Eric Collins XC Seminar


In this seminar, Dr. Collins introduced results from the recent Arctic expedition by discussing different properties of Oceans. Mainly focusing on the movement of Arctic waters, sea ice and chemical properties. He entertained the idea that sea ice is very diverse and that water samples (including what microbes can found in water samples) are heavily dependent on the chemical properties of ice. There was also a description of the different layers of water and how the layers originated. Comparisons of how the flow of water looked like in the past and what it looks like now was mentioned. One example is how oceans used to be freshwater and why that impacts the modern Arctic. There was also an exploration of how density, temperature, salinity and nutrient density are related in seawater.

The discussion of microbes in seawater began with a query about how distinct layers of microbes in the ocean came to be and how they are correlated with water movements. Dr. Collins also brought up the idea that melting ice could cause microbial extinctions. Microbes are also essential for nutrient cycling in the Arctic. Primarily, the most conducive location for microbial growth is the boundary between the warm waters and cold winter waters since it is the area that allows for the simplest nutrient access. Results showed there are significant differences in what microbes were found in different regions of seawater. Dr. Collins finished his seminar with another project he has been working on-mapping how microbes differ by only 10 miles in seawater. He said that there have been issues with this project since sequencing produces mass amounts of data but he created a cool globe-like map for representation.


The seminar was concentrated on ideas about oceanography and I thought it was interesting to learn about this topic as it is not something I have spent much time considering before. I liked that Dr. Collins tied in a lot of the chemical basis of why ocean water moves the way it does. I also enjoyed that he made an effort to include interesting facts and why his seminar is relevant. In class we have talked extensively about ubiquity of microbes. The diversity of microbes in sea ice is an example of that ubiquity. There is also the idea that conditions more conducive to certain microbes selects for those microbes, which is something that we have talked about in class. For example, temperature and salinity surely impact what kinds of microbes can inhabit a region.

This seminar has piqued my interest in the microbes of  sea ice. The idea was not discussed in depth and I would like to know more details about it. For example, what specific biochemistry allows microbes to exist in the conditions? Also, how relevant is the microbial extinction that Dr. Collins mentioned?