Ilish can migrate to another country from Bangladesh

0
8

Pollution in the rivers, underwater chars, and illegal fishing in the coastal areas are some of the main reasons behind the fish migrating away Syed Zakir Hossain/Dhaka Tribune

As ilish production declines in the Padma-Meghna, Dhaka Tribune’s Bilkis Irani dives into the reasons behind the slump. This is the second of a four-part series of reports

The sudden decline of ilish production in Padma-Meghna rivers in Chandpur district has made a warning sign that the fish may migrate to other countries and disappear from Bangladesh in future.

This warning was given by ilish researchers while huge ilish production is on the rise in the south. The experts urged that immediate necessary measures be taken to protect the sanctuary of ilish so that ilish does not vanish from Bangladesh.

Trader Sadi Uddin (Dadon Bepari) said: “Ilish production will be in threat in the future if it cannot come to Padma-Meghna rivers in Chandpur as it is the main sanctuary of ilish in Bangladesh.”

Three obstacles

Experts have emphasized on three reasons which are the big obstacles which prevent ilish from coming to its sanctuary at Padma-Meghna in Chandpur. 

According to the Bangladesh Fisheries Research Institute, polluted water in the river, underwater char, and catching fish with banned fishing nets in coastal areas and other districts are the three main reasons to prevent ilish coming into the estuary of Padma-Meghna this year.

Water pollution: Researchers said polluted water expanding over the Padma and Meghna rivers from the Buriganga river wastes and chemicals which mills and factories dispose of reduces the level of oxygen and plankton, the best food for mother ilish. This will be a threat for all the fishes including ilish to survive in Padma-Meghna.

According to the Department of Environment (DoE), the level of Environmental Quality Standards (EQS) for fisheries should be 5mg/L. Though the Dissolved Oxygen (DO) of Padma river was found 6.30mg/L during wet season (May-October) in 2015, last week it was found decreased to 5.5mg/L.  

Shallow water fish like ilish cannot survive if the DO becomes too low, less than 4mg/L. Meanwhile, no fish can survive in Buriganga as the DO of Buriganga came below 2mg/L. 

According to the research from the Natural Resources Defense Council (NRDC), textile manufacturing in the country has been generating as much as 300 tons of wastewater per ton of fabric, with a host of harmful chemicals. Besides, high amounts of food waste including rotten fruits and vegetables, pollute the Buriganga which is gradually spreading into the estuary of Padma-Meghna river, as well.

Underwater char: Several vast ranges of underwater char have been found in Padma and Meghna rivers which is a big obstacle for ilish, as it moves very fast in the water.

This correspondent spent a day with the ilish researchers on the Padma-Meghna and saw the Fish Measuring Device echo sounder, which showed 52 level depth where the picture of some ilish fish was visible at the estuary of Padma-Meghna.

When the echo sounder came down to 10 level depth, no ilish were found visible through the device.

Using banned fishing nets: After visiting Noakhali, Dhaka Tribune found some fishermen were repairing a big three-part net where the traps of the net were smaller, less than four-inch, which is banned to catch fish.

They were not using the current net (current jal) but a small-sized netting technically sewed in the middle of the net, secretly so that no small fish can escape from the net. 

These big banned nets are used in Barisal, Bhola, and Barguna as well, therefore very few ilish can move forward escaping from this type of net.

Photo: Syed Zakir Hossain/Dhaka Tribune

Other threats to worry about in future

Dr Anisur Rahman, chief scientific officer of Bangladesh Fisheries Research Institute, River Centre Chandpur, has warned that because of these three obstacles ilish can migrate to another country and may totally vanish from Bangladesh. 

“Though ilish is a sea fish, it is born and grown in our Padma and Meghna rivers since the water and waves of this river is perfect for mother ilish to release eggs. Estuary of Padma-Meghna in Chandpur has enough plankton as their food as well as for them to survive,” said the eminent ilish researcher of the country.

“Ilish is the fastest fish inside the water and likes uninterrupted roaming. But now they are getting obstructions while entering the river. If they get any obstacles on their way, they change their way to another place,” he added.

Chairman of Department of Zoology at Dhaka University Prof Dr Niamul Naser said the pollution caused by the dumping of pesticides and industrial chemicals into the river also threatens the survival of the fish.

He stressed on the need to ban the extraction of ilish in the rivers as well as in the sea for a certain period of time to keep the production of ilish sustainable, since large quantities of ilish being caught by a huge number of nets in the sea and the southern areas before coming to Chandpur.

“It is really a matter of concern if fishermen do not get ilish in Chandpur area during this peak season since Chandpur is the main sanctuary of ilish. If ilish can not come here because of char and pollution this time, there is no certainty of it coming during the breeding season and releasing eggs,” he said. 

“There is no accurate data and instruction on how many ilish are being caught and how many should be caught. Long research and instructions should be there so that stocks do not run out. 

“The government also should take necessary measures for smart dredging in the river, reducing river pollution and use of banned nets in the coastal areas for the easy movement of ilish fish in the Padma-Meghna river,” the professor added.

Fisheries and Livestock Minister SM Rezaul Karim also accepted the truth and told this newspaper that because of pollution in the rivers, ilish is turning away from the Padma.

“Besides, some immoral people have been lifting sand from the river which is creating the hole inside the river and waste from mills are getting stuck inside it, which is creating big obstacles for ilish movement.

“We are planning to take necessary measures including dredging so that fishermen get ilish from their areas where they got huge ilish earlier,” he added.

Obsolete data on Department of Fisheries website

According to the last data of Department of Fisheries 31,219 tons of ilish were caught from the lower Meghna in Chandpur district during fiscal year FY2017-18. No ilish was caught from the upper Meghna and Padma rivers. 

But Chandpur district officials said, there is no individual data for river ilish. They count all ilish both from the sea and rivers of other districts together. 

According to them, a total of 48,625 tons of ilish were caught in FY2019-20 and 36,700 tons in FY2018-19.

“It is not possible to identify river ilish individually because of the shortage of manpower but we know that very few ilish come from Padma-Meghna river in Chandpur because of pollution and char,” Chandpur Fisheries official Asadul Baki said.

“It is unbelievable that fishermen of Padma-Meghna rivers in Chandpur area are not getting ilish fish. It is absolutely concerning, we will carry out a research about it. We must focus on it,” Masud Ara Momi, deputy chief, Ilish Section, Department of Fisheries, said.

The data also mentioned that 533,000 tons of ilish were produced in FY2018-19 across the country, which was 298,000 tons in FY2008-09.

After taking steps to protect jatka, a Gazette was published to protect mother ilish in 2010 and ban ilish fish catching for a certain period, which gradually improved ilish production.

(function(d, s, id) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) return;
js = d.createElement(s); js.id = id;
js.src = ‘https://connect.facebook.net/en_US/sdk.js#xfbml=1&version=v3.0&appId=403175913072993&autoLogAppEvents=1’;
fjs.parentNode.insertBefore(js, fjs);
}(document, ‘script’, ‘facebook-jssdk’));

Source link

Leave a Reply