Manatees and PFCs- The Future of Contaminant Studies

Kady Palmer, Eckerd College

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In my previous post, “The Problem with PFCs- Seeking Answers in Plasma”, the abundance of perfluorinated chemicals, or more specifically perfluoroalkyl acids (PFAAs), was analyzed in manatee plasma and correlated to variables such as site, water temperature, and blood chemistry. The purpose of this study was to develop a greater understanding of these chemical contaminants in regards to their routes of exposure and subsequent health effects.

Accumulation of PFAAs within organisms is proposed to be predominantly attributed through diet. Therefore, apex predators, like alligators, dolphins, and humans are found to be at a higher risk for increased concentrations of these chemicals in their body (Bangma et al., 2017, Fair et al., 2012). This is a result of biomagnification, or increasing levels of a compound as one continues up the food chain or trophic hierarchy. Manatees, however, are not predators, and are considered lower on the trophic hierarchy due to their herbivorous diet. With that knowledge, the amount of PFAAs within them, if any, was hypothesized to be very small.

After obtaining data from chemical extractions and liquid chromatography tandem mass spectrometry (LC-MS/MS), concentrations of at least two perfluoroalkyl acids were detected in all 69 manatee plasma samples. What that means is that PFAAs are integrating into the biological systems of manatees and accumulating within their bloodstream, presenting different results than our initial hypothesis.

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One of the most common PFAAs found in manatee plasma, known as perfluorooctanesulfonic acid (PFOS). Photo from: http://pubs.sciepub.com/ces/2/1/3/

Data and statistical analyses determined location-based differences in PFAA concentrations. In addition, correlations were found between high PFAA burden, blood chemistry measurements, and water temperature at the time of sampling. With this information, a basis for further investigations is possible to begin determining potential health effects of PFAAs in not only manatees, but in humans as well.

manateesCR

Because manatees cannot tolerate cold water, they congregate in warm waters during the winter seasons. Interestingly, correlations between water temperatures and PFAA values were found in this study. Photo from: http://proof.nationalgeographic.com/2014/07/21/floridas-manatees-the-search-for-warmer-water/

In summary, the purpose of this experiment was to answer two questions: 1) Are PFAAs present in manatee plasma? 2) If so, can heavy burdens of PFAAs be statistically correlated to health variables?

The first question was answered within the first week of analysis, simply by identifying detectable levels of these chemicals in manatee plasma. The second question, however, is more complicated to answer. The statistics say that there are associations between PFAAs and differing health measurements, however, the significance and meaning of that data is something future research must focus on. The reasons behind the correlations are still unknown, even though some explanations may be proposed.

I would like to extend an enormous thank you to everyone who made this project possible, including Dr. Jacqueline Bangma, Dr. Jessica Reiner, and my extremely motivating mentor, Dr. John Bowden. I would also like to thank the National Science Foundation for their funding, the College of Charleston’s Grice Marine Lab for hosting this REU, and the USGS Sirenia project for supplying the samples I utilized in this project.

References:

Bangma, Jacqueline T., John A. Bowden, Arnold M. Brunell, Ian Christie, Brendan Finnell, Matthew P. Guillette, Martin Jones, et al. “Perfluorinated Alkyl Acids in Plasma of American Alligators (Alligator Mississippiensis) from Florida and South Carolina.” Environmental Toxicology and Chemistry, no. 4 (2017a): 917. doi:10.1002/etc.3600.

Fair, Patricia A., Magali Houde, Thomas C. Hulsey, Gregory D. Bossart, Jeff Adams, Len Balthis, and Derek C.G. Muir. “Assessment of Perfluorinated Compounds (PFCs) in Plasma of Bottlenose Dolphins from Two Southeast US Estuarine Areas: Relationship with Age, Sex and Geographic Locations.” Marine Pollution Bulletin 64 (January 1, 2012): 66–74. doi:10.1016/j.marpolbul.2011.10.022.

 

Are Manatees the Key?

Kady Palmer, Eckerd College

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Contaminants. One word, countless different connotations. Therefore, the exposure to contaminants is a constant concern to both the public and the scientific community. The study I will be performing this summer focuses on perfluorinated chemicals, or PFCs. PFCs are a class of contaminants that are utilized in many commercially available products (ex: non-stick pans, stain resistant sprays, and water-resistant materials) and have been classified as highly abundant and persistent chemicals of concern, in relation to overall environmental and, subsequently, human health.

teflon

Photo from: “Should You Ban Your Teflon Pan? California.” Savvy California, January 1, 2015. https://savvycalifornia.com/teflon-pan-toxic-or-not/. 

Through various mechanisms, PFCs have been noted to integrate into the environment and end up in the air, soil, and water. As this is happening, the organisms living in these areas become exposed and are put into a precarious situation. Little research has been performed on examining exactly what the effect these compounds have on organisms in these types of environments. Although it would be just as interesting to scoop water samples from different places to determine a basis for this environmental change, my project will be delving a bit deeper. Because previous studies have shown data supporting PFC accumulation in the bloodstream of different marine animals and their subsequent health consequences, I will be expanding this research by analyzing the types and abundance of PFCs in the Florida manatee.

The Florida manatee (Trichechus manatus latirostris) inhabits areas of warm water, close to the shoreline. Unfortunately, manatees have a history of endangerment, as a result of human impacts (boat strikes, entanglements, drowning due to drainages) and environmental changes. Perfluorinated chemicals, as described above, could very well be impacting manatees in ways currently unknown. This study aims to isolate the types and abundance of PFCs in Florida manatees and potential health concerns associated with this exposure. While the health of manatees is undoubtedly important, the results of this research could provide insight as to the overall health of the ecosystems examined. Manatees could function as a model for other organisms, demonstrating the possible repurcussions of PFC exposure. If that is the case, the knowledge gained from this organism, living so close to the shoreline of human inhabited areas, may be applicable in aiding future human research.

manatee-cow-and-calf

Photo from: “West Indian Manatee.” Southeast Region of the U.S. Fish and Wildlife Service. Accessed June 23, 2017. https://www.fws.gov/southeast/wildlife/mammals/manatee/.

I’d like to sincerely thank everyone involved in the National Institute of Standards and Technology laboratories who have been a wealth of information and guidance, specifically Dr. Jessica Reiner, Jackie Bangma, and my mentor, Dr. John Bowden. This project would not be possible without samples and information provided by Robert Bonde with USGS, funding from the National Science Foundation, and the College of Charleston’s Grice Marine Laboratory.

References:

Bangma, Jacqueline T., John A. Bowden, Arnold M. Brunell, Ian Christie, Brendan Finnell, Matthew P. Guillette, Martin Jones, et al. “Perfluorinated Alkyl Acids in Plasma of American Alligators (Alligator Mississippiensis) from Florida and South Carolina.” Environmental Toxicology and Chemistry, no. 4 (2017): 917. doi:10.1002/etc.3600.

“CDC – NBP – Biomonitoring Summaries – PFCs.” Accessed June 19, 2017. https://www.cdc.gov/biomonitoring/pfcs_biomonitoringsummary.html.

West Indian Manatee”. Southeast Region of the U.S. Fish and Wildlife Service. Accessed June 23, 2017. https://www.fws.gov/southeast/wildlife/mammals/manatee/.