Small Steps to Save the Sea Turtles

Kelly Townsend, Elmhurst College

IMG_1416

Turtle trawl on the R/V Lady Lisa. Photograph authorized by NMFS Section 10(A)(1)(a) permit 19621.

The problem: Do you like sea turtles? As for me, I have fallen in love with these cute creatures who occupy parts of the ocean. Seeing them pop their heads up or glide through the water always amazes me, but many species are endangered. A lot of effort has gone into saving them since sea turtles play an important role in the marine ecosystem. The marine ecosystem makes up a part of our world that is deeply loved but also threatened. Sea turtles help marine ecosystems function by limiting the amount of seagrass beds and sponges through consumption (McClenachan et al., 2006). Therefore, sea turtles presence in the environmental community is key to ecosystem restoration where their numbers have dropped and seagrass disease has been able to spread and coral overgrowth has increased. In addition, sea turtles also play an important role in ecotourism. Places like Costa Rica, United States, and Australia use sea turtles as a source of income by promoting tourism in areas where they live or nest, offering turtle walks, and selling souvenirs (Campbell, 2003). Since sea turtles act as an important resource for humans, there has been much effort into rehabilitating injured sea turtles and researching them in order to determine better prognostic indicators and courses of treatment. Sea turtles are important to us environmentally and economically, so saving them from going extinct requires the most reliable research and data possible to make that happen

 

IMG_0287

Turtle nesting beach located in Tortuguero, Costa Rica.

RNA and plasma proteins are both potential indicators for overall organismal health, but they can degrade quickly if not properly stored. Plasma protein concentrations in sea turtles can help wildlife veterinarians diagnose a disease and create a proper treatment plan (Gicking et al., 2004). Therefore, measuring plasma proteins in archived samples can indicate when or if a . particular disease developed in sea turtles. In addition, RNA concentrations and quality are good indicators of general health. High ratios of RNA/DNA has shown indications of increased cellular protein synthesis along with increased growth potential which means the sea turtle is growing properly (Vieira et al., 2014). However, in order to use archived samples to accurately track health indicators such as plasma proteins and RNA, it is vital to know if storage conditions allowed degradation of these molecules.

IMG_1438

Whole blood tubes used for RNA analysis.

This study aims to investigate RNA and plasma protein stability at different temperature treatments over periods of time. Samples will be maintained in favorable conditions along with unfavorable conditions to analyze the difference between the qualities. By knowing what happens on a molecular level to blood when storage conditions go wrong, we hope to eliminate the use of low quality samples used in research. Freezers malfunction, people forget to put samples away, and blood may not be put in the proper place so the results of this study will become a reference to those researchers who experience these tragedies.

I would like to thank Dr. Jennifer Lynch, Jennifer Trevillian, and Jennifer Ness with the National Institute of Standards and Technology for being my supportive and awesome mentors. This project was made possible by the samples collected by Dr. Michael Arendt and the funding from the National Science Foundation (NSF DBI-1757899) supported by the Fort Johnson REU program.

References:

Campbell L. 2003. Contemporary culture, use, and conservation of sea turtles. In: Lutz PL, Musick JA, and Wyneken J (Eds). The biology of sea turtles, volume 2. Boca Raton, FL:   CRC Press.

Gicking JC, Foley AM, Harr KE, Raskin RE, Jacobson E. 2004. Plasma protein electrophoresis of the atlantic loggerhead sea turtle, Caretta caretta. Herpetological Medicine and Surgery 14:13-18.

McClenachan L, Jackson JBC, Newman MJH. 2006. Conservation implications of historic sea turtle nesting beach loss. Front Ecol Environ 4:290-296.

Vieira S, Martins S, Hawkes LA, Marco A, Teodosio MA. 2014. Biochemical indices and life traits of loggerhead turtles (Caretta caretta) from cape verde islands. PLoS ONE 9:e112181.

Advertisements

Bacteria in the Ocean? That Eat Iron??

Lauren Rodgers, Rutgers University

Version 2The problem: Have you ever asked yourself, what is iron? It is an element? A rock? Some weird orange-ish substance? Is it the tool that you use to get the wrinkles out of clothes? And what does iron even do? Does it just sit there? Does anything eat it? Can we make things out of it? Iron is one of the most abundant elements on earth, yet not many people know much about the important role it plays in our lives.

