Publications & Papers

This study investigated the spatial distribution, abundance, and polymer composition of microplastics in intertidal and subtidal sediments at 12 sites along the Chittagong coast of the Bay of Bengal. Samples were collected across two seasons and analysed using FTIR spectroscopy. Microplastic abundance ranged from 420 to 1,340 particles per kg dry weight. Fibres were the dominant morphotype (62%), and polyethylene and polypropylene were the most prevalent polymers. A Pollution Load Index was calculated for all sites, with 8 classified as heavily polluted. Results suggest significant inputs from fishing activities, urban runoff, and industrial effluent.

Marine spatial planning (MSP) is an essential tool for coordinating human activities in coastal and marine environments. This study developed the first comprehensive GIS-based MSP framework for Bangladesh's 200-nautical-mile Exclusive Economic Zone. Eighteen spatial data layers were integrated covering fisheries, shipping, biodiversity, energy, and conservation. Six priority conservation zones and four offshore wind energy areas were identified. The framework was submitted to the Bangladesh Department of Fisheries as a policy reference document and contributed to the national Blue Economy Action Plan consultation.

This study analysed land use and land cover (LULC) change across the coastal belt of Bangladesh over a 20-year period (2000–2020) using Landsat 5, 7, and 8 imagery. Supervised maximum likelihood classification was applied, achieving an overall accuracy of 92.4% (Kappa: 0.89). Results revealed an 18.3% decline in mangrove cover and a 41% expansion in shrimp aquaculture. Urban areas expanded by 23.7%. Transition matrix analysis identified mangrove-to-aquaculture conversion as the dominant change trajectory. The study provides critical baseline data for conservation planning in the Bangladesh coastal belt.

Seasonal phytoplankton community structure was investigated in the Karnaphuli and Meghna estuaries across four sampling campaigns. A total of 87 phytoplankton taxa were identified, with Bacillariophyceae dominating in all seasons (52–68% of total assemblage). Shannon-Wiener diversity index ranged from 1.8 to 3.2, with lowest values recorded during the monsoon season. Significant positive correlations were observed between salinity and species richness (r=0.76, p<0.01). The study provides the first comprehensive seasonal baseline for phytoplankton communities in the Karnaphuli Estuary.

The oxygen minimum zone (OMZ) of the northern Bay of Bengal is one of the most intense in the global ocean, yet its seasonal dynamics remain poorly characterised. This study presents dissolved oxygen profiles, nitrate, nitrite, and phosphate data from 40 stations sampled across four seasonal cruises (2021–2022). The OMZ core (DO <2 mg/L) was mapped between 150–800m depth. Strong seasonal nitrogen cycling driven by monsoon-induced upwelling was documented. Results contribute to the IPCC AR6 regional biogeochemical assessment and provide baseline data for climate sensitivity modelling of Indian Ocean OMZs.

Heavy metal concentrations (Pb, Cd, As, Cr, Hg) were determined in 180 composite soil samples collected from 30 agricultural sites adjacent to industrial areas in Gazipur, Narayanganj, and Chittagong EPZ. Geo-accumulation index, contamination factor, and ecological risk indices were calculated. Cadmium and lead concentrations exceeded WHO guidelines at 73% and 61% of sites respectively. Narayanganj showed the highest contamination load. High ecological risk classification was assigned to 18 of 30 sites. Findings were submitted to the Bangladesh Department of Environment to support industrial buffer zone policy development.

This study used Digital Shoreline Analysis System (DSAS) and multi-temporal Landsat imagery to quantify shoreline change rates along 240 km of the Bay of Bengal coast from 1990 to 2020. Net Shoreline Movement ranged from -85m to +120m across study transects. Erosion dominated in exposed sections (mean -2.8 m/yr), while accretion occurred in sheltered bays. Results highlight the need for dynamic coastal zone management policies accounting for climate-driven shoreline variability.