Sea Turtle Threat Series: Pollution & Pathogens

By NATHAN ROBINSON & BRYAN WALLACE

A Kemp’s ridley turtle swims out from under an oil slick as rescue workers attempt to capture the animal for rehabilitation. Unfortunately, this turtle could not be successfully captured. © Carolyn Cole / Los Angeles Times

Amidst this global pandemic, many of you might have wondered whether sea turtles can catch COVID-19? While we cannot answer that question, we can point you in the direction of some great material from SWOT Reports on the impacts on sea turtles from pollution and pathogens! Welcome to the 3rd in a series of SWOT-sponsored guest editorials about the major threats to sea turtles, and thanks to Nick Pilcher and Brad Nahill for kicking things off with their overviews on Fisheries Bycatch (April 29) and Direct Take (May 15).

The effects of marine pollution on sea turtles are disturbingly ubiquitous. Several studies have suggested that almost all adult sea turtles will ingest plastic during their lifetime, while countless other turtles will become entangled in discarded fishing gear. These stories have gained considerable attention from the media in recent years, with sea turtles becoming the ‘poster child’ for the fight against plastic pollution. Yet it is important to remember that if we focus exclusively on marine plastics, we will underestimate the true extent of the pollution problem.

Chemical pollutants are just as widespread as marine plastic and we are only beginning to fully understand how they affect marine life. Thousands of oil spills have been documented in sea turtle habitats over the past half a century, yet only in a tiny number of those incidents have the effects on sea turtles been reported. Even in areas far away from any known oil spills, heavy metals, including arsenic and mercury, have been recorded in sea turtles at concentrations far exceeding natural levels. In turn, these pollutants can be passed onto these turtles’ offspring and even to humans or other animals that may eat these eggs.

Exposure to ocean chemical pollutants has been linked to several physiological abnormalities, such as weakened immune responses. It has even been connected to the proliferation of previously benign diseases. For example, studies have suggested a link between chemical pollutants and the rapid proliferation of fibropapilloma in green turtles, both of which have advanced over the past half century.

Tackling the issue of marine pollution requires global efforts. Fortunately, there is growing media coverage on ocean pollution and the dangers it poses to marine life. Sad as they may be, images of turtles smothered in oil after the Deepwater Horizon Oil Spill, of plastic objects being removed from turtles’ nostrils, and of turtles entangled in ghost-nets have generated unprecedented public outcry and support for initiatives to tackle this problem.

To learn more about this important issue, we invite you to take a tour through some of SWOT Report’s Greatest Hits on Pollution and Pathogens.

Best,

Nathan Robinson and Bryan Wallace

SWOT Report Articles Related to Pollution and Pathogens

Sea Turtles and Marine Debris/Plastics

1. Cohen, R. 2008. "There's a Great Future in Plastics…". In SWOT Report—The State of the World’s Sea Turtles, vol. 3: 28-29.

2. Gunn, R., & Veenstra, T. 2009. Ghostnets. In SWOT Report—The State of the World’s Sea Turtles, vol. 4: 31-33.

3. Savage, A., Lamilla, I., & Guillen, R. 2010. Totebags from Trash Help Turtles and Tamarins. In SWOT Report—The State of the World’s Sea Turtles, vol. 5: 40-41.

4. Duncan, E. 2016. Turtles and Plastic - A Case for More Action. In SWOT Report—The State of the World’s Sea Turtles, vol. 11: 6-7.

5. González-Paredes, D., & Estrades, A. 2018. Addressing the Plastic Pollution Challenge in Uruguay. In SWOT Report—The State of the World’s Sea Turtles, vol. 13: 42-43.

6. Miaud, C., & Darmon, G. 2020. Turtles Help Tackle Ocean Plastic Pollution in Europe. In SWOT Report—The State of the World’s Sea Turtles, vol. 15: 36-37.

Sea Turtles and Pollution / Pathogens

1. Marsh, J., & Nichols, W. J. 2007. Making the Connection: Human Health and Sea Turtle Consumption. In SWOT Report—The State of the World’s Sea Turtles, vol. 2: 39.

2. Schaf, S., & Work, T. 2007. The Mystery of the Tumors - what causes Fibropapillomas? In SWOT Report—The State of the World’s Sea Turtles, vol. 2: 12.

3. Witherington, B., Pendoley, K., Hearn, G., & Honarvar, S. 2009. Ancient Mariner, Ancient Fuels - How Sea Turtles Cope with Our Modern Fossil Fuel Dependency. In SWOT Report—The State of the World’s Sea Turtles, vol. 4: 38-41.

4. Witherington, B., & Jones, T. T. 2011. When Disaster Strikes (Deepwater Horizon Oil Spill). In SWOT Report—The State of the World’s Sea Turtles, vol. 6: 16-21.

5. Wibbels, T., & Bevan, E. 2015. New Riddle in the Kemp's Ridley Saga. In SWOT Report—The State of the World’s Sea Turtles, vol. 10: 14-17.

6. Thomé, J. C., De Martini, E., Colman, L., Marcondes, A. C. J., Baptistotte, C., Tiradentes Pizetta, G., Leite, N., & Tavares, S. 2017. A Dam Disaster in Brazil and its Impacts on Distant Sea Turtles. In SWOT Report—The State of the World’s Sea Turtles, vol. 12: 36-37.

7. Heffernan, A. L., Villa, C. A., & Madden Hof, C. A. 2018. Green Turtles as Silent Sentinels of Pollution in the Great Barrier Reef. In SWOT Report—The State of the World’s Sea Turtles, vol. 13: 8-9.

8. Renan Santos, M., & Nóbrega, Y. 2018. Scientific Tourism, Fibropapillomatosis, and Learning to Stay Out of Nature's Way. In SWOT Report—The State of the World’s Sea Turtles, vol. 13: 46-47.

9. Perrault, J. R., Foley, A. M., Flewelling, L. J., & Manire, C. A. 2019. Florida’s Red Tides and Their Impacts on Sea Turtles. In SWOT Report—The State of the World’s Sea Turtles, vol. 14: 10-11.

Stay tuned for more in this series based on “The 5 Biggest Threats to Sea Turtles” 2006. Their Greatest Challenge in 100 Million Years: Facing the Hazards of Humankind. In SWOT Report—The State of the World’s Sea Turtles, vol. 1: 5.