In the wake of rapid decline in the gharial population, an initiative has been taken to exchange captive gharials among Bangladesh's zoos, with the aim of increasing numbers of the critically endangered freshwater reptile.
"There are a few captive gharials in the country's zoos, but there are no pairs of the species. That's why they're unable to breed," said ABM Sarowar Alam, principal gharial investigator of the International Union for Conservation of Nature (IUCN) Bangladesh, as quoted by UNB.
With support from the Bangladesh Forest Department, a male gharial from the National Zoo in Dhaka will be released in Rajshahi Zoo for the first time in Bangladesh on August 13, 2017, under a gharial exchange programme as there is no male Gharial there, Sarowar said.
In 2016, IUCN Bangladesh and the Bangladesh Forest Department jointly conducted a survey at Bangladesh National Zoo, Rajshahi Zoo, Rangpur Zoo and Bangabandhu Safari Park in Gazipur to ascertain the number and condition of captive gharials in the country.
The survey found that four adult males rescued from fishermen's nets between 1983 and 1997 are currently at the National Zoo and are in healthy condition, but there are no female gharials or any breeding facility.
Three adult females were found in Rajshahi Zoo. The gharial enclosure at the zoo is a circular one, with a small island in the centre. The lack of a gentle slope makes it difficult for the gharials to reach the island to bask.
Furthermore, four adult females of the species are kept in Rangpur Zoo, in an enclosure that is comparatively smaller than that of other zoos. The facilities for basking and nesting of gharials in the zoo were poor.
According to the survey, only one juvenile male of 115 cm was found in Bangabandhu Safari Park, Gazipur. The husbandry condition in the Safari park seemed to be very poor, and the gharial was kept in a small pond with more than a thousand freshwater turtles.
Sarowar Alam said the gharials would be exchanged between the National Zoo, Rajshahi Zoo, Rangpur Zoo and Bangabandhu Safari Park, so that they can make their pairs and facilitate breeding.
"All the zoo authorities have agreed to do so. And we've already prepared a breeding ground of gharials in Rajshahi Zoo," he said.
According to IUCN, there are only 200 Gharials in the wild across the world. It was declared a critically endangered species in Bangladesh in 2015.
"We don't find any breeding pairs of gharial in nature in the country, but five to 10 juveniles are found in the Padma and Jamuna rivers every year, after they get caught in fishermen's nets," Sarowar said.
The gharial investigator said that if the Gharial exchange programme was successful, the engendered freshwater reptile would be released in some select gharial hotspots of the Padma and Jamuna rivers to increase its population.
Gharial (Gavialis gangeticus) is a unique crocodilian species characterised by its long and slender snout.
According to experts, gharials mostly live in large-bodied, deep and fast-flowing rivers, and primarily live on eating fish. They help distribute nutrients from the bottom of the riverbed to the surface of the water while balancing fish populations, helping maintain aquatic ecosystems.