Temporal Change of Seagrass Meadows: Estimating Species Composition, Coverage and Carbon Stock Trends Over 16 Years in NIOF Studied Area, Hurghada, Egypt

Essa, Basma; Geneid, Yasser

doi:10.21608/ejabf.2025.419983

Temporal Change of Seagrass Meadows: Estimating Species Composition, Coverage and Carbon Stock Trends Over 16 Years in NIOF Studied Area, Hurghada, Egypt

Authors

10.21608/ejabf.2025.419983

Abstract

Seagrass ecosystems are essential coastal habitats, providing refuge for marine biodiversity and acting as significant carbon sinks. This study examined the temporal dynamics of seagrass coverage, species composition, and carbon stock at the NIOF station in Hurghada, Egypt, from 2007 to 2023, integrating field surveys with remote sensing. Field assessments quantified shoot density, biomass, and carbon stock per ground area (C_AGA) with historical records data contextualized observed trends in species composition. Five seagrass species were identified, including the dominant Halophila stipulacea, Halophila ovalis, Halodule uninervis, Thalassodendron ciliatum, and the newly recorded Thalassia hemprichii. H. uninervis exhibited the highest shoot density (808 shoots/m²) and carbon stock (C_AGA: 129.12g/ m²), underscoring its pivotal role in carbon sequestration. Seagrass coverage declined from 160.91 ha (59.8%) in 2007 to 115.16 ha (42.8%) in 2014, marking a 28.43% reduction. However, subsequent recovery was evident, reaching 171.13 ha (63.6%) in 2019 and 175.97 ha (65.4%) in 2023, indicative of successful conservation or improving environmental conditions. Concurrently, carbon stock increased from 203.57 to 222.63 tons. These findings emphasize the ecological significance of seagrass meadows in climate change mitigation and advocate for strategic conservation, restoration, and policy interventions to enhance ecosystem resilience, biodiversity, and long-term carbon sequestration.

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