Should we say no to Nonylphenol?

Meagan Currie, Swarthmore College

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The ocean is approximately 1.3 billion cubic kilometers (Eakins, 2010). A single cubic kilometer can hold 400,000 Olympic-sized pools. So much does it really matter if human-made chemicals end up in our oceans? What could such small concentrations of chemicals really do to marine organisms?

These are the questions that are fueling my research project this summer at the Hollings Marine Laboratory. I have the privilege of working in the lab of Dr. Cheryl Woodley, who specializes in marine toxicology and coral health. Here I will be using two environmentally and biologically important marine organisms – sea urchins and coral – to understand more about the effects of manmade chemicals on the health and development of marine life.

Of course, given our limited time I am not going to investigate all of the over 70,000 different chemicals produced by the US. I will focus on the compound  nonylphenol, which has been recognized by the US Environmental Protection Agency (EPA) as a chemical of emerging concern (US EPA, 2012). This forbidding title is given to chemicals that have been recently detected in the natural environment that are believed to have harmful effects on humans and natural wildlife.

Nonylphenol is added to products as a detergent, as it helps dissolve oils and other compounds more easily in water, and is produced and distributed in very large quantities.  Approximately 500 million pounds of nonylphenol is produced every year, although in the last ten years the EPA has developed new rules to attempt to limit its application in products (Helmut, 2002; US EPA, 2016).  It is used in most commercial laundry detergents, soaps and cleaners, meaning that it often funnels down the drain and into wastewater treatment plants, or even directly into seawater . Unfortunately, nonylphenol isn’t broken down easily and is moderately bioaccumulative, meaning that it collects and remains in the systems of organisms that come into contact with the chemical.

Another element of nonylphenol’s chemical story is that it is an endocrine disruptor. This means that nonylphenol behaves like a common biological hormone, estrogen, and can negatively impact the hormonal systems of organisms. Marine invertebrates are particularly vulnerable to endocrine disruptors because many, including sea urchins and coral, exist as tiny, free-swimming organisms at early stages of development. Early embryos and larvae are known to be more susceptible to the effects of toxins, particularly hormonal disruptors, than adult organisms (Shirdel, 2016).

This summer I will work with the gametes (egg and sperm) and juveniles of the lovely sea urchin Lytechinus variegatus. This species of urchin is native to much of coastal South America as well as Florida and South Carolina.

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Lytechinus variegatus in the lab

I will see how sea urchin sperm responds to nonylphenol at different concentrations, and whether or not exposure affects the ability of sperm to fertilize eggs. I will also watch the development of sea urchin larvae exposed to the chemical to see if nonylphenol changes the pace or physiology of developing urchins. Finally, I will investigate the effects of nonylphenol on regrowth and regeneration of one of the most important organisms in our oceans: coral. Coral reefs host nearly a quarter of all marine species and are critical to maintaining the biodiversity and resources that we derive from the oceans (Coral Reef Alliance, 2017).  If you want to know more about coral reefs and maintaining reef health, you can follow the Coral Reef Alliance blog, which releases recent information about efforts to protect coral.

http://coral.org/blog/

I will be examining how a threatened species of coral, Acropora cervicornis, responds to nonylphenol. To do this I will see how nonylphenol influences the speed and effectiveness of recovery if the coral tissue is injured and then exposed to the chemical. I will also gauge how healthy the coral is by measuring how much the coral is photosynthesizing, which will tell us about how much energy it is producing.

I am very excited to be working with two incredible marine model organisms, and investigate such a prevalent and interesting compound! Our results will hopefully better inform the US EPA and other organizations about the threats of nonylphenol to marine aquatic environments and the many organisms that may be exposed at different stages of their lifecycle. Many thanks to Dr. Cheryl Woodley for welcoming me into her lab, and to the Fort Johnson Summer REU program for giving us this incredible experience.

Funding Sources

 

References

International Trade Administration. Chemical Spotlight: “The Chemical Industry in the United States.” Select USA; US Department of Commerce. Web. https://www.selectusa.gov/chemical-industry-united-states. Accessed Jun 22, 2017.

US EPA., 2012. DfE Alternatives Assessment for Nonylphenol Ethoxylates. Design for the Environment. United States Environmental Protection Agency. pp. 2-27.

