Sliteye Shark in Great Chagos Bank has been recorded for the first time, marking a significant milestone in marine research. The Great Chagos Bank, the world’s largest coral atoll, is renowned for its rich biodiversity, much of which remains unexplored. Researchers recently captured images of the elusive sliteye shark in deep seagrass habitats along the southern rim of the Bank. This discovery not only expands our understanding of the species but also underscores the ecological importance of deepwater seagrass meadows in the Chagos Archipelago and its Marine Protected Area.
Discovery of Sliteye Shark in Great Chagos Bank
Scientists used Baited Remote Underwater Video (BRUV) systems to document two sliteye sharks at locations only 11 kilometres apart, at depths between 23 and 29 metres. Characterized by their narrow, slit-like eyes, these sharks are adapted to see in low-light conditions. While sliteye sharks are typically found in deeper waters, they can also inhabit shallow, clear seas, making their presence in the Great Chagos Bank particularly noteworthy. This marks the first official record of the species in this unique coral atoll, opening new avenues for research into its behaviour and habitat preferences.
Significance of Deepwater Seagrass Habitats
The sliteye shark was observed within deepwater seagrass meadows that were initially mapped in 2016. These meadows extend deeper than previously thought, a fact revealed through satellite tracking of green turtles in the region. Seagrass meadows play a crucial role in supporting marine biodiversity. Over 110 fish species utilize these underwater grasslands for food and shelter. The presence of sliteye sharks highlights that these habitats are not only essential for fish but also for larger predators, reinforcing the ecological importance of deepwater seagrass ecosystems.
Protecting these meadows ensures that the intricate web of marine life continues to thrive. The discovery emphasizes the need for sustained monitoring and conservation of deepwater habitats, particularly in remote regions like the Chagos Archipelago.
Physical Features and Distribution of Sliteye Shark
The sliteye shark (Loxodon macrorhinus) is a small-bodied requiem shark, growing up to 95 cm in length. Its slender body and elongated face, coupled with large eyes having slit-like pupils, allow it to navigate and hunt effectively in dim environments. The shark’s small, smooth-edged teeth are suited to its diet, while its pale grey colouration with a white belly provides camouflage in open waters.
Sliteye sharks are distributed across tropical waters of the Indian and western Pacific Oceans, including regions along India, Australia, Japan, and East Africa. Despite their wide range, these sharks remain poorly studied, making discoveries like the one in the Great Chagos Bank invaluable for understanding their ecology and behaviour.
Conservation Status and Threats
The sliteye shark is listed as Near Threatened by the International Union for Conservation of Nature (IUCN), with populations projected to decline by approximately 30% over 15 years. Overfishing in coastal waters represents the primary threat to the species. The recent discovery in the Chagos Archipelago raises important questions about the abundance and habitat use of sliteye sharks in deeper oceanic zones.
Protecting deepwater seagrass habitats is critical for the conservation of this species, as these areas offer refuge and feeding grounds. Sustainable management of fishing activities and human interference is essential to safeguard the delicate balance of these ecosystems and ensure the survival of sliteye sharks along with other marine species in the Indian Ocean.
Implications of the Discovery
The finding of the sliteye shark in Great Chagos Bank underscores the ecological significance of the region. Deepwater seagrass meadows, often overlooked, are essential for sustaining a wide array of marine life. This discovery highlights the need for continued research into lesser-known habitats and species, which may hold vital clues about marine biodiversity and ecosystem health.
Moreover, the presence of sliteye sharks in these remote habitats reinforces the importance of maintaining strict protections in Marine Protected Areas. By managing human activities responsibly and promoting scientific research, policymakers and conservationists can ensure the preservation of unique species and fragile ecosystems.
Conclusion
The Sliteye Shark in Great Chagos Bank marks a remarkable addition to the known biodiversity of one of the world’s largest coral atolls. Its discovery highlights the ecological value of deepwater seagrass meadows and the urgent need for sustainable conservation efforts. Protecting these habitats will not only safeguard sliteye sharks but also support the broader marine ecosystem, ensuring that the Chagos Archipelago continues to thrive as a haven for marine life.
