Coastal Erosion (Mauritius)

Impacts of Coastal Erosion

• Environmental: Loss of habitat for marine and coastal species, reduction in biodiversity, and degradation of coral reefs.
• Economic: Affects tourism, which is a significant part of Mauritius' economy, as well as property values and infrastructure along the coast.
• Social: Impacts the livelihoods of local communities who depend on the sea for their income, particularly in fishing and tourism.

Strategies for Mitigation

• Beach Nourishment: Artificially replenishing beaches with sand from other sources to counteract the effects of erosion.
• Protective Structures: Building sea walls, groynes, and breakwaters to protect the coastline.
• Mangrove Restoration: Encouraging the growth of mangroves which can help stabilize the shoreline and provide natural protection against storm surges.
• Restoration of vegetation in dunes:  The root systems of certain native plants help hold the sand in place, reducing erosion and providing a natural barrier against the impact of storms and waves.
• Regulation and Monitoring: Implementing strict regulations on coastal development and monitoring coastal changes to plan appropriate responses.

• 

Sites highly susceptible to erosion

In the short term, the erosion of Mauritius' coasts is primarily caused by intensive coastal development, sea level rise, coral reef degradation, and tropical cyclones, which generate large surges and waves when they pass close to or directly over the island. 

The national tourism strategy predicts that by the century's end, half of the country’s beaches will be eroded to the extent that they can no longer accommodate visitors, resulting in significant economic losses. Additionally, the loss of coastal areas not only means a loss of habitat for flora and fauna but also exposes previously protected inland areas to direct coastal hazards like storm surges, high tides, and strong winds.  

Quatre Soeurs Beach

Mon Choisy Beach

Description: One of the most popular beaches in Mauritius, Mon Choisy has experienced significant erosion over the years. The beach has been visibly reduced in width, impacting both tourism and the natural habitat.

Response:

• • Installation of 950 artificial reef (bombora dome) units ranging from (Diameter 2.1m and height 1.8 m) to (Diameter 1.8m and height 1.3 m)  
  • Beach re-profiling over 450 metres involving removal of 215 casuarina trees
  • Beach Embellishment Works including planting of sand binding plants
  • Rock Groyne removal 250 m²

• Restoration efforts include the installation of geotextile tubes and replanting of coastal vegetation to stabilize the shoreline and reduce further erosion.  About 950 concrete domes have been placed in rows to form the artificial reef.

Flic en Flac

• Description: This region has also seen considerable coastal erosion, with high tide marks moving progressively inland, impacting local infrastructure and beachfront properties.
• Response: Measures such as building groynes and sea walls have been implemented to help retain sand and protect the coast.  However, the  construction of groynes for Flic en Flac were found to exacerbate erosion (Doorga et al, 2021).

Rivière des Galets

• Description: Known for its pebbly beach, Rivière des Galets is particularly vulnerable to erosion during cyclones and high swells, which can remove significant amounts of beach material.
• Response: Local authorities have undertaken ad-hoc measures like the placement of rock armors to protect specific areas from further erosion.  

• Construction of a Rock Revetment of length of 430 metres
• Construction of a concrete parapet wave-return wall
• Walkway landward of the structure
• Installation of solar lighting
• landscaping works

Rock Embankment

Grand Sable

BEFORE

AFTER

BEFORE

AFTER

Le Morne Public Beach