Conservation of reef manta rays (Manta alfredi) in a UNESCO World Heritage Site: Large-scale island development or sustainable tourism?

• Published in: PloS one 2017-10, Vol.12 (10), p.e0185419-e0185419
• Main Authors: Kessel, Steven Thomas, Elamin, Nasreldin Alhasan, Yurkowski, David James, Chekchak, Tarik, Walter, Ryan Patrick, Klaus, Rebecca, Hill, Graham, Hussey, Nigel Edward
• Format: Article
• Language: English
• Subjects: Analysis; Animals; Atlantic manta; Bayesian analysis; Biology and Life Sciences; Boundaries; Coasts; Computer simulation; Computers; Conservation; Conservation of Natural Resources; Coral Reefs; Disruption; Earth Sciences; Ecology and Environmental Sciences; Economic development; Ecotourism; Environmental aspects; Environmental protection; Environmental research; Funding; Habitats; Historic sites; Home range; Influence; Investigations; Islands; Manta birostris; Marine protected areas; National parks; People and Places; Physical Sciences; Protected areas; Protection and preservation; Skates, Fish; Software; Spatial distribution; State space models; Sustainable development; Sustainable tourism; Switching; Tags; Tourism; Travel; Wildlife; Wildlife conservation; World Heritage Areas
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0185419

A large reef manta ray (Manta alfredi) aggregation has been observed off the north Sudanese Red Sea coast since the 1950s. Sightings have been predominantly within the boundaries of a marine protected area (MPA), which was designated a UNESCO World Heritage Site in July 2016. Contrasting economic development trajectories have been proposed for the area (small-scale ecotourism and large-scale island development). To examine space-use, Wildlife Computers® SPOT 5 tags were secured to three manta rays. A two-state switching Bayesian state space model (BSSM), that allowed movement parameters to switch between resident and travelling, was fit to the recorded locations, and 50% and 95% kernel utilization distributions (KUD) home ranges calculated. A total of 682 BSSM locations were recorded between 30 October 2012 and 6 November 2013. Of these, 98.5% fell within the MPA boundaries; 99.5% for manta 1, 91.5% for manta 2, and 100% for manta 3. The BSSM identified that all three mantas were resident during 99% of transmissions, with 50% and 95% KUD home ranges falling mainly within the MPA boundaries. For all three mantas combined (88.4%), and all individuals (manta 1-92.4%, manta 2-64.9%, manta 3-91.9%), the majority of locations occurred within 15 km of the proposed large-scale island development. Results indicated that the MPA boundaries are spatially appropriate for manta rays in the region, however, a close association to the proposed large-scale development highlights the potential threat of disruption. Conversely, the focused nature of spatial use highlights the potential for reliable ecotourism opportunities.