A new study finds severe heavy metal pollution in southeastern Bangladesh’s coastal waters, with cadmium posing high ecological risks to fisheries, marine biodiversity, and communities dependent on coastal resources.
A recent study has revealed alarming levels of heavy metal pollution in southeastern Bangladesh’s coastal regions, posing serious risks to fisheries, marine biodiversity and public health.
Research conducted by Professor Dr. Mohammed Ashraful Azam Khan and Research Assistant Kazi Nusrat Jahan Ouishi from the Department of Fisheries at Chittagong University identified the Bakkhali River and Moheshkhali Channel as major pollution hotspots. Their findings were published on November 30, 2025 in the international journal Science of the Total Environment. Field research was carried out from May 2024 to April 2025.
The study analyzed sediments from key coastal areas including the Matamuhuri River, Bakkhali River, Moheshkhali Channel, Naf River and Saint Martin’s Island using ICP-MS (Inductively Coupled Plasma Mass Spectrometry) technology to measure cadmium, copper, chromium, nickel, lead and other heavy metals.
Results showed that cadmium is the most critical pollutant, with potential ecological risk values of 331.91 percent in the Bakkhali River and 295.43 percent in the Moheshkhali Channel, indicating a very high ecological risk. In comparison, the Naf River and Saint Martin’s Island recorded lower contamination levels. Pollution Load Index values exceeded 2 in the hotspots, highlighting significant environmental stress.
The researchers attributed the contamination mainly to untreated industrial waste, urban sewage, shipbreaking activities, port operations and agricultural runoff. These pollutants accumulate in sediments and gradually enter the aquatic food chain through plankton and small organisms, eventually affecting fish and shrimp. Consequences include reduced reproduction, stunted growth, weakened immunity and declining fish populations, threatening both biodiversity and livelihoods.
“The growing presence of toxic metals in coastal regions poses a major threat to fisheries, marine biodiversity and human health in Bangladesh,” said Professor Dr. Mohammed Ashraful Azam Khan. “To ensure sustainable fisheries and a healthy coastal environment, it is essential to strengthen policies, enforce strict regulations and enhance science based environmental monitoring without delay.”
Research Assistant Kazi Nusrat Jahan Ouishi emphasized that the study aims to identify pollution hotspots, possible contamination sources and ecological risks. She said the findings will help protect coastal ecosystems, fisheries and marine biodiversity while supporting effective environmental management and pollution control.
Experts have urged declaring the Bakkhali River and Moheshkhali Channel as priority pollution hotspots along with implementing effective waste treatment facilities, stricter control of shipbreaking operations and community awareness initiatives.
Professor Mohammad Mamun Chowdhury, Chairman of the Department of Fisheries at Dhaka University, described the research as a critical step toward protecting Bangladesh’s coastal ecological balance. He highlighted that rising cadmium levels could further intensify risks for both the environment and public health.
The study also supports several United Nations Sustainable Development Goals including Clean Water and Sanitation (SDG 6), Climate Action (SDG 13), Life Below Water (SDG 14) and Life on Land (SDG 15), reinforcing global calls for urgent action against coastal pollution.
