Freshwater Fishes: 39 endangered species return

Amid a rapidly declining fish production from inland open waters is a piece of good news that Bangladesh has made a great stride in reviving 39 endangered freshwater species.

Many of the species have been massively cultivated by farmers triggering a huge production boom.

Bangladesh has emerged as the world's third-largest sweet-water fish producer, according to the latest report of the Food and Agriculture Organisation (FAO).

The report, released in 2022, said the country produced 1.25 million tonnes of freshwater fish.

In 1980, the production was 0.44 million tonnes.

Sixty-four out of 260 freshwater species of the country have so far been identified as endangered by the IUCN in its 'red list'.

But the Bangladesh authorities have said the list, prepared in 2015, needs to be revised as many of the species have come back as he cited an example of ayer.

"Bagha ayer was declared endangered but nowadays we've found a significant amount of fish available in the market," said Department of Fisheries director general (DG) Dr Khondoker Mahbubul Huq.

"We've already sought a meeting with the IUCN, but it is yet to respond," he told the FE.

About the return of endangered fishes, Anuradha Bhadra, principal scientific officer of Bangladesh Fisheries Research Institute, said they were able to revive the endangered species through artificial breeding.

Popular varieties like koi, magur, bata, shoal, pabda have been restored in the country through this process.

The Bangladesh Fisheries Research Institute (BFRI) DG has made a significant contribution to conserve the endangered fishes as it developed the breeding and culture technology of 39 endangered and indigenous fishes for conservation and nutrition supply.

As a result, the availability of endangered fishes significantly increased in the market, he added.

In the latest assessment, 64 out of 253 fish species have been found threatened, which is 25.3 per cent of the total species assessed.

According to the IUCN report, 12 species are critically endangered (CR), 28 species endangered (EN), 14 species vulnerable (VU), 66 species data deficient (DD) and the rest 146 species not threatened (NO).

This shows an estimated 18.5 per cent increase in threatened fish in the 2015 assessment over the previous assessment done in 2000.

However, there is a decrease in CR species by 25 per cent in the 2015 assessment.

But the EN and VU species showed increases by 21.4 per cent and 78.5 per cent respectively.

As fish is the second staple food after rice in Bangladesh and it supplies 60-per cent animal protein, experts felt that preserving fish species is crucial to ensure food security.

An estimated 1.2-million professional fishers in Bangladesh are involved in fishing full-time for livelihood, while another 10 million undertake subsistence fishing either for supplementing their incomes or for household consumption.

According to experts, habitat loss, pollution of water bodies and overfishing are the key reasons for depletion of natural fish resources.

"Habitat loss caused by massive siltation, infrastructure development, drying up of water bodies, dewatering, conversion of wetlands, overfishing and aquatic pollution are the major causes for fish population decline in Bangladesh," found the IUCN.

The total freshwater area is estimated to be 4,699,387 hectares, providing an extensive habitat for wide varieties of fish and other aquatic organisms.

Experts say rapid rise of human population and massive use of natural resources, agricultural and industrial activities along with deficient water management have led to growing threats for freshwater fish.

Major human-induced impacts are habitat destruction and fragmentation through blockade of migration routes, invasive alien species, overexploitation, disease, aquatic pollution, incidental mortality and climate change, they said.

Embankments for protection from tidal inundation and flood control, and irrigation have contributed greatly to the degradation of wetlands and consequently to its resources, according to fisheries experts.

High demand and high prices of fishes, coupled with high unemployment, resulted in putting increased efforts in fishing and very often these lead to over-exploitation of aquatic resources, particularly fishes.

They feel that overfishing affects both commercial species and non-targeted small species as by-catches.

Massive use of pesticide and fertiliser to boost crop production also menaces fish population as pesticides are detrimental to aquatic life forms.

About impacts of pollution, experts said effluents from dyeing, leather, chemical or paper industries are major sources for aquatic pollution here.

Similarly, municipal sewerage emptying into open waters also poses a serious threat to freshwater fishes locally, they added.

Emphasising stronger legal steps to prevent fish depletion, many feel that the Fish Conservation Act should include the threatened species for conservation.

The current fish acts need to be amended with a provision for conservation and management of the threatened species, according to the experts.

The IUCN in its recommendations said the Wildlife (Conservation and Security) Act 2012 also needs to be amended with more focus on threatened fish species.

However, the DG said the government has taken several steps to conserve sweet-water fish species.

The government in a major move is going to create a 12-kilometre sanctuary in the Jamuna, six km up from Jamuna Bridge and six km down from it.

Four more sanctuaries will be created in the country very soon-two in Moulvibazar district and two in Sherpur district.

Besides, the department is going to launch a wetland conservation project amounting to more than Tk 1,000 crore in next fiscal, he added.

There latest project ended last June.

mirmostafiz@yahoo.com