Microbiology on P18

By Alyse Larkin

Bonjour from the Ronald H. Brown!

As we pass by the Isle de Clipperton, a French territory, I am going to write a little bit about what I do here on the ship. My name is Alyse Larkin, I am a postdoctoral researcher at UC Irvine in Dr. Adam Martiny’s lab, and I am one of the few microbiologists on P18.

Traditionally, GO-SHIP cruises do not include biological measurements, so I am particularly excited to be adding microbiology to the P18 scientific roster. It is critically important to understand both how environmental variability influences the marine microbial community and, in turn, to understand how the microbial community influences biogeochemical cycling. The P18 transect will cover a large range of oceanographic provinces, and therefore represents an excellent opportunity to better characterize the function of marine microbes in the environment and their response to environmental
change.

While on the ship I will be sampling microbial DNA and particulate organic carbon, nitrogen, and phosphorus. Every latitudinal degree I take surface water from the CTD, filter it, and preserve the DNA for metagenomic analysis. Additionally, I use a huge filtration array to sample the ship’s “underway system,” which pipes surface water from the bow through the ship, for particulate organic matter.

To accomplish a thorough understanding of both microbial community and C:N:P patterns, I am usually filtering water in the ship’s bioanalytics lab for about -16- 18 hours a day. But I don’t mind! I get to see lots of beautiful sunrises and sunsets from my little window, depending on the direction the ship is pointing while on station.

Smooth Sailing

By Laura Whitmore

Smooth Sailing

After departing the first time, we got turned around due to mechanical problems. We set sail again on November 19^th. We journeyed south along the coast toward the Baja Peninsula. Before entering Mexican waters, we did a test cast. The test was used to ensure equipment was working properly and it was an opportunity for the scientists to familiarize themselves with the process. With success we continued south, our transect started at the southern tip of the Baja Peninsula, in view of Cabo San Lucas.

This region is noted for its biodiversity and abundance of wildlife – attributed to nutrient rich waters. As we continued south along  longitude -110°, we crossed the continental slope and made our way into the open basin. An interesting feature in this region is the ODZ, the “oxygen deficient zone”, which is generally in the surface 200 - 1000 m. There is a great development in the study of ODZ as “oceanic deoxygenation” becomes a discussion. It is speculated that as climate warms, oxygen in the water column will decrease; additionally, that in this region of the world the impacts of climate driven deoxygenation may already be observed. This transect, repeated a decade ago, and a decade before that will begin to fill in the answers to questions arising about this subject.

In non-scientific news: sunrises and sunsets are beautiful, the seas are calm, we’ve seen dolphins, small fish by the CTD at night, and even a small shark. Not to mention, anytime we feel a need for birds, we can walk to the bow where an assemblage of seabirds are taking the bus south relaxing on the forward mast.

Sunrise & Moon - Nov. 27

Sampling Bay - Nov. 27