The current wild population of Gharials is 198 individuals, which means that the 23 that were released this year, accounts for around 1 eighth of the wild population. Furthermore, having been released into former range of the Gharial, they are unlikely to encounter other Gharials until the population is far less endangered.
Part of the reason for their decline is down to the dams and similar which have been built on the rivers, and have separated this population, so that they have been unable to breed.
The last gharial on the river that they were reintroduced to was seen in 1993.