Helmut Fiege, Heinz-Werner Voges, Toshikazu Hamamoto, Sumio Umemura, Tadao Iwata, Hisaya Miki, Yasuhiro Fujita, Hans-Josef Buysch, Dorothea Garbe, Wilfried Paulus “Phenol Derivatives” in Ullmann’s Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim.doi:10.1002/14356007.a19_313

US EPA., 2016. Nonylphenol and Nonylphenol Ethoxylates: Assessing and Managing Chemicals under TSCA. United States Environmental Protection Agency, 2 Nov. 2016. Web. https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/risk-management-nonylphenol-and-nonylphenol-ethoxylates. Accessed 12 Jun, 2017.

Kay, Jane. D4 and nonylphenol in textiles, plastics. Environmental Health News. May 6, 2013. Web. http://www.environmentalhealthnews.org/ehs/news/2013/d4-and-nonylphenol. Accessed June 20, 2017.

Brown, Mark Anthony et al. Microplastic moves pollutants and additives to worms, reducing functions linked to health and biodiversity. Current Biology. 23 (23): 2388-2392.

Eakins, B.W. and G.F. Sharman, Volumes of the World’s Oceans from ETOPO1, NOAA National Geophysical Data Center, Boulder, CO, 2010.

Shirdel, Iman. Kalbassi, Mohammad Reza. Effects of Nonylphenol on Key Hormonal Balances and Histopathology of the Endangered Caspian Brown Trout (Salmo Trutta Caspius). Elsevier Inc. PubMed: 26811907 DOI: 10.1016/j.cbpc.2016.01.003

Coral reef alliance. 2017. Coral Reef Ecology: Biodiversity. url. http://coral.org/coral-reefs-101/why-care-about-reefs/biodiversity/

Fatal before fertilization?

Cecilia Bueno, Lewis & Clark College

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Male Squirrel Treefrog (Hyla squirella) calling for a mate (credit)

Amphibians, including frogs, toads, salamanders, newts, and others, are experiencing large declines in populations worldwide1. Many factors human-caused factors are contributing to this decline, including habitat loss, to climate change, and pollution1.

One way that habitats are being damaged is by increased salinity in normally freshwater systems. Salt is getting into freshwater by use of salt road deicers, poor land irrigation, rising tidelines, and increased storm surges2. Changes in water quality, such as salinity, is especially dangerous to amphibians such as frogs because of their permeable skin.

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Breeding pair of Green Treefrogs (Hyla cinerea) in amplexus (credit)

In addition to increased salt levels harming adult frogs, it can damage developing frogs from fertilization onwards. Almost all frogs are external fertilizers- that is, when they breed, male and female join in amplexus and release sperm and egg into the water. Frogs require freshwater to breed and develop as tadpoles, so when freshwater is intruded by salt, there are problems for frogs from their earliest stages.

Many studies have shown that even low levels of salinity can cause tadpoles to develop abnormally, have lower adult weights, and die.While we already know that increased salinity has a bad effect on tadpoles, little is known about how this salinity affects frogs at the first stage of life: fertilization.

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First stages of embryonic development (credit)

 

We hope to look at the effects of salinity on sperm and fertilization, an area which has very little research currently. Previous research has shown that in squirrel treefrogs, low levels of salinity can stop eggs from being fertilized4. A study on green treefrog sperm showed that as salinity increased, sperm function decreased incrementally5. These two closely related species live in the Coastal Plains habitat, which is at risk of salinization by rising tides and storm surges. Sperm function and fertilization rates have been shown to be negatively by increased salinity- we look at these two effects in squirrel treefrogs and see if a decrease in sperm function can explain at least part of how salinity hinders fertilization.

I would like to thank the National Science Foundation for funding this REU program, and the Grice Marine Lab of the College of Charleston for hosting us. In particular, I would like to thank my mentor Dr. Allison Welch for her help and support.

