Rehabilitate reptiles following oil spills

Overall effectiveness category Awaiting assessment
Number of studies: 1
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Effectiveness

not assessed
Certainty

not assessed
Harms

not assessed

Calculating overall effectiveness category

Background information and definitions

Oil spills are an obvious threat in marine and aquatic environments because the oil spreads quickly through the water column. The oil clings to animals, remains long-term in the environment, and is often ingested. Heavily oil-covered or chronically oil-exposed turtles may have respiratory, skin and shell problems. Oiled turtles are also known to have increased white blood cell counts, reduced red blood cell counts, increased numbers of immature red blood cells, acute inflammation of skin and mucosal surfaces (Lutcavage et al. 1995). Long-term consequences of oil exposure are not well understood, but a high incidence of embryo deformity is known from turtle populations with chronic oil exposure (Bell et al. 2006). Other long-term indirect problems may include delayed mortality due to hindgut bacterial death in marine iguanas (Wikelski et al. 2002) and an increase in disease (Milton et al. 2003).

Reptiles may be rescued, rehabilitated and released back into the wild following oil spills to mitigate the negative effects of exposure.

For other studies relating to the re-release of injured reptiles or accidentally captured reptiles see Species management – Rehabilitate and release injured or accidentally caught individuals and Biological resource use – Release accidentally caught (‘bycatch’) reptiles.

^{Bell B., Spotila J.R. & Congdon J. (2006) High incidence of deformity in aquatic turtles in the John Heinz National Wildlife Refuge. Environmental Pollution, 142, 457–465.}

^{Lutcavage M.E., Lutz P.L., Bossart G.D. & Hudson D.M. (1995) Physiologic and clinicopathologic effects of crude oil on loggerhead sea turtles. Archives of Environmental Contamination and Toxicology, 28, 417–422.}

^{Milton S., Lutz P. & Shigenaka G. (2003) Oil toxicity and impacts on sea turtles. Pages 35–47 in G. Shigenaka (eds.) Oil and Sea Turtles: Biology, Planning and Responses. NOAA Ocean Service, Seattle, Washington.}

^{Wikelski M., Wong V., Chevalier B., Rattenborg N. & Snell H.L. (2002) Galapagos Islands: marine iguanas die from trace oil pollution. Nature, 417, 607–608.}

Study locations

Key messages

One study evaluated the effects on reptile populations of rehabilitating reptiles following oil spills. This study was in the USA¹.

COMMUNITY RESPONSE (0 STUDIES)

POPULATION RESPONSE (1 STUDY)

Survival (1 study): One replicated study in the USA¹ found that almost all sea turtles that were de-oiled recovered and could be released.

BEHAVIOUR (0 STUDIES)

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

A replicated study in 2010 in two rehabilitation centres in Louisiana and Florida, USA (Stacy et al. 2017) found that almost all sea turtles that received de-oiling treatment following the BP Deepwater Horizon oil spill in the Gulf of Mexico were rehabilitated and released back into the wild. Following de-oiling treatment, almost all rehabilitated sea turtles recovered and were released, including 189 of 192 Kemp’s ridley Lepidochelys kempii, 112 of 113 green turtles Chelonia mydas, nine of nine loggerhead turtles Caretta caretta and five of five hawksbill turtles Eretmochelys imbricata). Three Kemp's ridley turtles died within 3 days and one green turtle was euthanised 142 days after admission (due to bacterial infection). Turtles (mainly juveniles with carapace length <25cm) were collected by crews patrolling the northern Gulf of Mexico and transported by vehicle from ports to rehabilitation facilities (1–3-hour journeys). Upon admission, turtles were weighed and measured (including blood samples). Turtles were de-oiled using multiple external cleanings using vegetable oil, mayonnaise and mild liquid detergent as well as oral doses of cod liver oil and oil. They were also provided with fluid therapy, and where necessary with vitamin B, iron and/or calcium supplements, antibiotics and veterinary treatment. A small number (15–20 individuals) also received oral charcoal. The dose and duration of petroleum exposure was unknown, but 139 turtles were classified as lightly oiled, 76 as moderately oiled, 46 as heavily oiled and 58 as severely oiled.
Study and other actions tested
Referenced paper
Stacy N.I., Field C.L., Staggs L., MacLean R.A., Stacy B.A., Keene J., Cacela D., Pelton C., Cray C., Kelley M., Holmes S. & Innis C.J. (2017) Clinicopathological findings in sea turtles assessed during the Deepwater Horizon oil spill response. Endangered Species Research, 33, 25-37.

Please cite as:

Sainsbury K.A., Morgan W.H., Watson M., Rotem G., Bouskila A., Smith R.K. & Sutherland W.J. (2021) Reptile Conservation: Global Evidence for the Effects of Interventions for reptiles. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

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This Action forms part of the Action Synopsis:

Reptile Conservation

Related Actions

Actions	Effectiveness	Studies	Category
Rehabilitate reptiles following oil spills Action Link	Awaiting assessment	1	Synopsis Link
Relocate reptiles (including eggs and hatchlings) following oil spills Action Link	Evidence not assessed	0	Synopsis Link
Regulate planning permission for gas/filling stations at reptile sites Action Link	No evidence found (no assessment)	0	Synopsis Link