Triple trouble for Gulf of Mannar islands, study finds 

An alien invasive plant is threatening to pulverise native vegetation throughout 21 islands within the Gulf of Mannar Biosphere Reserve (GoMBR), an avian distribution study has revealed. 

Prosopis chilensis, a drought-resistant plant native to the arid areas of 4 South American international locations — Argentina, Bolivia, Chile, and Peru — just isn’t the one trouble for these islands divided into the Tuticorin, Vembar, Kilakkarai, and Mandapam teams. 

The coral reef has been destroyed in a number of locations close to these islands though coral quarrying for industrial functions has been outlawed, the study printed within the Journal of Threatened Taxa stated. 

Human settlements, although not everlasting, have additionally impacted the islands equivalent to Poomarichan, Pullivasa, and Manoliputti within the Mandapam group, the study stated, whereas recording 96 species of birds on these islands. 

The authors of the study are H. Byju and S. Ravichandran of Annamalai University’s Centre of Advanced Study in Marine Biology, and N. Raveendran of the Madurai-based Iragukal Amritha Nature Trust. 

“Most of the islands have sand dunes along their coastlines with salt-dominant plant species. Some of the islands contain trees while the marshy sections of some of the islands are occupied by mangroves and allied species,” Dr. Byju instructed  The Hindu. 

“We found the  Prosopis chilensis in seven or eight islands. Any invasive species on an island will slowly kill the native trees as well as the mangroves as we have seen some overgrown to the edge of the islands near the high tide areas,” he stated. 

The scientists stated they may not discover any main research on the invasiveness of this species or the way it got here to India, in contrast to the equally invasive  Prosopis juliflora discovered within the Deccan Plateau, particularly Tamil Nadu, launched by the British in 1877 to inexperienced the arid tracts. 

While the native vegetation “has lost ground to”  Prosopis chilensis on some islands nearer to the coast, the study underlined the “indiscriminate destruction of marine life” persevering with regardless of efforts to coach and monitor the fishing neighborhood. 

Of the 96 fowl species belonging to 34 households from 13 orders that they recorded, 58 have been waterbirds whereas the others have been terrestrial, the researchers discovered. Photo: Special Arrangement

“Corals, seagrass, and mangroves are among the three unique ecosystems present on the islands,” the study stated, declaring that the coral reef was past conservation in a number of locations. 

The study cautioned about short-term settlements on the Mandapam group of islands primarily as a result of of the use of the vegetation on the islands for cooking. Deployment of conventional fishing gear was additionally occasionally recorded, particularly near the mangrove fringes of many islands, which supply a super foraging floor for massive wading birds. 

The scientists didn’t discover some of the sooner recorded species throughout their survey to replace the distribution of the fowl teams on the 21 islands from 2015 to 2022. Of the 96 species belonging to 34 households from 13 orders that they recorded, 58 have been waterbirds whereas the others have been terrestrial. 

Of the 29 shorebird species recorded, one is endangered and 7 are marked near-threatened within the Red List of the International Union for Conservation of Nature. 

The GoMBR, India’s first marine biosphere reserve, is one of the vital habitats for coastal birds migrating so far as the Arctic Circle. The space is of explicit significance because the 21 islands additionally function resting locations for birds migrating to and from the close by Sri Lankan islands. 

The highest quantity of water fowl species, inclusive of waders, geese, terns, gulls, egrets, and herons,was recorded on Manoli island of the Kilakkarai group. But 19 species of shorebirds have been recorded in comparison with 26 listed in a 1990 study. 

The Kentish plover, ruddy turnstone, lesser black-backed gull, larger crested tern, little cormorant, nice egret, Indian pond heron, and Brahminy kite have been amongst 12 species of birds discovered on all of the islands. But many have been recorded on just one island. These included the white-breasted tern and wooden sandpiper (on Manoli island), pin-tailed snipe (on Musal island), larger thick-knee (on Shingle island), and Eurasian spoonbill, pied kingfisher and Indian curler (on Kurusadai island).