References:

1:http://www.amphibiaweb.org/declines/declines.html

Stuart, S. N., J. S. Chanson, N. A. Cox, B. E. Young, A. S. L. Rodrigues, D. L. Fischman, and R. W. Waller. 2004. Status and trends of amphibian declines and extinctions worldwide. Science 306:1783–1786. CrossRefPubMed

2: Williams, W. D. 2001. Anthropogenic salinisation of inland waters. Hydrobiologia 466:329–337. CrossRef

Van Meter, R.J., Swan, C.M., Leips, J. et al. (2011) Salinity Acclimation Affects Survival and Metamorphosis of Crab-Eating Frog Tadpoles. Wetlands, 31: 843. doi:10.1007/s13157-011-0199-y

3:Alexander, Laura G., Simon P. Lailvaux, Joseph H. K. Pechmann, and Philip J. DeVries. “Effects of Salinity on Early Life Stages of the Gulf Coast Toad, Incilius Nebulifer (Anura: Bufonidae).” Copeia 2012, no. 1 (2012): 106-14. http://www.jstor.org/stable/41416605

Brown, Mary E., Walls, Susan C. (2013). Variation in Salinity Tolerance among Larval Anurans: Implications for Community Composition and the Spread of an Invasive, Non-native Species. Copeia, Sep 2013 : Vol. 2013, Issue 3, pg(s) 543-551 doi: 10.1643/CH-12-159

4:Unpublished data, Ruby and Welch

5: Wilder, Anneke E., Welch, Allison M. (2014). Effects of Salinity and Pesticide on Sperm Activity and Oviposition Site Selection in Green Treefrogs, Hyla cinerea. Copeia, 2014, No. 4, 659–667

 

What can baby shrimp teach us about oil spills?

Deanna Hausman, University of Texas at Austin

Pretty much everyone knows that oil is toxic, unfortunately. We’ve all seen images of birds or otters covered in oil, or seen wetlands destroyed due to an oil spill. But what many people may not know is certain factors, even rays from the sun, can increase the toxicity of oil. UV light—what gives us sunburns—can increase the toxicity of oil by over 1000 times in some cases, which allows it to kill more organisms and damage more of the ecosystem.

This is a big problem. And like in everything else, you can’t start solving a problem until you completely understand it. Before experts can start to clean up an oil spill, they have to make predictions, and determine how toxic the oil is going to be, what organisms are going to be more sensitive to it, and what conditions exist that could make the oil more toxic.

Which is where my research comes in! This summer, I’m studying the effects of oil on larval grass shrimp. They’re kind of cute little creatures: as larvae, they swim upside-down, and have giant eyes. Most importantly, as adults, they’re very important to the ecosystem. They’re an important food source for many larger fish and crabs, and they’re also detrivores, meaning they break down waste on the seafloor into smaller pieces, that tiny organisms such as plankton can eat. Therefore, they’re important for organisms both at the top and bottom of the food chain, and if their populations are harmed, it can have a huge negative impact on a large number of other organisms.

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Adult grass shrimp

Specifically, my work this summer is focusing on the toxic effects of thin oil sheens and oil mixed in with sediment, as well as the developmental effects of oil. Previously, some studies have worked to determine that very thin oil sheens can be toxic, but they largely focused on deep-water organisms, not estuarine species. My study will work to determine how thin oil sheens can affect estuarine species.  In addition, the sediment tests will determine how estuarine species might be affected by oil sinking down after a spill- a situation they are often exposed to. Both these studies will also evaluate what impact UV light has on oil in these situations. Finally, studying the impact of oil on shrimp development will help determine what the long-term affects an oil spill may have.

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The set-up of the oil sheen experiment. One tank contains pure seawater, to serve as a control, while the other contains the oil sheen. Some shrimp are caged and some are swimming free, in order to determine whether shrimp need to swim through the oil to be affected or not

All of this research will help people to make predictions about the damage that will occur in the event that an oil spill does occur in or near an estuary.

I’d like to thank my mentors, Dr. Marie Delorenzo and Dr. Paul Pennington, for their guidance and NOAA for providing me with lab space and equipment.

Works cited:

Finch, B.; Stubblefield, W. Photo-enhanced toxicity of fluoroanthene to Gulf of Mexico marine organisms at different larval ages and ultraviolet light intensities. Environmental Toxicology and Chemistry. 2015, 35, 1113-1122.

A Seaweed to beat them all

Killian Campbell, Eastern Washington University

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“Gracilaria vemiculophylla”.

