Sea turtles - Green turtle, leatherback turtle, etc. - ecosystem component from the WIO Symphony tool

The sea turtle layer combines species distribution models (SDMs) with recorded nesting beaches. SDMs were produced for the Loggerhead sea turtle (Caretta caretta), Leatherback sea turtle (Dermochelys coriacea), Green sea turtle (Chelonia mydas) and Olive ridley sea turtle (Lepidochelys olivacea), using ensemble modelling with 25 predictor variables and observation records from the Ocean Biodiversity Information System (OBIS). Probability of occurrence maps produced in the SDM were then summed across all species, and the combined SDM was scaled from 1 to 10. A cost-distance layer was produced based on known nesting beaches, up to a maximum distance of 3 km. The resulting cost-distance was scaled from 10 to 100, such that a value of 100 indicates the pixel is within 1 km of a nesting beach. This layer was then combined with the SDMs, such that pixels within 3 km of nesting beaches were merged with priority. Known limitations: The species distribution models are based on available records, and therefore likely to contain observation bias. As such, the model is likely to overestimate occurrence in regions with many recorded observations of marine wildlife (e.g. South Africa) and underestimate occurrence in regions with few recorded observations of marine wildlife (e.g. Somalia).