Croplands shrink amid rising salinity in Bagerhat

The coastal district of Bagerhat has undergone a sweeping transformation over the past decade. The glistening wetlands that once stretched as golden paddy fields are now widely used for shrimp farming due to a sharp rise in water salinity.

In Rampal, Mongla, Morrelganj and parts of Bagerhat Sadar, vast stretches of cropland once used for paddy cultivation have been converted into aquaculture ponds.

While the boom in shrimp farming has brought prosperity for large leaseholders and investors through lucrative export markets, most small farmers and day labourers have faced displacement and rising debts, as their farmlands can no longer support crops because of high salinity.

Mizanur Rahaman, 39, in Morrelganj upazila, said he now cultivates paddy on 2.5 bighas of land, while the remaining 5 bighas have been turned into shrimp ponds.

Kamrul Dihider, 35, of the same upazila, said he stopped paddy cultivation altogether and converted his 5-bigha land into a shrimp enclosure.

"As saline water crept inland from neighbouring waterbodies, thousands of local paddy farmers saw their harvests wither. Over the years, many have been forced to lease out their land to shrimp entrepreneurs for a fraction of its former value," said a farmer of Taligati village.

A 2024 survey by the Soil Resource Development Institute in Khulna, with data from the Department of Agricultural Extension in Bagerhat, found that salinity levels in parts of the district nearly doubled over the last decade.

The Pashur, Daratana, Panguchi and Ghashiakhali rivers now register alarming salinity levels of 15–30 decisiemens per metre during the dry months of March and April, several times higher than what paddy or most vegetables can tolerate.

In 2020, Bagerhat's total agricultural area was 1,84,841 hectares. By 2024, total farmland had declined to 1,60,861 hectares.

Noor Alam Sheikh, Khulna divisional coordinator of Dhoritri Rokhhay Amra, said, "Expansion of shrimp farming, introduced in the 1980s, has turned into a catastrophe for the agricultural environment and public health. While shrimp exports generate only Tk 3,000–4,000 crore in foreign currency, the resulting damage -- the social cost to agriculture, the environment and public health -- is estimated to be as high as Tk 50,000 crore."

"Given this imbalance, shrimp farming should either be halted or strictly managed under a proper plan," he said.

According to fisheries department data, 52,551 hectares of land in Bagerhat are now under Bagda shrimp farming, yielding 20,940 tonnes this season. Another 19,773.3 hectares are used for Galda prawn farming, yielding 19,716.3 tonnes.

Meanwhile, river salinity in parts of Bagerhat, including Mongla and Rampal, now averages around 5–7 parts per thousand, reflecting the intrusion of saline water inland.

Md Motahar Hossain, deputy director of the Department of Agricultural Extension in Bagerhat, said salinity intrusion now begins as early as November, rather than January, severely affecting crops by March–April.

He said officials are promoting salt-tolerant crop varieties and converting single-crop fields to double-cropping systems to help farmers maintain output despite shrinking farmland.

Raj Kumar Biswas, district fisheries officer in Bagerhat, said, "It is crucial to limit salinity and improve water management. Officials are working on measures to control the problem."-----------------------------