Does anything even remotely familiar come to mind when you read those words? If you’re like most people, the answer is probably “no”. However, this strange red seaweed is actually quite ubiquitous, and chances are it dwells somewhere along the coast of the country you live in.

To most of the world, Gracilaria vermiculophylla is an invasive organism—Unless of course you live in East Asia, where it is considered to originate from. Outside of East Asia however, human activities have carried this organism far and wide. Of those activities, the trading of Japanese oysters to the rest of the world is believed to play the biggest role in transporting Gracilaria to new environments.

Above all, what makes Gracilaria so remarkable is that it can thrive in many different types of conditions all over the world. For example, Gracilaria can easily be found along the coastline right here in Charleston, but the climate in Charleston is very different from its native environment in Japan. Gracilaria’s remarkable ability to adapt to its environment makes it an interesting organism to study.

gracGracilaria vermiculophylla found along Grice Beach, Charleston, South Carolina. Photo Credit: Melanie Herrera.

Given that, I will be researching Gracilaria with Dr. Erik Sotka at Grice Marine Laboratory. My research will attempt to uncover some of the reasons why Gracilaria is able to thrive in so many different environments, and what allows other invasive species to thrive in varying conditions. Past research has found that heat shock proteins (Hsps) may play a role in Gracilaria’s ability to survive. Hsps are molecules found inside most living organisms that regulate the functions of the cells and thus keep the organism alive during high stress events (extreme temperatures, or in the case of marine organisms, extremely high or salinity levels). In response to that, researchers have recently developed what are known as inhibitors. Inhibitors are tools that halt the functions of Heat Shock Proteins. We believe that giving inhibitors to Gracilaria can halt the functions of their Hsps, and we can use that information to gain insight about the stress tolerance of Gracilaria, and ultimately other marine organisms. To do this, I will be harvesting lots of Gracilaria form Charleston Harbor, giving them inhibitors, and subjecting them to extreme temperatures and salinity levels to see how they respond. Additionally, we hope that the data we generate can inform predictions about the health of other marine organisms as ocean temperatures rise due to climate change.

I want to dedicate some words of appreciation Dr. Erik Sotka, Benjamin Flanagan, Dr. Bob Podolsky, Grice Marine lab The College of Charleston, and the NSF for this wonderful opportunity.

Works Cited:

Sørensen, J. G., Kristensen, T. N. and Loeschcke, V. (2003). The evolutionary and ecological role of heat shock proteins. Ecol. Lett. 6, 1025–1037.

Queitsch, C., Sangster, T. a and Lindquist, S. (2002). Hsp90 as a capacitor of phenotypic variation. Nature 417, 618–24.

Krueger-Hadfield, S. A., Kollars, N. M., Strand, A. E., Byers, J. E., Shainker, S. J., Terada, R., Greig, T. W., Hammann, M., Murray, D. C., Weinberger, F., et al. (2017). Genetic identification of source and likely vector of a widespread marine invader. Ecol. Evol.

 

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Playing with Plutei

Hailey Conrad, Rutgers University

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Me! Photo Credit: Kady Palmer

Ocean acidification is known as climate change’s evil twin. When the pH of ocean water drops, carbonate ions in the water form carbonic acid instead of calcium carbonate. Calcium carbonate is the form of calcium that marine animals that have calcium-based skeletons (like us!) and shells use to build their bones and shells. Having smaller and weaker skeletons or shells impacts their ability to survive. However, some individuals within certain species or populations of species have genes that make them more resistant to ocean acidification. If these individuals are able to pass on these genes to their offspring, then the species has the ability to evolve in response to ocean acidification instead of going extinct. This summer I’m working with Dr. Bob Podolsky in College of Charleston’s Grice Marine Field Station to study the extent to which ocean acidification affects Atlantic purple sea urchins, Arbacia punctulata. We are specifically trying to see if any individuals within a population from Woods Hole, Massachusetts, have any heritable genetic resistance to the negative impacts of ocean acidification. We hypothesize that there will be genetic resistance given that the northern Atlantic coast naturally has lower levels of saturated calcium carbonate, so a population that has evolved to live in that type of environment should have some resistance to lower calcium carbonate levels already (Wang et al 2013). We’re using a basic cross breeding technique to rear Arbacia punctulata larvae to their plutei stage, when they have four main body rods. At this stage they look less like sea urchins than they do like Sputnik!

