A study commissioned by the Mangrove and Marine Biodiversity Conservation Foundation of Maharashtra on the ecologically vulnerable Vengurla Rocks in Sindhudurg district of Konkan Maharashtra prompted the foundation to look into options for better protecting and conserving the area.
Between January and June 2020, researchers Shirish Manchi, Goldin Quadros and Dhanusha Kawalkarthe of the Salim Ali Centre for Ornithology and Natural History (SACON) explored the island of the Vengurla rocks region and discovered four caves. However, only one of the caves, named Pakholi Dhol on the Burnt Island, could be reached by the team.
Based on the cave’s inherent visibility, it was divided into three zones: the entrance zone, the twilight zone, and the black zone. One of the major conclusions of the study was the threat posed to the delicate cave ecosystems and their biodiversity by climate change and the rising sea level.
Quadros, a wetland scientist, explained that the Vengurla archipelago is unique to the Sindhudurg coast. The archipelago comprises 20 islets of which three are comparatively large, including New Lighthouse island, Old lighthouse island and Burnt island. Among the remaining, nine are small islands while eight are submerged rocks.
“These islets are important coastal forms that secure the coastal population by acting as barriers. Moreover, the presence of the Indian swiftlet bird in Vengurla creates a niche ecosystem that supports species that are still unknown and unidentified. The changing climate can lead to rise in the sea level which can adversely impact the cave’s invertebrate diversity. Moreover, such habitats need protection from any kind of tourism,” clarified Quadros.
During the study, SACON recorded 21 invertebrates in Pakholi Dhol, including spiders, beetles, crabs, moths and butterflies, dragonflies, crickets, christmas tree worms, silverfish and barnacles. The study identified five vertebrate orders, including three birds — swiftlets, pigeons and martins — along with one mammal (rodent) and reptile (gecko).
Interestingly, the researchers found that a good population of Indian swiftlets are known to nest in the Pakholi caves and the team found 4,700 birds nesting in the caves. SACON developed two and three dimensional maps of the caves during the study. The researchers also undertook outreach programmes across local schools and colleges in Sindhudurg district informing the locals about the conservation value of these caves, a press note of Mangrove protection cell said.
Virendra Tiwari, Additional Principal Chief Conservator of Forest, Mangrove Cell and Executive Director, Mangrove Foundation explained that based on the findings of the study, the Mangrove Cell and Foundation is exploring the possibilities of ensuring better protection of this site and building awareness for the local community.
“The study was carried out to comprehend the cave fauna of the Vengurla rocks archipelago, a series of offshore islands along the Sindhudurg coast of Maharashtra, in light of the significance of the cave habitats and the risks they are susceptible to. Additionally, it will enable us to understand the ecosystem services provided by these caves and their conservation importance for the local community and sustainable development through alternate sources of income. Additionally, the location and geology make it crucial to document the ecological richness,” said Tiwari.