Indigenous fish species, particularly the small ones, are on the verge of extinction due to various reasons including frequent and indiscriminate use of harmful pesticides and chemical fertilizers in agricultural land, water-bodies and wetland, throughout the northern region. Apart from this, fisheries scientists and specialists said, breeding and grazing fields of the fish species have drastically been reduced due to siltation in the big rivers and their tributaries, water-bodies, floodplains and other wetlands side by side with promotion of modern fish culture in closed water- bodies. Various organizations, including the Zoology Department of Rajshahi University and the Fisheries and Aquaculture Department, conducted extensive researches that found 12 major causes for the ever-decreasing fishery resources in the region, particularly in the major rivers.
Quoting the research findings, some investigators opined that around 65 native fish species have become rare and at least 10 species vanished in the region.
Prof Dr Altaf Hossain of Zoology Department of RU told BSS that the sharp declining of spawning ground and natural seed production of fishes in most areas of the mighty Padma River has been facing an endangered condition due to withdrawal of its water from the upstream point.
Prof Hossain, who is a pioneer researcher in this field, highlighted various positive aspects of the open water-bodies in conserving the native fish species and said the open water-bodies are important not only for their fish production but also for generating employment.In addition to nutritional aspects, the open water fisheries have been contributing a lot to maintain natural ecosystem and wetland habitats along with an aquatic biodiversity, Prof Altaf added.
With excessive and indiscriminate promotion of modern technologies in both agriculture and fish culture, the grazing and breeding grounds of the native fishes are gradually declining. They viewed that frequent and indiscriminate use of pesticides and chemical fertilizers in agricultural land have directly or indirectly been destroying the open and culture water fishery resources and fish food organisms of the wetland and floodplains.
Due to extensive intervention, the habitat degradation is also affecting productivity of the water-bodies and the prevailing disturbances are significant detrimental to the native fish species and their population.
Apart from this, they said, over-fishing along with injudicious and destructive fishing practice resulting in the depletion of fishery resources and is, no doubt, dangerous for successive elimination of fish stock.
Experts, however, said the open water fishery resources in the region are being neglected for long in terms of investment and general attention to the sector.
To protect the fishery resources of the Padma River along with other water-bodies and floodplains from continuous degradation along with protecting the native fish species from their endangering situation, a sound management for rational utilization of the fisheries should be taken immediately, specialists opined. Abnormal low groundwater level has created alarm in irrigation
Meanwhile, Executive Director of Barind Multipurpose Development Authority Abdul Mannan told BSS that there are huge small rivers, canals and beels in the region which now become green paddy fields during every dry season due to massive siltation.
The huge waterbodies could be the effective means of large- scale fish farming side by side with protecting the endangered fish species if the water bodies could be transformed into water- reservoir after proper excavation and re-excavation.
Not only that, huge barren lands of the high barind tract could be brought under various crop farming fields including paddy using the conserved surface water round the year, by which, Abdul Mannan opined that the dependence on groundwater for the irrigation purposes could be lessened.