Mote Marine REU Program Application

Transcription

1 Mote Marine REU Program Application The Marine Microbiology of Elliptical Star Corals Principle Investigator: Mia DeMarco Mentor: Dr. Kim Beach Ritchie Mote Marine Laboratory and Aquarium 1600 Ken Thompson Parkway Sarasota, FL 34236

2 Project Aims: The Marine Microbiology REU program at the Mote Marine Laboratory studies the role of microbes in corals. The first objective of this project will require me to assess the microbial components of healthy and diseased corals. Then, I will pinpoint which microbial factors help increase disease resistance and resilience in corals. In addition, I plan to study how microbes are transferred between corals. These three objectives will call for the use of field assessments as well as microbiological and molecular techniques. While field assessments will warrant the use of scuba or snorkeling equipment, microbiological and molecular techniques will require the utilization of microbial culturing, DNA sequencing, and polymerase chain reaction (PCR) technology. Background: The study of marine microbiology in corals largely concerns the host-microbe relationship between corals and zooxanthellae. Zooxanthellae are photosynthetic algae that aid corals by bringing in nutrition and removing waste products. Meanwhile, coral tissue provides zooxanthellae with a place to live. Unfortunately, if corals are exposed to environmental stressors such as pollutants, high temperatures, or harmful pathogens, they begin to expel zooxanthellae through a process called bleaching (Lesser, 2007). Bleached corals are susceptible to diseases and starvation. This project focuses on how harmful pathogens can incite the bleaching process. Previous studies have demonstrated that certain microbes can create distinct bleaching bands and patterns in Dichocoenia stokesi and Montipora corals (Bourne, 2005). These bleaching patterns may suggest that microbes are transmitted from coral base to tip because the

3 bands typically first appear at the coral base. The microbes in question include a variety of bacteria and viruses. These microbes typically live on the surface mucus layer of corals (Rosenberg, 2007). While some bacteria have been shown to produce antibiotics, other microbes, such as those from the bacterial genus Sphingomonas, have been shown to lead to bleaching in corals in the Florida Reef Tract (Richardson, 1998). However, only a few microbes have been identified as being beneficial or harmful to coral health. In addition, little research has been done to investigate the transference of microbes between corals. Significance: The global coral population has declined by 30% in the last 30 years due to the effects of coral bleaching (Rosenberg, 2007). At this rate, Coral reefs may disappear from the face of the Earth by the end of the century. This would be devastating not only to organisms living in these ecosystems, but also to fisheries and communities that financially depend on reefs (Bellwood, 2004). Coral reefs also serve as natural barriers that help protect shorelines and coastal communities from powerful storms and currents (Bellwood, 2004). Therefore, it is imperative to conserve coral reefs for future generations. This REU project will address several topics neglected in previous studies on the microbiology of coral reefs such as the transmission of microbes and the factors that promote disease resilience in corals. The results will help determine why some corals are more resistant to disease than others and could offer insight on how to prevent the spread of harmful microbes. Methods: This project lacks a budget since it is an REU, not a SURF. In addition, I am not certain

4 what the timeline breakdown will be. However, I do know that this project will allow me to work under Dr. Kim Beach Ritchie at the Mote Marine Laboratory in Sarasota, Florida. Her research focuses on the host-microbe interactions in corals and the role of beneficial microbes in marine organisms. I aim to compare the bacterial communities from the mucus of healthy Dichocoenia stokesi corals (elliptical star corals) to the mucus of bleached Dichocoenia stokesi corals for this project. After identifying the microbes present in both sample types, I will observe how they are transferred between corals. Coral mucus samples will either be collected from elliptical star corals at the lab or in the field. While mucus from corals in the lab can easily be collected in test tubes, mucus from corals in the Florida Reef Tract will also require the use of scuba or snorkeling equipment. I plan to ask my mentor how to collect the mucus properly without harming the coral. Although I am not certain how many mucus samples will need to be collected for this project, I do know that the microbe communities from the mucus samples will need to be grown using microbial culturing in order to have enough samples of microbes to analyze and compare. I plan to produce 50 microbe community samples from the mucus of healthy Dichocoenia stokesi and 50 samples from the mucus of bleaching Dichocoenia stokesi. DNA sequencing and PCR technology will be used to identify and compare microbes from the mucus of healthy corals to microbes from the mucus of bleaching corals. I hypothesize that the samples that are more resilient to disease will possess specific beneficial microbes that other samples from corals of the same species will not. The samples will then be exposed to one another in order to track the transference of microbes using DNA sequencing and PCR technology. Preliminary Experience:

5 I first learned about the Mote Marine Laboratory and the field of marine microbiology through my participation in the TIP Marine Biology Field Studies Program through Duke University. I also became familiar with some equipment used in water quality testing, such as a coliform bacteria test kit, through this program. This equipment was used to test the water quality of the Sarasota Bay by studying the microbes present in the water. The results of these tests were synthesized and compared to other nearby bodies of water in a mock lab report. I have furthered my interest in the marine sciences since my time spent with the Duke TIP program by writing an article about the effects of anthropogenic activities on coral reefs. Also, I have a basic understanding of PCR technology and DNA sequencing after taking AP Biology in high school. I plan to become more familiar with these techniques before the REU project by taking a class in molecular biology and genetics next semester. In addition to my experience in the marine sciences, I was trained to work in a professional lab through an internship with GE Healthcare in Troy, New York. Although the lab work for this internship dealt with materials science, it familiarized me with various lab safety protocols and procedures. The internship also helped develop my presentation skills because I was required to present my research findings through an oral presentation and a research paper. Conclusion and Dissemination: This REU project will help me gain a better understanding of the roles that microbes play in elliptical star corals. My results will help identify new microbes that are either detrimental to coral health or could be used to help rehabilitate diseased corals. Also, my results could shed some light on the transfer of microbes between corals. I will be given the opportunity to present my results in a research paper and at a poster presentation at the end of this project. Most

6 importantly, this REU project will provide me with the experience needed to design and apply for a SURF in order to further my interest in the field of marine microbiology in the future. Word Count: 1191 Scholarships and Honors: Honors Carolina Program Carolina Research Scholars Program AP Scholar with Honor Award New York State Regents Scholarship for Academic Excellence Works Cited: Bellwood, D. R., et al. "Confronting the Coral Reef Crisis." Nature (2004): ProQuest. Web. 12 Nov Bourne, David G. Microbiological assessment of a disease outbreak on corals from Magnetic Island (Great Barrier Reef, Australia). Coral Reefs (2005): Springer. Web. 12 Nov Lesser, Michael P., et al. Are infectious diseases really killing corals? Alternative interpretations of the experimental and ecological data. Journal of Experimental Marine Biology and Ecology (2007): ScienceDirect. Web. 12 Nov Richardson, Laurie L., et al. Florida s mystery coral-killer identified. Nature 392. (1998): Web. 12 Nov Rosenberg, Eugene, et al. The role of microorganisms in coral health, disease, and evolution. Nature Reviews Microbiology 5. (2007): Web. 12 Nov 2015.