A novel approach to estimate the distribution, density and at-sea risks of a centrally-placed mobile marine vertebrate

作者：Pikesley Stephen K; Agamboue Pierre Didier; Bayet Jean Pierre; Bibang Jean Noel; Bonguno Eric Augowet; Boussamba Francois; Broderick Annette C; Coyne Michael S; Du Plessis Philippe; Faure Francois Edgard; Fay J Michael; Formia Angela; Godley Brendan J; Kema Judicael Regis Kema; Mabert Brice Didier Koumba; Manfoumbi Jean Churley; Asseko Georges Mba; Metcalfe Kristian; Minton Gianna; Nelms Sarah; Ngouessono Solange; Nzegoue Jacob; Ogandanga Carole

来源：Biological Conservation, 2018, 221: 246-256.

DOI：10.1016/j.biocon.2018.03.011

• Inter-nesting
• Leatherback turtles
• Marine protected area (MPA)
• Spatial analysis
• Automatic Identification System (AIS)
• Vessel Monitoring System (VMS)

Formulating management strategies for mobile marine species is challenging, as knowledge is required of distribution, density, and overlap with putative threats. As a step towards assimilating knowledge, ecological niche models may identify likely suitable habitats for species, but lack the ability to enumerate species densities. Traditionally, this has been catered for by sightings-based distance sampling methods that may have practical and logistical limitations. Here we describe a novel method to estimate at-sea distribution and densities of a marine vertebrate, using historic aerial surveys of Gabonese leatherback turtle (Derrnochelys coriacea) nesting beaches and satellite telemetry data of females at sea. We contextualise modelled patterns of distribution with putative threat layers of boat traffic, including fishing vessels and large ship movements, using Vessel Monitoring System (VMS) and Automatic Identification System (AIS) data. We identify key at-sea areas in which protection for inter-nesting leatherback turtles could be considered within the coastal zone of Gabonese Exclusive Economic Zone (EEZ). Our approach offers a holistic technique that merges multiple datasets and methodologies to build a deeper and insightful knowledge base with which to manage known activities at sea. As such, the methodologies presented in this study could be applied to other species of sea turtles for cumulative assessments; and with adaptation, may have utility in defining critical habitats for other central-place foragers such as pinnipeds, or sea bird species. Although our analysis focuses on a single species, we suggest that putative threats identified within this study (fisheries, seismic activity, general shipping) likely apply to other mobile marine vertebrates of conservation concern within Gabonese and central African coastal waters, such as olive ridley sea turtles (Lepidochelys olivacea), humpback dolphins (Sousa teuszip and humpback whales (Megaptera novaeangliae).

• 出版日期2018-5