On a molecular level...

How well coordinated is this science research cruise?

Dr. Bill Cochlan, RTC-SFSU, SciChi

Our Chief Scientist and lead Principal Investigator, Dr. Bill Cochlan (RTC-SFSU) has put together an amazing team of scientists, students, and teachers with one overarching goal of analyzing the effects of oceanic acidification on the lipid (fats/oils) synthesis in the ocean's keystone organism, phytoplankton. As the foundation to the food web, phytoplankton, particularly diatoms, are extremely important to the quantity and quality of the entire web, leading to us the consumer. I will go more in-depth in a future post on Dr. Cochlan and his work, but until then, I will continue to focus on each of the specific experiments on board and the unique groups that delve into their particular research.

Joselynn Wallace, URI

Joselynn Wallace, URI and
Heather Richard, RTC-SFSU taking a break

Joselynn Wallace and Laura Filliger traveled from the University of Rhode Island to gather samples at sea that will make their way back to the labs back on the East coast. Their advisor, Dr. Bethany Jenkins, in their Ph.D. program, Integrative and Evolutionary Biology (IEB), was unable to attend this cruise because she had just spent 65 days at sea earlier this year. So, she called on her two top students: Joselynn in her third year, Laura in her first.

Laura Filliger, URI

Joselynn and Laura, fun on the fantail

Joselynn is the veteran. This is her third stint at sea, researching phytoplankton and comparing data from each new area of the globe--it's research that matches her expertise: microbiology.  Laura is the newby to this floating laboratory but is learning fast from Joselynn and seems right at home on the R/V Melville. Laura's learning curve is steep because she's sailing solo in November--three weeks to Antarctica! Together, they run their lab with precision and great care, all while keeping a positive attitude and adding to the "vibe" of this cohesive unit on board.

Their work is unique on board. They are the only ones researching the phytoplankton on a molecular level. All of the other focused experiments are physiological, which makes sense as a lab at sea. But, this goes to show the genius vision of the Chief Scientist, Dr. Cochlan; each of the labs are selected to shed new light on the ultimate mission of the research and the reason that it was funded. Like the layers of an onion, each separate experiment reveals more from another angle, allowing the scientists on board to compare data from different methods. This check and balance system pinpoints possible errors earlier as well as shedding new light, helping us to better understand what is exactly happening to the phytoplankton as the ocean's acidity level rises in nutrient-rich but iron impoverished areas--the direction of the global seas will one day be at our current rate.

left to right:
Hannah Glover, NOAA-PMEL
 Kit Angeloff, NOAA-PMEL
Laura Filliger, URI

These "gene jockeys," as Dr. Cochlan quips, are a valuable piece to the research puzzle. On a molecular level, Joselynn and Laura are researching a phytoplankton genus, Thalassiosira, that is found all over the earth's oceans from the sub-tropical to the polar regions and are "key players in all of those systems" (Wallace). By focusing on this universal genus with different species all over the world, they are able to compare the DNA and RNA from each of these communities. They use a filtering system similar to the one that Denis and I are using to extract chlorophyll to gather the biomass; then, they have the coolest step to any experiment on board. Literally. They use a dewar of liquid nitrogen, -321°F, -196°C, to flash freeze these samples, locking their genetic makeup until they are ready to extract the DNA and RNA in the lab back in Rhode Island.

Dewar of liquid nitrogen, LN2

According to these "gene jockeys," DNA differs from RNA in a similar way as a football team has starters and those on the bench, ready to come in and play when the conditions are right. The DNA is the whole team; the RNA is the actual players on the field. I think that they realized that a football analogy for me would be the best way to explain a very complex process; and it worked. Basically, DNA is all of the possible options, while RNA is that which is actually activated--the gene expression that is metabolically active. By comparing the RNA from different members of the same genus, they can see on a molecular level how the organism has adapted over generations to survive in different environments. Our focus here is on those that have been starved of sufficient iron (i.e. iron stressed). From Joselynn and Laura's current work and the past work of other molecular scientists, the RNA of coastal species is different than those in open ocean. Coastal regions are nutrient-rich; open ocean's have limited nutrients. The open-ocean species have adapted to become "iron scavengers," grabbing this necessary component for photosynthesis and nitrogen fixation from every source possible. Coastal species would not survive in the open waters. Diatoms' ability to scavenge iron from different sources may change with seawater pH.  Since they are the foundation of the marine food web, this information is critical for understanding how the ocean might respond to climate change and elevated carbon dioxide. All of this research is dependent on each other. I guess I could say that the chemistry of the science crew is just as important as the chemistry of the ocean. Joselynn, Laura, and the University of Rhode Island are integral part of this chemistry of thought and discovery. They will be able to compare their findings to those of the other teams onboard.

*I will be writing about Brian Bill, lead research associate for NOAA, and his taxonomy work of phytoplankton in an upcoming post with another on the complimentary work of Dr. Charles Trick and his team, using different methods to draw conclusions from the data independently before comparing.