Plastic waste has been detected at a depth of about 2,000 metres in the Bay of Bengal, a discovery that scientists have described as deeply alarming and emblematic of the scale of marine pollution worldwide.

The finding was revealed during the submission of a comprehensive survey and research report on marine fisheries and ecosystems, conducted by the research vessel RV Dr Fridtjof Nansen, to the chief adviser.

A meeting to discuss the findings was held on Tuesday at the State Guest House Jamuna.

Speaking at the meeting, Professor Sayedur Rahman Chowdhury of the Institute of Marine Sciences at Chittagong University said the presence of plastic at such depths showed that pollution has penetrated even the most remote parts of the ocean.

He also warned of growing ecological imbalance, noting an excessive increase in jellyfish populations in Bangladesh’s deep sea, which he attributed largely to overfishing.

The month-long survey, conducted between August 21 and September 21 last year, involved 25 scientists from eight countries, including 13 from Bangladesh.

According to Professor Chowdhury, the research identified 65 previously unrecorded aquatic species.

However, when compared with a similar study conducted in 2018, the data show a worrying decline in large fish in deep-sea areas and an even sharper decrease in fish stocks in shallow waters.

The report highlighted the impact of industrial fishing practices.

Around 270 to 280 large trawlers are currently operating in deep waters, with about 70 using sonar-based targeted fishing, an aggressive method that maximizes catches of large fish.

While this benefits deep-sea operators, it has led to losses for small-scale fishers in coastal and shallow waters.

Fisheries and Livestock Adviser Farida Akhtar warned that if such practices continue unchecked, the Bay of Bengal could be stripped of its fish stocks.

“If targeted fishing is done in this way, there is a risk that the Bay of Bengal will become empty,” she said, adding that the government would take a decision on the future of sonar fishing.

From ocean to womb

Beyond fisheries, the discovery of plastic at extreme depths places the Bay of Bengal within a grim global pattern.

Scientific research over the past decade has documented plastic pollution in virtually every corner of the planet.

Studies published in journals such as Science and Nature have reported microplastics in the Mariana Trench, the deepest part of the world’s oceans.

A 2019 Nature Geoscience study found microplastics embedded in snow and ice samples from the Himalayas, showing that airborne plastic particles travel thousands of kilometres from their sources.

Plastic has also entered the human body.

Research published in Environment International and Science of the Total Environment has detected microplastics in human blood, lungs and placental tissue.

A landmark 2020 study by researchers at Vrije Universiteit Amsterdam confirmed microplastics in human placentas, raising concerns that plastic particles can cross biological barriers and reach the mother’s womb.

Threat to biodiversity

Environmental scientists warn that the ecological consequences are profound.

Marine animals ingest plastic directly or indirectly through the food chain, leading to injury, starvation and death.

Coral reefs, fish nurseries and seabed ecosystems are increasingly contaminated, threatening biodiversity and food security.

For humans, the long-term health effects of chronic exposure to microplastics are still being studied, but early research points to potential links with inflammation, hormonal disruption and other systemic risks.

At the Jamuna meeting, Chief Adviser Muhammad Yunus underscored the importance of science-led policy.

“Our country has an equivalent area in water as its land area, but we have not been able to utilize these resources properly,” he said.

He emphasized the need for stronger research, data collection and international collaboration to understand marine resources and protect them sustainably.

Officials also noted that the United Kingdom’s Royal Navy survey vessel HMS Enterprise is in the process of being handed over to the Bangladesh Navy, which will enhance the country’s capacity to collect seabed and oceanographic data.

The chief adviser called for coordinated joint research with countries such as Japan, Indonesia and the Maldives.

The plastic found deep beneath the Bay of Bengal is more than a local warning.

It is a stark reminder that plastic pollution has become a truly global crisis, reaching from the highest mountains to the deepest oceans and even into the earliest stages of human life, posing urgent questions about environmental stewardship, public health and the sustainability of future generations.