Seagrass Habitat Monitoring
Why monitor Naifaru's
seagrass habitats?
In 2025, we launched our seagrass monitoring project, aiming to monitor and therefore protect Naifaru's seagrass beds.
Seagrass faces many threats around the world, especially in tropical regions; such as heat strain from climate change, decreases in water quality, increase in algae presence preventing photosynthesis, and scarring from boat hulls and anchors.
Additionally, over 50% of resort islands in the Maldives remove their seagrass meadows for the aesthetics.
By monitoring the health of our local meadows, we can understand the local and national threats that are affecting seagrass health.
By utilising Maldives Resilient Reefs' standardised national methodology, we can collect reliable and important data regarding the health status and importance of our seagrass beds around our beloved island.
Sending this data to Maldives Reslient Reefs allows them to collate a nationwide database on seagrass health, which can aid in implementing protection and restoration measures here in the Maldives.
Three sites have been chosen to represent Naifaru: one directly opposite our centre, one aligned with our partner guesthouse OneTheIsland, and the other on the north-west of our island near a waste burning site. Each site has been chosen due to different threat levels and impacts.
By utilising equipment such as quadrats, rulers and underwater slates, we collect the data which identifies seagrass health status: percentage cover, canopy height, algae/epiphyte levels and species composition.
Seagrass Species Identification
How do we identify different seagrass species in the Maldives?
Pacific turtle-grass
Thalassia hemprichii
Ribbon-like, curved leaves 10-40cm long. Leaf tip is rounded, and slightly serrated. Short black tannin cells, 1-2mm long, in leaf blade. Thick rhizome with scats between shoots.
Sickle-leaved grass
Thalassodendron ciliatum
Erect stem up to 65cm long bearing leaf cluster. Rhizome tough and woody. ribbon-like, sickle-shaped leaves with ligule. Round, serrated leaf tip. Often found attached to rock or coral substrate.
Noodle seagrass
Syringodium isoetifoilum
Narrow spaghetti-like leaves. Cylindrical in cross section, 1-2mm diameter. Leaves contain air cavitiers. Leaf tip tapers to a point. Leaves 7-30cm long.
Ribbon seagrass
Cymodocea rotundata
Rounded leaf tip. Narrow leaf blade (2-4mm wide). Leaves 7-15cm long. 9-15 longitudinal veins. Well developed leaf sheath.
Serrated ribbon seagrass
Cymodocea serrulata
Serrated leaf tip. Wide lead blade (5-9mm wide). Leaves 6-15cm long, 13-17 longitudinal veins. Robust and strong rhizome.
Needle seagrass
Halodule pinifolia
Rounded leaf tip, 1 central vein. Usually pale rhizome, with clean black leaf scars.
Narrow-leaf seagrass
Halodule uninervis
Trident leaf tip, not rounded. 1 central vein. Rhizome usually pale, with small black fibres at the nodes. Narrow leaf blades 0.25-5mm wide.
Spoongrass
Halophilia ovalis
8 or more cross veins. No hairs on leaf surface, leaf margins smooth. Leaf 5-10mm long.
Caribbean seagrass
Halophilia decipiens
Small oval leaf blade 1-2.5cm long. 6-8 cross veins. Leaf hairs on both sides, found at subtidal depths.
