The Vieux-Fort River marsh is a beautiful site with remarkable flora and fauna that must be preserved. Despite the presence of a road and its riprap, which have a significant impact on the environment, the site has been little affected by human activity. However, this environment, which consists mainly of a mangrove ecosystem, is facing an imbalance caused by desalination of the environment.
A preliminary assessment carried out in March 2024 showed that the salinity of the mangrove at several measurement points is mostly close to 0‰. However, salinity values below 5‰ are attributed to freshwater environments.
This situation is mainly due to the disruption of ecological continuity between the sea and the river caused by the presence of a coastal road and riprap. Although part of the river mouth has been preserved, the presence of these structures prevents connection between the environments, particularly due to sediment accumulation at the mouth. This initial disruption could be compounded by an excessive inflow of freshwater from urbanised and agricultural catchment areas. This imbalance results in a decrease in the resilience of the mangrove and the competitiveness of mangrove trees in relation to the barrel vine, which proliferates in the environment to the detriment of mangrove trees. In fact, under salinity conditions favourable to mangroves, the barrel vine, a native species dependent on coastal environments such as transitional ecosystems, is in equilibrium with the mangrove and does not spread to the detriment of mangrove trees.
In addition, the softening of the environment could allow the establishment of new freshwater species, including some invasive exotic species that border the site.
The main objective of the project is to restore the ecological balance of the environment by promoting an increase in salinity in the mangrove.
Duration: 24 months
