Mangroves in Flacq District

Poste Lafayette

• Narrow fringing belts along a rugged, rocky coastline.

• Features small, fragmented patches that struggle with higher wave energy but provide essential shoreline stability.

• Notable for being one of the few sites where the rarer Bruguiera gymnorrhiza can be found in small clusters. It is a wilder, more exposed coastal environment compared to the southern lagoons.

Bras D’Eau

• Part of a larger thriving ecosystem within the Bras D'Eau National Park boundaries.

• Includes the "Mare Sarcelle" sub-site, which covers nearly 90 hectares of coastal wetlands.

• One of the most pristine and well-managed stands on the island. It offers critical habitat for migratory birds and is a significant site for biodiversity monitoring.

Constance Prince Maurice-Poste de Flacq

• Extensive forest integrated within a natural coastal "barachois."

• High; adult trees show significant biomass and complex, arching prop roots.

• This site is managed as a protected fish sanctuary. The resort architecture is built around the mangroves, demonstrating a high level of integration between tourism and conservation.

Poste de Flacq North & South

• Continuous belts surrounding the estuarine areas of the village.

• High density of Rhizophora mucronata; essential for the local artisanal fisheries.

• These sites face ongoing pressure from residential expansion but remain one of the most culturally significant mangrove areas for the local fishing community.

Palmar

Palmar features smaller, more fragmented mangrove patches that are adapted to the sandy environment of this popular coastal stretch.

• Primarily exists as remnant, linear belts that fringe the edge of the lagoon and historical "barachois" systems.

• While less extensive than the forests of Trou d’Eau Douce, these patches are highly significant for local soil stabilization.

• These mangroves play a crucial role in preventing coastal erosion and stabilizing the sandy dunes that define the Palmar coastline.

Trou d’eau Douce

• Approximately 10,000 $m^2$ of natural forest.

• Features very high adult tree density, with counts reaching 11,000 per hectare.

• One of the largest natural patches in Mauritius. The trees reach heights of 2–7 meters, providing a dense canopy that serves as a primary nursery for the lagoon's fish populations.

Beau Champ

The region of Beau Champ serves as a critical estuarine environment where the Grand River South East (GRSE) interacts with the turquoise lagoon waters.

• Composed of significant estuarine patches that thrive in the nutrient-rich, brackish waters at the river's mouth.

• Highly abundant stands that are essential for trapping terrigenous sediment before it reaches the coral reefs.

• This site has been a primary location for scientific research on specialized fungi associated with dead mangrove prop roots, contributing to our understanding of the ecosystem's nutrient cycling.

Beau Rivage

• Fringing forests along the resort coastline.

• Moderate; mostly pure stands of Rhizophora mucronata.

• This site has been used in scientific research to study the spectral signatures of fringing forests and the "mixed pixel" effect in satellite imagery.

Mu Coast Alongside Ilot Margenie and Ile...

• Vibrant, narrow fringing forests lining the turquoise lagoon.

• High visibility; these belts provide a vivid green contrast to the white sands.

• Critical for preventing islet erosion on the seaward side of the lagoon.

Mu Coast - Ile aux Cerfs Lagoon

• Extensive stands surrounding the shallow, sheltered waters.

• High; provides a sanctuary for marine invertebrates and fish larvae.

• These mangroves act as natural filters, ensuring the clarity of the lagoon water which is essential for the region's coral health.

Ile de L’Est/Ilot Margenie & Islets

• Small landmasses often entirely surrounded by protective mangrove fringes.

• Dense clusters that serve as the primary defense against storm surges for these fragile islets.

• Often reachable only by boat, making these stands less disturbed by human activity.

Ile aux Cerfs & Islets

• Significant forest cover interspersed with sandy beaches and the island's interior.

• High; provides nesting sites for sunbirds and habitats for native geckos.

• A primary destination for eco-tourism; the ground-truthed maps here are vital to separate mangrove cover from other coastal vegetation.

La Place Belgath & Anahita and Islets

• Managed and preserved stands integrated into the luxury resort landscape.

• Consistent fringing patches that help maintain private lagoon water quality.

• Represents a balance between high-end development and ecological preservation.

Grand River South East (GRSE)

The estuary of the GRSE Waterfall is one of the most dynamic mangrove sites in Flacq, acting as a major interface between land and sea.

• Features lush, deep-reaching mangrove stands that line the arms of the island’s longest river.

• Provides a high-density habitat that serves as a primary nursery for juvenile fish and shrimp populations.

• The mangroves here are a highlight for eco-tourism and kayaking, offering a unique perspective on the arching prop roots that anchor the riverbanks against heavy seasonal flows.

Quatre Soeurs

• Stable and mature stands that benefit from riverine inputs.

• Part of a continuous belt that extends toward the South-East region.

• This area has been a major site for the propagation of seedlings to restore lost acreage, maintaining the traditional fishing heritage of the village.

In addition to the sites mentioned above, field surveys have identified the following ecologically relevant clusters:

• Petite Julie: Small estuarine patches that support localized bird populations.

• Belle Mare (Inland Fringes): Minor remnant clusters associated with the historic marshy areas behind the primary dune line.

Poste Lafayette

Barachois Constance - Poste de  Flacq - GRSE