Important Definitions

Coastal zones

Environment Act 2024  (section 84) defines the ‘coastal zone’ as follows:

(a) means any area which is situated within one kilometre or such other distance as may be prescribed from the high water mark, extending either side into the sea or inland; and

(b) includes –

(i) coral reefs, reef lagoons, beaches, wetlands, hinterlands and all islets within the territorial waters of Mauritius and Rodrigues;

(ii) any estuary or mouth of a river and that part of a river, stream or canal which lies within one kilometre from the outermost point of its bank on the sea at high tide;

(iii) the islands of Agaléga and Saint Brandon, and other outer islets; 

State Lands

"State land" includes defence lands, 'Pas Géométriques' and all lands belonging to or in possession of the State. State Lands Act (Cap. 224) governs the ownership, leasing and management of State land in Mauritius, including Pas Géométriques, defence lands, river and mountain reserves. Such lands are generally inalienable and cannot be acquired by prescription (Section 35). Amendments in 2024 allow increased residential plot purchases for existing lessees and enable private leasing of vested barachois by the Minister of Fisheries. The 2025 Regulations permit eligible residential lessees (up to 25 perches) to buy plots for Rs 2,000. State land is leased at full rental value, subject to strict environmental protection and enforcement provisions. 

Pas Géométriques

The Pas Géométriques Act of 1895 is a fundamental piece of Mauritian legislation that governs the "Pas Géométriques"—a narrow strip of state-owned land extending along the entire coastline of Mauritius. The strip is defined as reserved land starting from the high-water mark at spring tide and extending inland to a breadth of 81.21 metres (roughly 250 French feet). These lands are part of the "public domain" and are declared inalienable and imprescriptible. While the land cannot be sold, the Minister responsible for lands can grant leases for various purposes, including campements (seaside bungalows), hotels, agriculture (like coconut plantations), and, as per the Pas Géométriques (Amendment) Act 2024, the leasing of barachois (coastal fish ponds). Historically, the Act required lessees to plant and maintain trees (such as filaos) to prevent coastal erosion and protect the shoreline. The Act strictly prohibits unauthorized dumping, unauthorized cutting of trees, and illegal structures within this zone.

Public Beach

In Mauritius, public shorelines are governed by the Beach Authority Act 2002, which established the Beach Authority to manage public beaches across the Republic. Definition: "public beach"— (a) means a space along the coast which, by notice published in the Gazette, has been declared to be a public beach by the Minister to whom responsibility for the subject of lands is assigned; and (b) includes the space between the low-water mark and the high-water mark, and the surrounding waters up to a distance of 100 metres. The Authority oversees conservation, amenities, and safety. The Use of Public Beach Regulations 2004 regulate trading, vehicles, animals, swimming zones, and public events. While beaches are public up to the high-water mark, access across privately leased Pas Géométriques land is not guaranteed unless a public access is provided.

🌿 The Mangrove Glossary: A Guide to Coastal Sentinels

Welcome to our comprehensive guide to the language of mangroves. Often referred to as the "roots of the sea," mangroves are among the most complex and productive ecosystems on Earth. They exist in the challenging Intertidal Zone, where they serve as a bridge between terrestrial and marine biomes.

In an era of rapid climate change, understanding the terminology of these forests—from their specialized respiratory roots to their role in Blue Carbon sequestration—is vital for researchers, conservationists, and coastal communities alike. This glossary is designed to demystify technical scientific terms and standardize the acronyms used in global conservation policy.

🏛️ Section 1: Anatomy & Physiological Adaptations

The biological mechanisms that allow mangroves to thrive in saltwater and oxygen-poor soils.

• Aerenchyma: Spongy, air-filled tissue in roots and stems that allows for internal gas exchange in waterlogged, anaerobic environments.

• Aerial Roots: Roots that remain partially exposed to the atmosphere.

  • Pneumatophores: Vertical "snorkel" roots that emerge from the mud to breathe (common in Avicennia).

  • Prop/Stilt Roots: Arched supports extending from the trunk into the water (common in Rhizophora).

  • Knee Roots: Roots that loop above the surface like a bent knee, providing stability and aeration (common in Bruguiera).

• BGB (Below-Ground Biomass): The root systems and organic matter stored in the soil. In mangroves, BGB often contains significantly more carbon than the visible tree above.

• Lenticels: Microscopic pores on the surface of aerial roots that serve as the gateway for oxygen entry.

• Salt Excretion vs. Exclusion:

  • Excretors: Species that utilize specialized glands to pump salt out onto the leaf surface.

  • Excluders: Species that use ultra-filtration at the root-soil interface to prevent salt from entering the xylem.

• Tannins: Polyphenolic compounds found in high concentrations in mangrove tissues. They act as a chemical defense against herbivory and prevent microbial decay in humid environments.

• Vivipary: A reproductive trait where the embryo (Propagule) develops without a dormant seed stage while still attached to the maternal plant.

🌊 Section 2: Ecology & Geospatial Dynamics

The environmental context and the physical landscape of the mangal ecosystem.

• Accretion: The gradual increase of land area through the trapping of terrigenous and marine sediments within the complex root architectures.

• Anaerobic/Anoxic: Conditions characterized by a total lack of free oxygen, typical of the fine-grained silts found in mangrove habitats.

• Ecotone: The functional transition zone between terrestrial and marine biomes, characterized by high biodiversity and "edge effects."

• Euhaline: Water with a high salinity level, similar to the open ocean (approximately 35 parts per thousand).

• GMW (Global Mangrove Watch): An online platform providing near real-time data on global mangrove extent and changes via remote sensing.

• Halophyte: A plant physiologically adapted to thrive in high-salinity environments that would be lethal to most other vegetation.

• LULC (Land Use and Land Cover): A classification system used in satellite mapping to track how mangrove forests are being converted to other uses, such as shrimp aquaculture.

• Mangal: The scientific term used to describe the entire forest community, including the trees, associated fauna, and microorganisms.

• Zonation: The spatial distribution of species across the intertidal gradient, determined by factors such as flooding frequency and salinity.

🛡️ Section 3: Carbon Science & Conservation

The frameworks and metrics used to protect and value mangrove forests in the global market.

• Blue Carbon: The carbon sequestered in vegetated coastal ecosystems, specifically mangroves, seagrasses, and salt marshes.

• CBEMR (Community-Based Ecological Mangrove Restoration): A management framework that involves local communities in restoring natural Hydrology rather than simply planting monocultures.

• Ecosystem Services: The suite of benefits provided by mangroves, including coastal protection, fisheries support, and carbon storage.

• MPA (Marine Protected Area): A defined geographical space managed for long-term nature conservation; many "mangals" are core components of MPAs.

• NBS (Nature-based Solutions): Actions to protect, sustainably manage, and restore ecosystems that address societal challenges like climate change effectively.

• Peat: Soil composed of organic matter that is inhibited from decaying by anaerobic conditions. Mangrove peat can store centuries of carbon.

• REDD+ (Reducing Emissions from Deforestation and Forest Degradation): A framework under the UNFCCC that creates financial incentives for the carbon stored in forests.

• Tidal Flushing: The movement of water in and out of the forest with the tides, which is the most critical factor for maintaining healthy soil chemistry.