Breeding colonies of six more seabirds recorded in unique sandbars of Adam’s Bridge

Breeding colonies of six seabird species recorded in unique sandbars of Adam’s Bridge sandbars, emphasizing the need for conservation efforts.

Cementing the conservation potential of the unique marine ecosystem of Adam’s Bridge (Ram Setu) in the Gulf of Mannar Biosphere Reserve, a group of researchers, in collaboration with the Tamil Nadu Forest Department, have found breeding colonies of six species of seabirds on the sandbars between Rameswaram Island and Sri Lanka.

Breeding colonies of Brown noddy, Bridled Tern, Saunder’s Tern, Little Tern, Greater Crested Tern and Roseate Tern were recorded on these sandbars, 8 km south-east of Arichalmunai, near the Sri Lankan maritime boundary. The findings were published in the Journal of Threatened Taxa.

“The closest known breeding colonies of Brown noddies were on Cherbaniani Reef and Pitti island of Lakshadweep, Sri Lanka and Maldives. The breeding colonies of Brown Noddy documented on sandbar VII of Adam’s Bridge in July 2024 is the first confirmed nesting of the species along the southeastern coast of India,” said H. Byju, a researcher from the Centre of Advanced Sciences in Marine Biology, Annamalai University, who co-authored the findings with H. Maitreyi, N. Raveendran and D.A. Marshal.

According to Mr. Byju, sandbars I to VII are largely undisturbed by humans due to restricted access. The 2.5 km-long and 1.5 km-wide sandbar VII is made of sand dunes and shallow seawater pools.

The four researchers, along with S. Ravichandran, found breeding colonies of the five terns, namely Bridled Tern, Saunder’s Tern, Little Tern, Greater Crested Tern and Roseate Tern, on sandbars III and VII between June and August, 2024. Sand bar III is 600 metre-long and 250 metre-wide.

The researchers also observed several dead bird carcasses from the colonies during surveys and reasons could not be ascertained. Though human interference is minimal, rare instances of poaching of eggs and birds, pollution in the form of plastic bottles and discarded fishing gears are cause of concern. Researchers also learnt that fishermen or poachers from the Sri Lankan side transgress sandbar VII on the Indian side to collect eggs and birds using speed boats.

“Breeding colonies of these pelagic birds stresses the need for improved conservation efforts on the sandbars connecting India and Sri Lanka,” adds Mr. Byju.