Capture and storage of Carbon in seagrass beds of a vulnerable species Halophila beccarii (Asch.) at the Kadalundi Estuary, Kerala, India

Abstract

Seagrass habitats are efficient carbon sink that can bury and store organic carbon for a long time. We report here the capture of dissolved CO 2 by the ocean-turf grass, Halophila beccarii and its storage as carbon stock in the sediments extending an area of two hectares in the mudflats of Kadalundi Estuary. The organic carbon content in the seagrass sediment showed gradual increase from 0.473% during January to 0.824% during March. Organic carbon content in the sediment within the Halophila bed was 110-134% higher than that of outside the seagrass bed. The three months observation, though a short term study revealed that the mean values of blue carbon stock of Halophila beds of Kadalundi Estaury were at 2.655±0.34 Mg C/ha. The capture potential of dissolved CO 2 by the seagrass, unravelled through an experiment involving intact plants showed that the Halophila plants could utilize 21.4%-25.7% of dissolved CO 2 in light within 2 hours.

Organic carbon storage in sediments of seagrass habitats in the lagoons of Lakshadweep Archipelago, west coast of India

“…Seagrass meadows rank among the most significant organic carbon (C org ) sinks on earth (Mazarrasa et al, 2021;Serrano et al, 2018;. The carbon storage potential of seagrass meadows from Indian waters is known from the Gulf of Mannar and Palk Bay , Chilika and Pulicat Lakes (Kaladharan et al, 2021a) along the east coast and from Kadalundi Estuary (Kaladharan et al, 2021b) along the west coast. This communication is intended to bring out the blue carbon storage potential of seagrass habitats from the lagoons of Agathi, Bangaram, Kavaratti, Kalpitti, Thinnakara and Parli Islands of U.T.…”

Eutrophication decreases Halophila beccarii plant organic carbon contribution to sequestration potential

“…Halophila beccarii is a small monoecious seagrass mainly distributed throughout the tropical Indo-Pacific region (Udagedara and Dahanayaka, 2020). The blue carbon stock of H. beccarii meadows ranged from 2.655 Mg C/ha to 12 Mg C/ha (Jiang et al, 2017;Kaladharan et al, 2021). The organic carbon concentration in the sediment within the H. beccarii seagrass meadow is 110%-134% greater than nearby bare sediment (Kaladharan et al, 2021), possibly due to abundant H. beccarii plant organic carbon inputs into in situ sediment (Premarathne et al, 2021).…”

“…The blue carbon stock of H. beccarii meadows ranged from 2.655 Mg C/ha to 12 Mg C/ha (Jiang et al, 2017;Kaladharan et al, 2021). The organic carbon concentration in the sediment within the H. beccarii seagrass meadow is 110%-134% greater than nearby bare sediment (Kaladharan et al, 2021), possibly due to abundant H. beccarii plant organic carbon inputs into in situ sediment (Premarathne et al, 2021). H. beccarii is widely distributed in tropical and subtropical regions of China, which are at a risk of further nutrient loading pressure due to intense human activities (urban runoffs, fishing, dredging) (Jiang et al, 2017;Jiang et al, 2020).…”