The increasing number of heavily polluting factories producing petrochemicals, cement, and leather on the edge of the Sundarbans, as well as new thermal power plants, threatens the mangrove ecosystem

Mongla port is a hive of activity. Several oceangoing vessels are anchored in the harbour and there is a steady bustle of barges hauling cargo. Defunct for a long time, a deepening of the shipping channel around the turn of the century has led to a dramatic turnaround, making Mongla one of the fastest growing ports in South Asia.

Strategically located in south-western Bangladesh, the success of Mongla is due to the frenetic industrialisation in its hinterland. Within a radius of 10 kilometres there are several cement factories, a petrochemical refinery, and many gas bottling plants - with scores more being built, among them a massive USD 21.5 million leather processing plant and the contentious Rampal thermal power plant. They are part of Bangladesh's growth story, whose GDP has been growing at a rate of over 5% annually for the past several years.

This humming industrial hub, however, carries with it an environmental cost that may be high enough to endanger the economy of the entire region. Situated as it is on the edge of the Sundarbans - a world heritage site and a biodiversity hotspot - the risk of pollution to its unique ecosystem is quite high, environmentalists fear.

Ecologically critical area

The Bangladesh government has in the recent past tried to frame rules that seek to mitigate the potential harm to the planet's largest mangrove forest, which straddles Bangladesh and India. It has stipulated that no industrial activity can take place within 10 kilometres of the Sundarbans forest reserve, which is designated at as an ecologically critical area (ECA). However, more than 150 industrial units were already approved in Satkhira, Khulna, and Bagerhat (where Mongla is located) districts before these rules came into force. And the rules will not be implemented with retrospective effect.

Bangladesh's environment ministry had issued permission to set up 186 industrial projects in the region before the ECA designation came into effect. Among them, 140 industries were given permission in Khulna, Bagerhat, and Satkhira with final clearance from the department, according to a media report. Other than these, the 21 industrial units of Mongla Export Processing Zone, 21 industrial units of Mongla Port Industrial Area, and five other industrial units near the port area also received permission, the report said.

Local authorities say they do not have any control over providing environmental clearances to these proposed factories. "The clearances are given at the central level in Dhaka (Bangladesh's capital)," Mohammed Zulfikar Ali, Mayor of Mongla Port, told thethirdpole.net. "We can only express our concern." That clearly isn't sufficient, as Bangladesh's Prime Minister, Sheikh Hasina, on a recent visit to Mongla has spoken positively about the role of the industries in the area, Ali said.

The Mongla Export Processing Zone is expected to be the main economic hub of the southern region of the country, Mohammed Habibur Rahman Khan, Executive Chairman of the Bangladesh Export Processing Zones Authority (BEPZA), said in a meeting last year. The industrial units already operating within the ECA in Mongla include four cement factories, one soybean oil refinery, one crude oil refinery, four gas bottling companies, and one cigarette factory, Mallick Anwar Hossain, director of the department of environment at Khulna, was quoted as saying in a media report.

The situation is potentially alarming since there are no effluent treatment plants in the area, according to a 2015 report prepared by PricewaterhouseCoopers (PwC). While preparing a feasibility plan to set up an economic zone in Mongla, PwC found that there is no drainage system in the area, nor is there any wastewater treatment plant. Given that many of the factories already operating in the locality are highly polluting (cement, petrochemicals etc.), it is anybody's guess how the pollution load of these units is managed and regulated.

No lessons learnt

It seems that the authorities in Bangladesh have learnt no lessons from the impact of industrialisation in the neighbouring state of West Bengal in India. Researchers have found that industrial units located on the Gangetic delta in the Haldia port-cum-industrial complex on the Hoogly River, and in the eastern metropolis of Kolkata and its outskirts, are polluting the fragile ecosystem of the Sundarbans, home to over 4.5 million people in India alone.

A 2014 study done on heavy metal pollution in the lower Gangetic mangrove ecosystem by Abhijit Mitra, Sufia Zaman and Subhrabikash Bhattacharya of Calcutta University found that organic and inorganic wastes released from industries and urban units contain substantial concentrations of heavy metals. "The deltaic lobe is unique for its wilderness, mangrove gene pool and tiger habitat," the study said. "However, due to intense industrial activities in the upstream zone, and several anthropogenic factors, the aquatic phase in the western part of the deltaic complex is exposed to pollution from domestic sewage and industrial effluents leading to serious impacts on biota."

The study found heavy metal accumulation in the muscle of tiger prawns, which are cultivated widely in and around the Sundarbans and fetch a premium price in the global market. "The low salinity and intense industrialisation in the Hooghly estuarine stretch is responsible for the high concentration of heavy metals in the shrimp muscle sampled from stations in and around the western side of Sundarbans," marine scientist Abhijit Mitra said in a report.

Through a series of studies, scientists have found increased presence of zinc, copper and lead in the body of a shellfish species known as the Indian white shrimp. Found abundantly in the water of Sundarbans, the many varieties of shrimp are important for the livelihoods of millions of people living on the fringes of the mangrove forest.

Problems compounded in Bangladesh

Unlike in India, where the raw material for the factories along the Hoogly River is transported over land, in southern Bangladesh seeing rapid industrialisation, these are carried mainly through the delta's waterways, increasing the chances of water pollution. This was evident in the 2014 oil spill in the Sela River, just a few kilometres downstream of Mongla port.

The Sela River, which runs through a sanctuary for the endangered Irrawaddy and Ganges river dolphin along the northern edge of the Sundarban East Wildlife Sanctuary, was in the global spotlight since December 9, 2014, when a wrecked tanker released some 94,000 gallons of heavy fuel into the river. In May 3, 2015, a capsized cargo vessel leaked 200 tonnes of potash fertiliser into the Bhola River, southeast of the earlier oil spill.

Although the authorities have turned more vigilant after these disasters, the potential of more such incidents cannot be ruled out, especially since Bangladesh plans to increase its marine traffic with India manifold. According to the PwC report, clinker is one of the major components of general imports at Mongla for use by the local cement plants. The report expects the traffic in coal and leather laden cargo vessels to increase in the coming years.

There is already an incessant stream of heavily laden small cargo boats crowding the Mongla port. Navigation in the Sundarbans waterways has increased 236% in the past seven years, the International Union for Conservation of Nature (IUCN) said in a December 2015 report, citing the Mongla Port Authority.

There is still scant research on the effect of industrialisation in the Sundarbans in Bangladesh. A study published in 2017 on heavy metal contamination in water, sediment and fishes in the Passur River in the Mongla port area, which studied samples collected in 2013, found no significant increase that could be attributed to human interventions.

Much water has flowed through the waterways in these five years since the data for the study was gathered, and the pace of industrialisation has only increased. It is, therefore, reasonable to expect that industrial pollution will start impacting the biodiversity of the Sundarbans in a way that could be irreversible in the near future.

Soumya Sarkar is the managing editor of indiaclimatedialogue.net.