Extreme 2004: Exploring the Deep Frontier Search

Home Mission and Crew Seafloor Geology Creature Features High-Tech Tools

Shellie Bench

Extreme Crew

Where are you from, and what is your role in Extreme 2004?

I am a graduate student in the lab of Dr. K. Eric Wommack at the University of Delaware. This will be the second time I have participated in an Extreme hydrothermal vent cruise. During the 2001 Extreme cruise, before I began graduate school, I worked on a different project and was responsible for sequencing the DNA of the bacterial symbiont of the hydrothermal tube worm (Riftia pachyptila). It was on that cruise that I met Dr. Wommack and decided to go to the University of Delaware for graduate school. During the 2004 cruise, I will be working closely with the postdoctoral researcher in our lab, Shannon Williamson, to study viruses that are found naturally in hydro-thermal vent environments. We will be investigating the viral communities that inhabit diffuse-flow hydrothermal vent fluid and the interactions that exist between viruses and host cells in hydrothermal environments.

What questions are you trying to answer and why?

There are several questions that I plan to address regarding hydrothermal vent viral communities including (1) Do vent viral communities differ from viral communities indigenous to other (less extreme) marine environments; morphologically, genetically, or both? (2) Is viral infection an important mechanism of bacterial mortality in hydrothermal vent environments, and (3) Is lysogeny (a type of virus-host interaction whereby a stable coexistence is established between the virus and host cell upon integration of the viral genome into the genetic material of the host) an important alternative to lytic infection in vent environments?

Why is this research important? What are the benefits?

It is now known that viruses are the most abundant organisms in the marine environment as a whole, outnumbering all other forms of life by at least an order of magnitude. Viruses are believed to play a critical role in shaping marine microbial ecosystems by influencing bacterial production and diversity, ultimately impacting the flow of carbon and other nutrients in the marine environment. Viruses that enter into lytic and lysogenic interactions with host cells have the potential to influence microbial communities by mediating the transfer of genes from one host cell to another by a mechanism called transduction. Additionally, the establishment of a lysogenic interaction between a virus and host cell is known to impart many benefits to the host through the expression of virus-encoded genes (conversion) such as increased cellular fitness, homoimmunity (the resistance to infection by similar strains of viruses), antibiotic resistance, and toxin production. Therefore, it's also possible that viruses may enhance the survival of their hosts in hostile, extreme environments either through gene transfer or conversion.

What's your background and what lured you into marine science/education?

All of my early education was received in southern California public schools through attending community college at LA Pierce College. I transferred to UC Davis in northern California to complete my bachelor's degree in genetics. Throughout my education, one of my largest concerns was the health of our planet and the incredible damage that has been done over the last few hundred years to many of Earth's ecosystems. Because the majority (over two-thirds) of the planet is covered with water, the oceans are critical as global environmental regulators. That is what inspired me to become involved in marine research. I am convinced that the hope of reversing the negative direction in which our planet is headed lies in the marine realm. At the very bottom of marine food webs are the single-celled microbes that are responsible for feeding all of the larger organisms in the oceans. More importantly, these microbes are also responsible for the majority of biochemical interactions that occur at the boundaries of oceans with land and air. This includes critical reactions such as converting atmospheric CO2 into sugars through photosynthesis, thereby lowering the global amount of this greenhouse gas. Also, it is primarily microbes that are capable of breaking down crude oil and other toxic substances, such as pesticides, into less harmful forms. These are some of the reasons that I chose to study marine microbes. Even though marine mammals and fish are much more charismatic, it's the microbes that are really running the ecosystem. While this is obvious to researchers now, the importance of bacteria in the oceans is a relatively recent discovery (in the last 25 years!). Because of this, the microbial community is also one of the least understood areas in marine science and, therefore, one of the most exciting areas of research, with new discoveries being published nearly every month.

Contact Us

University of Delaware
Copyright University of Delaware, November 2004