“Pollux NC”: Assessing light pollution in New Caledonia

Light pollution is an understudied environmental pressure in New Caledonia, although it is likely to cause disturbances in the biological rhythm of plants, animals and humans. As a global biodiversity hotspot, the conservation issues are nevertheless major in this territory of the South Pacific.

BEST 2.0+ was very pleased to award the Environmental Observatory in New Caledonia (OEIL) a grant in July 2021 to implement “Pollux NC”. This project aims to provide the first quantified information on light pollution on the scale of New Caledonia and to issue scientific recommendations for its consideration in public policies.

In its final phase, Pollux NC is analysing and interpreting the data collected, before sharing the results with environmental stakeholders and with the general public in New Caledonia.

Source: Nouméa la nuit – © OEIL 2021

Why study light pollution in New Caledonia?

Conservation issues are of great importance in this South Pacific territory, which is one of the 35 global biodiversity hotspots, e.g., endemism rates of up to 80% for plants, more than 90% for lizards, 6 UNESCO World Heritage Sites and 1 site on the Ramsar list of Wetlands of International Importance. However, no characterization of light pollution on the scale of the country has yet been made, and the last map of the World Atlas, which is not very precise, was updated in 2015.

Our role as an observatory is to describe the environmental pressures exerted on the New Caledonian ecosystems, to evaluate their impact, and to identify what responses have been provided or could be provided“, specifies Anne Lataste, Scientific Communication Manager at OEIL. “Faced with growing urbanisation and active industrial and mining sites lit 24 hours a day, light emissions are an environmental concern that deserves to be better known to be managed sustainably”.

The president of the Caledonian Society of Ornithology (SCO), David Ugolini confirms: “Light pollution is a problem that we know well at the SCO about its harmful effects on bird populations, especially shearwaters and petrels. To address this problem, it is essential to get to the root of it, which is precisely the objective of Pollux, carried out by OEIL, with the support of our association.”

What does Polux NC pursue?

By the end of 2022, the project will have made it possible to take stock of newly-acquired knowledge, assess light pollution in New Caledonia, formulate recommendations for management measures, and raise awareness among decision-makers and the public.

With this study, we are laying down the preliminary framework for the integration of light pollution into public policies. We are at the crossroads of environmental issues, land use planning and low energy consumption”, continues Anne Lataste, “this is why our work, which may seem far from other current priorities, is fundamental”.

This may also be an opportunity for New Caledonia to engage the international narrative on this problem, thus joining other initiatives like International Dark Sky Reserves, or the Black Frames, which complements the Green and Blue Frames scheme initiated by the French Office for Biodiversity (OFB).

What data sources are used in the Pollux NC project?

First, free data from NASA satellites: with a coarse level of precision, a map of light pollution at the scale of the territory will be produced.

The picture below features a 2015 map of light emissions in New Caledonia obtained using satellite data from the Nasa VIIRS sensor – ©World Atlas 2015.

The picture below features a 2020 map of light emissions in New Caledonia obtained using satellite data from the Nasa VIIRS sensor Sources : Pollux NC / OEIL, Nasa

Secondly, the acquisition of very high-definition satellite images: a detailed analysis will be produced on the pilot sites selected by the steering committee of the project: the urban area of Païta – Dumbea – Mont-Dore and, thanks to the respective complementary contributions of the SCO and the municipality of Nouméa, the areas of Kaala-Gomen / Koumac in the Northern Province, as well as the city of Nouméa.

Thirdly, ground sensors: the CNES (Centre National d’Etudes Spatiales) and the company Dark Sky Lab have offered OEIL a partnership to deploy NINOX probes, a technology capable of measuring the darkness level of the night sky throughout the whole night cycle. The Pollux NC project will thus be able to benefit from this additional data while contributing to advancing research.

One year after its start, how is the Pollux NC project progressing?

The project is progressing according to the schedule and most of the tasks before the analysis have already been carried out, i.e. the bibliographical synthesis of current scientific knowledge on light pollution in New Caledonia and the world is done, and most of the required satellite images have been acquired “despite the difficult weather conditions provoked by La Niña phenomenon”, specifies Adrien Bertaud, Head of the Environment Division of OEIL and Pollux NC Project Manager. Our ability to get good quality images was a matter of concern for us for the first few months, and we are still missing some of them, but we are not giving up”.

In addition, NINOX ground probes for measuring the darkness of night cycles have been deployed at various locations in the territory. Their data must now be analysed and provide additional information to satellite images.

I think the biggest success of Pollux NC to date, even before it produces its final results, is the interest it has generated! The project was launched thanks to the support of the BEST 2.0+ with funding from the European Commission, and we are delighted about this. At the same time, the project has also taken on a whole new dimension thanks to the strong commitment of the Caledonian Society of Ornithology (SCO) and the city of Noumea, which was not planned from the beginning. This is very encouraging“, comments Fabien Albouy, Managing Director of OEIL.

Indeed, thanks to this collaborative approach, the project is involving relevant and motivated stakeholders within its steering committee. “I would add that we regularly receive spontaneous requests from scientists elsewhere in the world, from the local press and from other organisations, such as the Caledonian Astronomy Association, which has joined the steering committee. We have the feeling that this project was needed”, concludes Anne Lataste.

For more information:

Visit the project presentation page:
Watch the Caledinno episode on TV channel Nouvelle-Calédonie la 1ère here.