Iron is more than just an element, or something found within a rock. It’s a nutrient, something necessary for the growth and metabolism of almost every living organism on Earth (Hedrich & Johnson, 2011). In the ocean, iron is found in two different forms, ferrous iron or Fe(II), which is soluble in water, and ferric iron or Fe(III), which is insoluble in water (Hedrich & Johnson, 2011). Because ferrous iron is soluble it is the form of iron that can be used by most organisms in the water (Hedrich & Johnson, 2011). This ferrous iron, however, is limited in the ocean despite its abundance in the Earth’s crust. In fact, Fe(II) is present only in incredibly small concentrations, making it a major limiting factor of growth for all of the plants and algae in the ocean. This is important because these plants and algae serve as the base of many food chains, so if there is a limitation on the growth of these organisms, it affects every other organism throughout the food chain. Though iron is an extremely important nutrient for many living organisms, it is still not well understood. One of the least understood aspects is how iron specifically cycles through different marine environments. Does it ever change form? Does anything add iron to the ocean? Does anything take iron out of the ocean? These questions bring us to Zetaproteobacteria.

Zetaproteobacteria is a recently discovered class of iron-oxidizing microbes. This just means that the bacteria eat iron in the form of Fe(II) and produce Fe(III) as a waste product (Emerson et al., 2007; Chiu et al., 2017). In fact, these waste products can take on the form of hollow tubes, also called tubular sheaths, or twisted stalks that you can see under the microscope!

 

Zetaproteobacteria were initially described in 2007 near hydrothermal vents, utilizing the large concentrations of Fe(II) that were present in the fluid that spewed from the vents (Emerson et al., 2007).

Iron Mat

Iron mat composed of Zetaproteobacteria on a lava rock near the submarine Loihi volcano. (A. Malahoff, Hawaii, Loihi Volcano, July 1988)

How do Zetaproteobacteria relate to the cycling of iron? 

Zetaproteobacteria, with their role in eating iron and transforming it from its soluble Fe(II) state into its insoluble Fe(III) form may have an important role in the cycling of iron through the environment, functioning as an important source of iron removal.

Since their discovery, Zetaproteobacteria have also been observed in many other habitats, including coastal estuarine habitats with lower levels of iron, similar to that of Charleston, SC. (Laufer et al., 2017; Chiu et al., 2017). Our study will try to identify if these Zetaproteobacteria are present in the muddy soils around Charleston, as well as measure the levels of Fe(II) and Fe(III) in the rivers where these bacteria may be found.

 

This slideshow requires JavaScript.

Hopefully, through the study of the distribution of Zetaproteobacteria across the globe, including the chemical characteristics of the different environments that they inhabit, we may get a clearer picture of how iron cycles in aquatic environments and the role that these Zetaproteobacteria play.


I would like to thank my mentor, Dr. Heather Fullerton, for guiding me through this research. I would also like to thank the National Science Foundation for funding this research as well as the College of Charleston and Grice Marine Lab for their support.


References 

Chiu, B. K., Kato, S., McAllister, S. M., Field, E. K., & Chan, C. S. (2017). Novel pelagic iron-oxidizing Zetaproteobacteria from the Chesapeake Bay oxic-anoxic transition zone. Frontiers in Microbiology, 8(JUL), 1–16. https://doi.org/10.3389/fmicb.2017.01280

Emerson, D., Rentz, J. A., Lilburn, T. G., Davis, R. E., Aldrich, H., Chan, C. S., & Moyer, C. L. (2007). A novel lineage of proteobacteria involved in formation of marine Fe-oxidizing microbial mat communities. PLoS ONE, 2(8), e667. https://doi.org/10.1371/journal.pone.0000667

Hedrich, S., Schlömann, M., & Johnson, D. B. (2011). The iron-oxidizing proteobacteria. Microbiology,157(6), 1551–1564.

Laufer, K., Nordhoff, M., Halama, M., Martinez, R. ., Obst, M., Nowak, M., … Kappler, A. (2017). Microaerophilic Fe(II)-oxidizing Zetaproteobacteriaisolated from low-Fe marine coastal sediments – physiology and characterization of their twisted stalks. Applied and Environmental Microbiology, 83(February), AEM.03118-16. https://doi.org/10.1128/AEM.03118-16

Mori, J. F., Scott, J. J., Hager, K. W., Moyer, C. L., Küsel, K., & Emerson, D. (2017). Physiological and ecological implications of an iron- or hydrogen-oxidizing member of the Zetaproteobacteria, Ghiorsea bivora, gen. nov., sp. Nov. ISME Journal, 11(11), 2624–2636. https://doi.org/10.1038/ismej.2017.132