Haor dams save crops, but push fishes to extinction

Dams built in the Sunamganj Haors every year to save crops are hurting the breeding of fishes, pushing many species to extinction.

Other than the dams, which hinder the movement of fishes, excessive use of pesticides and random catching of fry are causing many fish species to go extinct.  

In the current season, 532.39km long dams were built at a cost of Tk124 crore in Sunamganj, according to officials.  

According to Professor Mrityunjoy Kundu, head of Aquatic Resource Management department at Sylhet Agricultural University (SAU), unplanned building of dams is the main reason behind the decrease in the number of fishes across haor areas.

A recent visit to the Tahirpur market, which is close to one of the largest haor in the country – Tanguar haor, revealed that most sellers are selling farmed fishes, including Pangash, Telapia, Pabda and Koi.

Due to heavy downpour and heavy rains in March every year, floods occur in the haor area and the paddy crops go under water. Crop protection dams are constructed so that the flood water does not enter the haor and damage the paddy.

"These dams, built to protect paddy, prevent fishes from breeding. Besides, the fishes are not able to move around in the water. That is why the volume of fish in the haor is decreasing," said Sarwar Hossain, fisheries officer of Tahirpur.

"Another reason is excessive use of pesticides, which hinders natural breeding," he added.

SAU Fish Biology and Genetic Department Head Dr Nirmol Chandra Roy said, "We should focus on both the paddy and fishes.

According to district fisheries office data, a total of 90,130.25 tonnes of fishes came from different water bodies of Sunamganj – some 34,134.07 tonnes came from the haors, from beels 28,624.39 tonnes and 4,544.45 tonnes from rivers.

Many species going extinct

According to data from the Sylhet fisheries office, even twelve years ago some 107 species of fishes were available but over the years many species have gone extinct. A recent survey has found that 32 of 107 species are already extinct.

The survey has placed fishes under three categories – Vulnerable, Endangered and Critically Endangered.

Among the Critically Endangered species of fishes are Tatkini, Gharua, Baghair, Rita, Rani, Pangash, Bamosh, Naftani, Chital, Ekthuti and Chaka.

Endangered species include Bacha, Chepchela, Dhela, Bamboo Leaf, Kunche, Napte Koi, Batasia Tengra, Foli and Gujiaayr.

And the Vulnerable species include Gulsha, Gonia, Darkina, Aayr, Pabda, Borobaim, Gajar, Tarabaim, Titputi, Nama Chanda and Kalibaush.