Toxicological estimation of mortality of oceanic sea turtles oiled during the Deepwater Horizon oil spill

Using estimates of the oil ingested by oceanic sea turtles and comparing them to toxic endpoints following oil ingestion in turtles and other vertebrate species, we derived an estimated percentage of mortality for oil-exposed oceanic sea turtles.

Oil ingestion (mg kg(-1) BW d(-1)) in oceanic sea turtles was estimated based on extent of oiling categories assigned by a sea turtle technical working group (STTWG) as follows: non-oiled (0), minimally oiled (1), lightly oiled (2), moderately oiled (3) and heavily oiled (4). Because the STTWG concluded that 100% of heavily oiled turtles would have died from the physical effects of heavy oiling, we limited our assessment of mortality to turtles in categories 0 to 3 and estimated how many of these turtles would have died from ingestion of oil.