed at a more detailed assessment of light pollution. Satellite images are not sensitive enough to take accurate measurements in very dark areas, unlike photometers, which do not have this limitation. For this reason, the resulting map is extremely valuable, as it combines both sources and enables a very accurate analysis of nighttime brightness across the globe.
Impact on nocturnal ecosystems
Light pollution affects several species of seabirds and Macaronesia is home to 10 of them. Many of the youngest specimens of these species, attracted by city lights during their first flights, end up dying. Therefore, in the framework of the Interreg EELabs project, several volunteer initiatives have been carried out, which have resulted in the rescue of hundreds of birds; and thousands of schoolchildren in Madeira and the Azores have learned about this problem and act as ambassadors for the conservation of seabirds and dark skies, as a measure for the protection of biodiversity. The installation of photometers and the monitoring of Cory’s shearwaters using GPS devices have allowed us to learn more about how these birds interact with coastal lighting, as well as providing very important data on the ecology of this species. All these initiatives will be developed and continued in the LIFE Natura@night project.
In order to protect nocturnal ecosystems and the starry sky from artificial light at night, the municipalities of Güímar, Santiago del Teide and Mogán have committed to extend their regulations to protect the night through collaboration agreements in the framework of the Interreg EELabs project. These are the first municipalities in Macaronesia that have proposed to protect the natural darkness of the night through municipal ordinances, but new initiatives that are already underway, such as the LIFE Natura@night project, collaborate with many other municipalities willing to conserve nocturnal ecosystems under the slogan “For a night with more life”.
In addition to the commitment of public administrations, another very important part of the project has been to raise public awareness of the problem of light pollution. To convey the need to protect the darkness of the night, 25 rebroadcasts of celestial events, such as meteor showers, eclipses or auroras, have been made, in addition to the #UniverseAtHome series, which took place during the first weeks of confinement by COVID19. In addition to these videos, there are talks in educational centers, museums, open days and planetariums, and the film “The Dark Side”, also translated into Portuguese, to continue disseminating the importance of preserving the starry sky.
EELabs (eelabs.eu) is a project funded by the INTERREG V-A MAC 2014-2020 Program, co-financed by the ERDF (European Regional Development Fund) of the European Union, under contract number MAC2/4.6d/238. Five Macaronesian centers work in EELabs (IAC, ITER, ULPGC, SPEA-Azores and SPEA-Madeira). The objective of EELabs is to create Laboratories to measure the Energy Efficiency of Artificial Night Light in protected natural areas of Macaronesia (Canary Islands, Madeira and Azores).
The LIFE Natura@night project is co-funded by the LIFE program of the European Union, coordinated by SPEA, and has as partners the Câmara de Lobos, the Câmara Municipal do Funchal, the Câmara Municipal de Santa Cruz, the Câmara Municipal de Machico, the Câmara Municipal de Santana, the Câmara Municipal de Santa Cruz da Graciosa, Direção Regional dos Assuntos do Mar, Instituto das Florestas e Conservação da Natureza, Instituto de Astrofísica de Canarias, Instituto Tecnológico de Canarias, Fluxo de Luz and the Sociedad Española de Ornitología.
Scientific articles:
Alarcon, M.R., Serra-Ricart, M., Lemes-Perera, S. & Mallorquín, M. (2021). Natural Night Sky Brightness during Solar Minimum. The Astronomical Journal, Vol. 162, Num. 1. DOI: 10.3847/1538-3881/abfdaa
Alarcon, M.R., Puig-Subirirà, M., Serra-Ricart, M., Lemes-Perera, S., Mallorquín, M. & López, C. (2021). SG-WAS: A New Wireless Autonomous Night Sky Brightness Sensor. Sensors 2021, 21(16), 5590; https://doi.org/10.3390/s21165590.
Fernandez-Ruiz, B., Serra-Ricart, M., Alarcon, M. R., Lemes-Perera, S., Santana-Pérez, I., & Ruiz-Alzola, J. (2023). Calibrating nighttime satellite imagery with red photometer networks. Remote Sensing, 15(17), 4189. https://doi.org/10.3390/rs15174189
Relevant links:
EELab IoT data portal: https://data.eelabs.eu/
Light pollution map: https://data.eelabs.eu/map
