01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-07-0093 |
| Title of Abstract | Seascape connectivity has low influence on seagrass blue carbon in tropical oligotrophic islands |
| Authors | Amrit Kumar Mishra*, Syed Hilal Farooq |
| Organisation | IIT Bhubaneswar |
| Address | Udayapur Jajpur, Odisha, India Pincode: 755006 E-mail: amritkumarmishra@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Seagrass meadows are important blue carbon sinks, yet significant knowledge gaps exist in understanding the role of seascape connectivity in influencing carbon (C) and nitrogen (N) stocks. This study addressed this existing knowledge gap, by quantifying the sediment and seagrass (Thalassia hemprichii) biomass C and N stocks, and utilized stable isotope mixed modelling to assess the contribution of various sources to the sediment C pool in mixed (with other seagrass) and connected (with mangroves) meadows in the Andaman and Nicobar Islands, India. We found that mixed meadows sediment contained 3.7-fold higher total N, and enriched δ13C and δ15N values compared to connected meadows. Contrastingly, the sediment in connected meadows exhibited higher organic matter, total C, and more depleted δ13C and δ15N. Surficial sediment C stocks (3.50 ±1.78 Mg C ha-1) were higher in connected meadows, while N stocks (1.21 ± 0.71 Mg N ha-1) were higher in mixed meadows. Higher N availability led to higher density and biomass N stocks in mixed meadows. Stable isotope modelling indicated that the average contribution of T. hemprichii biomass was highest (0.68-0.69%) to the sediment C pool, followed by other seagrass biomass (0.4-0.7%) or mangrove biomass (0.10-0.14%) in mixed and connected meadows respectively. This study highlights that the influence of seascape connectivity for cross habitat subsidies of C and organic matter is lower in intertidal oligotrophic island ecosystems of the Indian Ocean region. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Blue Carbon, Blue Nitrogen, Stable Isotopes, mangroves, Thalassia hemprichii, Halophila beccarii |
| For Awards | no |