title: Seagrass metabolism and carbon dynamics in a tropical coastal embayment.
abstract: Net ecosystem metabolism and subsequent changes in environmental variables were studied seasonally in the seagrass-dominated Palk Bay, located along the southeast coast of India. The results showed that although the water column was typically net heterotrophic, the ecosystem as a whole displayed autotrophic characteristics. The mean net community production from the seagrass meadows was 99.31 ± 45.13 mM C m-2d-1, while the P/R ratio varied between 1.49 and 1.56. Oxygen produced through in situ photosynthesis, exhibited higher dependence over dissolved CO2and available light. Apportionment of carbon stores in biomass indicated that nearly three-fourths were available belowground compared to aboveground. However, the sediment horizon accumulated nearly 40 times more carbon than live biomass. The carbon storage capacities of the sediments and seagrass biomass were comparable with the global mean for seagrass meadows. The results of this study highlight the major role of seagrass meadows in modification of seawater chemistry. Though the seagrass meadows of Palk Bay are increasingly subject to human impacts, with coupled regulatory and management efforts focused on improved water quality and habitat conservation, these key coastal ecosystems will continue to be valuable for climate change mitigation, considering their vital role in C dynamics and interactions with the overlying water column.
authors.affiliation: National Centre for Sustainable Coastal Management (NCSCM), Ministry of Environment, Forest and Climate Change (Government of India) Koodal Building, Anna University Campus, Chennai, Tamil Nadu, 600 025, India.
authors.forename: Dipnarayan
authors.initials: D
authors.lastname: Ganguly
authors.affiliation: National Centre for Sustainable Coastal Management (NCSCM), Ministry of Environment, Forest and Climate Change (Government of India) Koodal Building, Anna University Campus, Chennai, Tamil Nadu, 600 025, India.
authors.forename: Gurmeet
authors.initials: G
authors.lastname: Singh
authors.affiliation: National Centre for Sustainable Coastal Management (NCSCM), Ministry of Environment, Forest and Climate Change (Government of India) Koodal Building, Anna University Campus, Chennai, Tamil Nadu, 600 025, India.
authors.forename: Purvaja
authors.initials: P
authors.lastname: Ramachandran
authors.affiliation: National Centre for Sustainable Coastal Management (NCSCM), Ministry of Environment, Forest and Climate Change (Government of India) Koodal Building, Anna University Campus, Chennai, Tamil Nadu, 600 025, India.
authors.forename: Arumughan Paneer
authors.initials: AP
authors.lastname: Selvam
authors.affiliation: National Centre for Sustainable Coastal Management (NCSCM), Ministry of Environment, Forest and Climate Change (Government of India) Koodal Building, Anna University Campus, Chennai, Tamil Nadu, 600 025, India.
authors.forename: Kakolee
authors.initials: K
authors.lastname: Banerjee
authors.affiliation: National Centre for Sustainable Coastal Management (NCSCM), Ministry of Environment, Forest and Climate Change (Government of India) Koodal Building, Anna University Campus, Chennai, Tamil Nadu, 600 025, India. rramesh_au@yahoo.com.
authors.forename: Ramesh
authors.initials: R
authors.lastname: Ramachandran
mesh_terms: D002244:Carbon; D057231:Climate Change; D017753:Ecosystem; D006801:Humans; D007194:India; D012623:Seawater / Q000737:chemistry
chemical_list: D002244:Carbon
keywords: Aragonite saturation; Carbon uptake; NCP; Palk Bay; Seagrass meadows