The mother fish has laid eggs in the Halda River, the only natural fish breeding ground in South Asia. Due to the effect of cyclone Yaas, excess salt water entered Halda and there is no rain with more thunderstorms.
According to the Halda River Research Laboratory of Chattogram University, 6500 kg of eggs have been collected this year so far, which is at least four times less than last year. However, the amount of eggs collected has not been officially announced.
Chattogram District Fisheries Officer Farhana Lovely said the mother fish has laid far fewer eggs this year. The weather was not favorable, especially with no rain. Then due to cyclone Yaas saline water entered the Halda river which is harmful to the river. However, we are hopeful that the rain and the downhill water will actually cause the mother fish to lay eggs in Halda again this year.
Some fish released sample eggs after 12pm last Tuesday night. The carp started laying eggs after 1pm on last Wednesday night. From that time onwards, collectors started collecting fish eggs from Halda river with about 350 boats in Hathazari and Raozan sections of the river. At the end of egg collection, the process of growing fish fries from the eggs is now underway.
According to relevant sources, a record amount of 25,536 kg of eggs were found in Halda river in 2020 whereas, the number in 2019 was about 10 thousand kg. In 2018, the locals collected 22,680 kg of eggs. Earlier only 1,680 kg eggs were collected in 1027, 735 kg (sample eggs) in 2016, 2,800 kg in 2015 and 16,500 kg in 2014.
Professor Md. Manjurul Kibria, Halda Researcher and Coordinator of Halda River Research Laboratory, University of Chittagong, said that in the last 21 years, maximum efforts have been made to protect the environment, environment and mother fish of Halda. Despite such success, two environmental parameters reverse all calculations. The expected result of Rui fish eggs in Halda did not come.
He said that April to June is the breeding season for the Rui fish in the Halda River. During these three months, when there is heavy rain on the date of new moon or full moon of every month, the fish lays its eggs in the river. But this time, two months have passed since April-May, but the expected upstream of the Haldar River has not. As a result, the environment was not conducive for the release of fish eggs in the river as the hill slopes did not come.
On the other hand, the fourth full moon of May was 23-29. If there is a small amount of rain at this time, the fish is ready to lay eggs due to the maturation of the gonads. But due to the cyclone Yas, the sea became rough. The water level rises. At the same time, as Halda is a tidal river, the water level rises a lot during high tide. The intrusion of saline water into the sea occurs with tidal water, which was many times higher than normal levels?
He added that environmental barriers hampered the creation of a conductive environment for fish breeding in the Halda River. But due to the maturation of the fish gonads the slightly favorable environment is forced to lay eggs.
As a result, despite the location of many fish in the Halda River and being free from pollution, the Rui fish did not spawn as expected.