26 July, 2002

We are at BC 6. That means that this is our 6th station in Barrow Canyon. Due to the depth of 2000 meters, the sloping canyon walls, and the loss of several hours to helicopter operations, the station has already taken nearly 35 hours. The multi-Haps core is the next to the last sampling procedure and we are in the process of sending the Haps core down one more time. I’m working on my journal while we wait to get back to the correct depth for a third try. We need six of the eight cores we would usually get from two trips to the bottom. However, the first try came up with two empty core tubes, and the Haps never tripped (released the coring buckets) on the second trip. It’s important to get all the required information at each station; that’s why we’re going to try again. Hopefully by tomorrow I’ll have a series of pictures of the Haps core process for you. It was a good day for pictures as the sun came out for the first time in several days. Despite the snow flurries in the air, it felt positively balmy outside. Either I’m getting used to the Arctic weather, or it is just so beautiful that I don’t notice the cold as much.

Today I spoke with Matt Cottrell and Rex Malstrom from the University of Delaware. Matt is an associate scientist in the College of Marine Studies, and he is working with David Kirchman, also from the University of Delaware. Whenever I am collecting water from the CTD cast, I always see Matt there. He collects water from five depths, three in the photic zone (remember that photo means light) and two from below the photic zone where light does not penetrate. He then splits each sample into three sub samples which he will incubate (put them into an environment where they can grow) for one, two, or three days. Since he is looking at the decrease in oxygen, he will incubate his samples in the dark so no new oxygen will be formed by any phytoplankton (plant like organisms that produce oxygen through photosynthesis) in the sample. The reason Matt is measuring the decrease in oxygen is to get an idea of the bacterial population in the depth of water from which he sampled. Bacteria are truly everywhere in our environment, and the Arctic Ocean is no exception. As a matter of fact, bacterial consumption is responsible for about one-half of the measured decrease in oxygen!

Rex’s project is related to Matt’s because Rex is trying to find out the number of bacteria and how fast they are growing. He also takes samples to be analyzed later to identify what specific kinds of bacteria he has in his samples. Bacteria are the most abundant organisms in the ocean! Measure out one milliliter of water (about 10 drops) and you would find about a million bacteria! Bacteria help to turn the carbon in organic (living) matter back to carbon dioxide (CO2) by breathing in oxygen and breathing out the CO2 as they break down their food. About 50% of the carbon that is “fixed” by phytoplankton (they take the CO2, an inorganic molecule, and turn it into a form of carbon that organisms can use) goes into the microbial loop (micro = tiny, bio = life) this way. The bacteria turn dissolved organic matter back into CO2 or into more bacteria. By measuring the number of bacteria present, Rex hopes to tell how much CO2 the bacteria produce. Rex filters his water sample through an extremely fine filter to remove the bacteria. He then treats the bacteria so they glow in the dark and he can count them under a microscope. Because very little is known about the kinds of bacteria that live in the Arctic Ocean, Rex is also collecting samples to take back for identification. Lastly, Rex is trying to determine how quickly the bacteria are growing by measuring protein synthesis (building) and DNA synthesis and calculating to get a growth rate. (My students should understand why this would be a good measure to determine growth.)

Although it took many hours to complete this station, everyone was able to get the samples they needed. At 3000 meters, our next station will be the deepest one yet. It will be another very long station. Think of people like Matt who has samples that must be incubated for one, two or three days before he can analyze them. He is very grateful that we have a bit of extra time over the next day or two. Even with the extra time, he won’t get completely caught up, but he will be closer.

Rex Malstrom is trying to find out the number of bacteria and how fast they are growing. This will give him an idea of how much carbon dioxide the bacteria produce.

Matt Cottrell collects water samples, incubates them for 1,2,or 3 days in the dark, and analyzes each one for the decrease in oxygen. From this, he gets an idea of the size of the bacteria population in the water.

Rex Malstrom does some of his work in the chem van on the bow. This is a separate area where radioisotopes are analyzed.