The adverse impact of climate change has been posing a serious threat to indigenous fish species, particularly the small ones, as most of the water bodies in the region, especially in the high Barind tract, are now dying.
Fisheries scientists and specialists said the breeding and grazing fields of the fish species had been drastically reduced due to the abnormal situation, coupled with siltation in the big rivers and their tributaries, water-bodies, floodplains and other wetlands.
Dr Akhter Hossain of the fisheries and aquaculture department of Rajshahi University said the scanty rainfall and scorching heat were causing habitat degradation affecting the productivity of the water-bodies and the unusual situation was a significant detriment to the population of the native fish species.
He said over-fishing along with injudicious and destructive fishing practice resulted in the depletion of fishery resources and was, no doubt, dangerous because of the successive elimination of fish stock.
All varieties of native fish are on the decline because of a drastic fall in surface water resources. The sharp fall in production of local fish resources is also widely blamed on the indiscriminate catching of the mother fish which fall prey to the fishermen in confined water bodies.
Dr Akhter highlighted various positive aspects of open water bodies in conserving the native fish species and said open water bodies were important not only for their fish production but also for generating employment.
A sound management system for rational utilisation of the fisheries should be designed immediately to protect the fishery resources of the Padma River and with other water-bodies and floodplains from continuous degradation, and to protect the native fish species from their endangered situation.
Prof Dr Bidhan Chandra Das of the Rajshahi University zoology department said there were many small rivers, canals and beels in the region which became green paddy fields during each dry season due to massive siltation.
The huge water bodies could be effective means of large-scale fish farming and also protect the endangered fish species, if the water bodies could be transformed into water reservoirs after proper excavation and re-excavation, he said.
In addition, by using the conserved surface water round the year, many large tracts of barren land on the high Barind tract could be used to farm various crops, including paddy. Prof Bidhan Das opined that this would also lessen the dependence on groundwater for irrigation.