Guadeloupe and Martinique: Fuchsia Pink Mangroves Signal Troubling Developments

The cause of this color? Global warming. The observatory indeed explains that the hot weather “cause an evaporation of water which leads to an increase in the salinity of the mangrove ”. Therefore, the pH and the water temperature increases, while the oxygen level in water decreases.

The proliferation of Dunaliella Salina in the mangroves

These special and stressful conditions for many organizations are on the contrary particularly favorable to the proliferation of an algae, Dunaliella Salina. According to the observatory, we then speak of “Bloom Alglal”. The more oxygen drops, the more this algae is adorned with a pigment responsible for its pink color, beta-carotene.

It is therefore this significant proliferation which grants its pink shade to dark waters. If this phenomenon is increasingly frequent, the observatory specifies that it is temporary. With the return of the rainy season, the salinity rate decreases thanks to fresh water and pink gives way to the dark shades characteristic of mangroves.

Underwater crèches

If the pink of the mangroves attracts the curiosity of tourists as well as premises, it is also a good indicator of the “state of health” of the mangrove and therefore that of local biodiversity. Indeed, the mangroves play a key role for the ecosystem.

They are an important shelter for multiple life forms, such as fish and other small crustaceans. It is a kind of “underwater crèche” according to the expression of Guadeloupe National Park.

Today there are less than half of the original mangrove forest cover. This forest based on paletviers, which grows in the “Tropical coastal vase”(Larousse), also filters organic matter and makes it possible to limit floods.