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A sea urchin pluteus larvae with four body rods

Then, we will look to see if any of the male parents consistently produce male offspring that are more resistant to ocean acidification.  If males like these exist within this population, then the species has the capacity to evolve in response to ocean acidification, instead of going extinct! This is a very big deal, and could potentially be very hopeful. Even if we don’t get the results that we are hoping for, the results of this research could inform policy and management decisions.

Literature Cited:

Wang, Z. A., Wanninkhof, R., Cai, W., Byrne, R. H., Hu, X., Peng, T., & Huang, W. (2013). The marine inorganic carbon system along the Gulf of Mexico and Atlantic coasts of the United States: Insights from a transregional coastal carbon study. Limnology and Oceanography, 58(1), 325-342. doi:10.4319/lo.2013.58.1.0325

Thank you to the National Science Foundation and College of Charleston’s Grice Marine Laboratory for funding my project. And, special thanks to Dr. Bob Podolsky for being a wonderful and supportive mentor!

 

Hiding in plain sight

Brian Wuertz, Warren Wilson College

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How much do we really know about all the chemicals that we are exposed to every day? Do we even know when we come into contact with them? How much do we know about what is in homogenized milk, soda, stool softeners, baby formula, and personal care products such as eyeliner? The answer may be “not enough” for one compound found in all of those products, dioctyl sodium sulfosuccinate, or DOSS. DOSS has recently been identified by my mentor, Dr. Spyropoulos and his Ph.D. student, Alexis Temkin, as a probable obesogen. Obesogens are a class of compounds that promote obesity by interfering with the body’s hormone signalling pathways related to energy use, fat cell regulation, and inflammation. These pathways are especially important in the developing fetus, where hormone signals influence development and may have long lasting effects on the health of the child after birth (Holder 2016).

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I am working on a High Performance Liquid Chromatography  (HPLC) system, in the early stages of developing a method to measure the amount of DOSS in cell extracts. (More to come in future posts!)

We are especially concerned with regards to the developing fetus and child because stool softeners containing DOSS are are commonly taken by pregnant women. Approximately 35% of over 20,000 women who gave birth at MUSC in recent years reported taking a stool softener containing DOSS during their pregnancy. I am working to help understand the biochemical pathways DOSS may follow to affect changes in the  developing fetus through a mother’s exposure to DOSS. I am also working on a method to measure the amount of DOSS in cells so that we can learn where in the body DOSS goes and how much of it there actually is.

You might be wondering how this fits into the theme of marine organism health at this point since all I have talked about is human health and a compound found in products we put in our bodies, DOSS. A red flag was raised about DOSS through research on COREXIT, one of the agents used to clean up the Deepwater Horizon oil spill. Over 40 million gallons of COREXIT was dumped into the ocean as a part of the cleanup effort and DOSS is one of the major components (Temkin 2016).  DOSS was flagged as a potential human health hazard because of the research done on marine environmental degradation. It amazes me how a perhaps seemingly unrelated topic can end up having human health implications. I am excited to keep working on this puzzle to learn more about DOSS and how it interacts with the systems in our bodies!

Funding for this REU program is generously provided by the National Science Foundation and hosted by the College of Charleston. Dr Demetri Spyropoulos at the Medical University of South Carolina is graciously hosting my research project and providing mentorship.

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Sources:

Holder, B., Jones, T., Sancho Shimizu, V., Rice, T.F., Donaldson, B., Bouqueau, M., Forbes, K., and Kampmann, B. (2016). Macrophage Exosomes Induce Placental Inflammatory Cytokines: A Novel Mode of Maternal–Placental Messaging. Traffic 17, 168–178.
Temkin, A.M., Bowers, R.R., Magaletta, M.E., Holshouser, S., Maggi, A., Ciana, P., Guillette, L.J., Bowden, J.A., Kucklick, J.R., Baatz, J.E., et al. (2016). Effects of Crude Oil/Dispersant Mixture and Dispersant Components on PPARγ Activity in Vitro and in Vivo: Identification of Dioctyl Sodium Sulfosuccinate (DOSS; CAS #577-11-7) as a Probable Obesogen. Environ Health Perspect 124, 112–119.

 

 

 

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.

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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.

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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/.