01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-08-0245 |
| Title of Abstract | Picoplankton in a Hypersaline Marginal Sea: First Comprehensive Assessment from Kuwaiti Waters of the Northwestern Arabian/Persian Gulf |
| Authors | Ayaz Ahmed*, Rakhesh Madhusoodhanan, Turki Al-Said, Loreta Fernandes, Amit Sarkar, Faiza Al-Yamani |
| Organisation | Kuwait Institute for Scientific Research |
| Address | KISR Kuwait, Kuwait, Kuwait Pincode: 20010 E-mail: naikayaz80@gmail.com |
| Country | Kuwait |
| Presentation | Oral |
| Abstract | Picoplankton (0.2⿿2 μm) are major contributors to primary production and carbon cycling in marine ecosystems, often dominating microbial food webs in oligotrophic and stressed environments. Despite their ecological importance, knowledge of their composition and dynamics in shallow, hypersaline systems such as the northwestern Arabian/Persian Gulf (NWAG) remains limited. This study investigated the seasonal and spatial variability of autotrophic and heterotrophic picoplankton in the NWAG from December 2020 to December 2021. Flow cytometry, based on fluorescence and particle size, combined with pigment profiling (HPLC; zeaxanthin as a marker), revealed distinct spatio-temporal gradients. Phototrophic picoplankton were dominated by Synechococcus spp., with picoeukaryotes forming the second most abundant group. Synechococcus biomass reached up to 88 µg C l⁻¹, particularly at northern coastal stations characterized by elevated salinity and nutrient fluxes, underscoring their ability to thrive under extreme environmental conditions. In contrast, picoeukaryotes exhibited pronounced seasonal peaks during winter and spring. Heterotrophic picoplankton biomass was elevated in coastal waters enriched in dissolved organic matter, highlighting their role in organic carbon processing. The autotrophic⿿heterotrophic assemblage exhibited clear seasonal and spatial gradients from coastal to offshore waters and across summer⿿winter seasons. These patterns are consistent with findings from other marginal and oligotrophic seas, where Synechococcus dominates under nutrient limitation and thermal stress, while picoeukaryotes contribute significantly to seasonal productivity pulses. The persistence of high Synechococcus biomass in the NWAG further emphasizes the resilience of these forms to salinity and temperature extremes. These findings establish a baseline for understanding microbial dynamics in hypersaline marginal seas and stress the need for long-term observations to anticipate shifts in ecosystem functioning under future climatic and anthropogenic change. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Microbial food web, Synechococcus, Picoeukaryotes, Flow cytometry, Carbon cycling, Environmental gradients, Seasonal variability, Anthropogenic pressures, Marginal seas |
| For Awards | no |