Light Pollution

Sea turtles use light to orient themselves toward the ocean. In natural conditions, they are attracted by the night’s luminosity reflected in the ocean and are repelled by the darkness of the vegetation behind the beach. At Pointe Denis, lights on houses constitute a threat to turtles’ survival. In fact, artificial lights, placed behind beaches, have an intensity that is stronger than natural light (especially when the moon is absent). These lights can attract nesting turtles into unsuitable nesting sites and can disorient them after nesting. Hatchlings can also become lost upon leaving the nest. Thus, over the course of a single season, 71 adult females became stranded on the Pointe Denis savannah, and hundreds of hatchlings were victims of dehydration or predators (crabs, storks, monitor lizards, mongooses, stray dogs…) because they were not able to re-orient themselves onto their path to the sea.

Over the past four years, scientific studies were undertaken to understand this phenomenon and also to find solutions. Thus, we have discovered that it is not only the lights of Pointe Denis but also those of Libreville that disorient the hatchlings. A detailed study has indicated that orange neon lighting is less disturbing to adults and hatchlings than ordinary white neon. We are also looking to test amber and red-coloured LED lighting.

While waiting for these results, we haven't been inactive! We have been raising awareness about this problem with the residents and visitors to Pointe Denis (distribution of brochures, lighting diagnostics and advice…). In addition, the houses that have exterior lights that could disturb turtles were identified and we have implemented modifications in order to attenuate this pollution (installation of light-shades, orange filters, redirection of spotlights, removal of certain lights, etc.). Of 15 identified properties, 11 are now invisible to the eyes of turtles at night, and we are working on the remaining 4!

An Effective Dune

Since we built an artificial dune on Pointe Denis, NO turtles have been stranded on the savanna behind it!

A Shady Solution

Although replacing your current light bulbs with orange or red ones is best, placing a shade or filter over exterior lights is another way to make your beach home turtle-friendly.

Changing Lights

All 11 of the properties we have approached to change their lights to turtle-friendly ones have agreed to the change!

Hatchling Study

Our study confirmed that orange neon light is less disturbing to hatchlings than white neon light.