We investigated the extent that the 2010 Deepwater Horizon oil spill potentially affected oceanic-stage sea turtles from populations across the Atlantic. Within an ocean-circulation model, particles were backtracked from the Gulf of Mexico spill site to determine the probability of young turtles arriving in this area from major nesting beaches. The abundance of turtles in the vicinity of the oil spill was derived by forward-tracking particles from focal beaches and integrating population size, oceanic-stage duration and stage-specific survival rates. Simulations indicated that 321 401 (66 199–397 864) green (Chelonia mydas), loggerhead (Caretta caretta) and Kemp's ridley (Lepidochelys kempii) turtles were likely within the spill site. These predictions compared favourably with estimates from in-water observations recently made available to the public (though our initial predictions for Kemp's ridley were substantially lower than in-water estimates, better agreement was obtained with modifications to mimic behaviour of young Kemp's ridley turtles in the northern Gulf). Simulations predicted 75.2% (71.9–76.3%) of turtles came from Mexico, 14.8% (11–18%) from Costa Rica, 5.9% (4.8–7.9%) from countries in northern South America, 3.4% (2.4–3.5%) from the United States and 1.6% (0.6–2.0%) from West African countries. Thus, the spill's impacts may extend far beyond the current focus on the northern Gulf of Mexico.
Putman et al. Supplemental Tables - BL
Supplemental Tables
Description of Supplemental Excel Tables (names are different tabs within the Excel Workbook)
Table S1. Connectivity. Table listing hatchling abundance, by species, for each nesting area and connectivity between those areas and the spill site. Percentage of particles backtracked from the spill site arriving from each of the nesting areas of green, loggerhead, and Kemp’s ridley turtles within a given year, scaled relative to the number of particles that encountered any nesting area during that same period.
Table S2. Literature-Survival. Table of data used for estimating clutch size (number of eggs per nest), clutch survival, and oceanic survival.
Table S3. Green (number). The number of each age class of surface-pelagic green turtles from each of the twenty-four nesting areas estimated to be at the spill site based on median, maximum, and minimum estimates of oceanic survival.
Table S4. Loggerhead (number). The number of each age class of surface-pelagic loggerhead turtles from each of the eight nesting areas estimated to be at the spill site based on median, maximum, and minimum estimates oceanic survival.
Table S5. Kemp’s ridley (number). The number of each age class of surface-pelagic Kemp’s ridley turtles from each of the four nesting areas estimated to be at the spill site based on median, maximum, and minimum estimates of oceanic survival. Table includes results for passive drift “retentive behavior” simulations.
Table S6. Green (percent). The percentage of survivors of each age class of oceanic-stage green turtles from each nesting area estimated to be at the spill site.
Table S7. Loggerhead (percent). The percentage of survivors of each age class of oceanic-stage loggerhead turtles from each nesting area estimated to be at the spill.
Table S8. Kemp’s ridley (percent). The percentage of the total survivors of each age class of surface-pelagic Kemp’s ridley turtles from each nesting area estimated to be at the spill site. Table includes results for passive drift “retentive behavior” simulations.
