First Official Samples
It has been a busy few days on the RVIB Palmer. The science team collected the first set of samples for the incubation experiment. If you remember reading about the incubation prep, you know that the team cleaned numerous bottles to prepare for the experiment. The preparation of these bottles was in anticipation of our arrival at our first sampling location. The three incubation stations are located in areas that the science team is interested in sampling to learn more about the diatom/iron interaction, the diatom/bacteria interaction and other interests. The first station is located in the Drake Passage, away from the ice layers and Antarctic continent. We were able to get the samples collected just before another weather system moved into the area. This weather would have hindered our ability to collect samples. Once the samples were secured, we headed closer to the Western Antarctic Peninsula and away from the weather. Now begins the 12-day incubation period. Let's go back to the actual sampling process and then I will tell you a little bit about what happens over the 12-day incubation period.
Time To Make The Donuts...I Mean Get The Water
The process of collecting water samples for the incubation period is an all day event. We began the process at approximately 1230 and finally left the trace metal van at 2330 - 11 hours later. Why does it take so long? Well, it is because the science team requires a lot of water for their experiments. The water samples are divided between four different science teams and each team can have multiple experiments and tests that require water. So, we spent a lot of time in the trace metal van emptying Nisken bottles and distributing the seawater to all of the trace metal clean bottles. By the end of the eleven hours, 72 4L bottles, 3 10L carboys and 7 20L carboys were filled with water. This much water required four different casts of the trace metal rosette. Here's a run-down of what happens with each rosette cast:
The rosette is loaded with the 12 Nisken bottles and the cast is completed to a specified depth.
The Nisken bottles are removed from the rosette and immediately transported into the trace metal van.
Water from the Nisken bottles is emptied into three 50L carboys. A number of Nisken are emptied into one in order to homogenize (evenly mix) the samples.
These carboys are secured to the counter in the trace metal van and are used to fill the incubator bottles and a 10L carboy. Each cast has a set of bottles and a carboy - sort of like the trials of an experiment.
Each 4L bottle is rinsed a few times with the seawater and is filled 1/3 of the way with water from each carboy (again, to homogenize the water). This will fill the bottle with water from all bottles in the rosette. The science team has a great system similar to a conveyor belt to help make the process as efficient as possible. Remember, the samples should stay cold throughout this process, so the van is not heated. Throughout the process, time and bottle numbers are recorded.
Dr. Randie Bundy (back), Dr. Kristen Buck, and Dr. Dreux Chappell fill bottles using the 50L carboys. One third of the water in each bottle comes from a different carboy to help homogenize the samples. The temperature inside the trace metal van is in the 30s.
Once all the bottles for the cast are filled, each group (A - F) receives a different "spike". The "spike" is different for each bottle group. The spike can be a nutrient or combination of nutrients that the science team is interested in using in their experiments.
Once the bottles are all spiked, they are sealed and color-coded with tape. These bottles are then moved to the incubation van in the lower hold of the ship. The incubation van is set at 2C/36F and will maintain a constant temperature and 24-light period to help initial growth for the diatoms.
The incubator van is a large container that was lowered into the ship's hold prior to departure. The incubator temperature is set at 2C/36F. The incubator van holds rows of shelves specially designed for the 4L incubator bottles. There is also a light bank to maintain 24-hour light exposure.
The 4L incubation bottles are lined up and ready. Notice the different color tape and clear labeling on each bottle.
Distributing the Samples - Day 1
Now that the samples are in the incubator, the science team will begin collecting sub-samples from the bottles on predetermined days. Using a sampling grid and data table, specific bottles are removed from the incubation van and transported to the trace metal bubble. Inside the bubble, some of the seawater in the 4L bottles is removed and distributed into smaller pre-cleaned bottles. The 4L bottles are then returned to the incubator in the hold to maintain temperature and allow the diatoms to live and grow over the extent of the sampling period.
Some of the 4L incubation bottles in this picture have less water because they were sampled earlier in the day. Other bottles will be sampled on either day 3, 7, 9 or 12.
The seawater taken from the 4L incubation bottles is distributed to smaller bottles like these before they are sent to various labs aboard the ship.
This sampling process is an all-hands affair. People are needed for data collection, to run the bottles from the hold to the bubble, to stay in the bubble to distribute the water and to receive the water and begin filtering. Everyone is needed to ensure that the water is distributed quickly and minimum temperature change occurs.
Kris Gomes from URI carries two of the 4L incubator bottles using a mesh backpack. The backpacks are used because the stairwell to the hold is very steep and both hands are needed in rough seas.
There is some down time between bottle runs from the incubator van, so the team passes the time in a number of ways...
According to Dr. Kristen Buck of USF, it is tradition(and good luck) to decorate the trace metal bubble. Marine Technician (MT) Holly Martin decorates the bubble while she waits to run incubation bottles to the hold.
Sveinn Einarsoon (ODU) And Noahie Encarnacion (USF) play ping pong in the ship's hold while they wait to run bottles. The table was made by a previous crew member and can be broken down for easy storage.
Filtering - Stay Tuned
After the water is distributed to the different science teams/labs, the water will be filtered in order to collect the diatoms. Filters are set up in many of the labs on the ship, including the coolers known as Little Antarctica and Big Antarctica. In tomorrow's journal, I will tell you more about the filtering process and the different types of analyses that are conducted each day.
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