Gharials have bred for the first time in captivity in the world at Nandankanan Zoological Park in 1980. The breeding pool of Gharials was completed and started functioning in the February 1976 with introduction of three (One male & 2 female) Gharials. The pool covers an area of 1040 Sqm and constructed in oval shape with max-depth of 9.15 m. It measures 60mt at the longest part, 30mt at the widest part. It holds 2.70 million liters of water. Three hatchlings caught from river Mahanadi and one female obtained from Trivandrum were introduced during March, 1979. During January, 1980 one adult male crocodile was obtained from Frankfurt Zoo and released to the pool. During breeding season, courtship and mating was observed and first clutch of 25 eggs were laid in March, 1980. Hatching of crocodile eggs both in artificial hatchery and naturally inside the enclosure was successful in the same year and was continued in subsequent years. As a result of which the stock of Gharials in the pool was increased to 206 during the year 1985. It was decided by the Zoo administration to dispose the crocodile either by releasing them in nature or sending them to other Zoos under animal exchange programme.

During the year 1986-87, 81 Gharials were first released in Mahanadi river system. Releasing the Gharials in nature was continued in subsequent years and in total 578 Gharials were released in nature and 64 were transferred/ exchanged to other centers/ Zoos till date.

In the year 2015 the last adult male Gharial of Nandankanan has died. It was decided to find out the nest in the sand banks of the pool and incubated the available eggs artificially in sand cube with facility to monitor and regulate temperature and humidity. The effort was made to get Gharial hatchlings out of which 71 are surviving today with good health.

Species Recovery of Gharial in River Mahanadi

Introduction

Odisha is the only state of India with all three species of crocodilian; Gharial (Gavialis gangeticus), Mugger (Crocodylus palustris) and Saltwater crocodile (Crocodylus porosus). Mahanadi, one of India's major rivers is home to the only population of gharials in Odisha and the southernmost distribution limit

Project details

Considering the dwindling population of gharials in the river Mahanadi, the Forest Department of Odisha initiated a project “Species Recovery of Gharial in River Mahanadi” in 2019 to rehabilitate gharials in the river Mahanadi following strict monitoring protocols. Under the project, it was proposed to release 35 gharials (12M:23F) bred and reared at the Nandankanan Zoological Park, Bhubaneswar into the river Mahanadi in a phase-wise manner to build a sustainable population in the wild.

Key Steps:
Pre-Release Surveys: Prior to the Gharial releases, comprehensive pre-release surveys were conducted to identify suitable release sites along the river
Transmitter Tagging: Between 2019 and 2022, a total of 19 gharials consisting of 7 male and 12 female gharials tagged with radio and satellite transmitters were released in different batches in the river measuring 1.5m to 3.85m in length and aged between 5 to 16 years
Partnerships and Community Involvement: Collaboration with 14 forest divisions along both sides of River Mahanadi, community participation, compensation for damaged fishing nets, and a reward for returning live gharial caught in the nets.
Monitoring and Research: Post-release monitoring by researchers played a pivotal role in understanding gharial behaviour and ecology in the Mahanadi habitat.
Threats and challenges: The project encountered several challenges, including the persistent threats of entanglement in nylon fishing nets and blasting activities, leading to injury and mortality of gharial. Conflicts with muggers and anthropogenic disturbances in the habitats compound their struggle for survival.

Impact

Natural Breeding has been recorded after 40 years in Satkosia Gorge Sanctuary, the site of project implementation, due to stringent protection efforts, implementation of the 'NO FISHING ZONE', research studies, and community awareness to reduce disturbances. Hatching of 28 hatchlings in May 2021, 32 hatchlings in May 2022 and 35 hatchlings in May 2023 have been recorded.
Hatchling Rescues: The provision of rewards has helped in the rescue of 7 gharial hatchlings caught in fishing nets downstream and handed over to authorities for post-rescue care and eventual release in a suitable habitat.
Community Awareness: Community participation and awareness initiatives have helped in a positive change in attitudes toward the conservation of Gharials.
Research Insights: The project has provided valuable insights into the ecology and behaviour of gharials in their southernmost habitat.

Way forward

Extensive Protection: Ensuring Gharial safety across the entire riverine habitat, with continued support from 14 forest divisions on either side of river Mahanadi and the constitution of a rapid response rescue team for rescue and rehabilitation of gharials.
Community Involvement: Raising public awareness and engaging local communities
Rehabilitation and Monitoring: Release of the remaining 16 captive-bred adult gharials into their natural habitat with double transmitter tagging for effective post-release tracking.
Genetic Study: Undertaking a genetic study to better understand the population's genetics.