Scientist Laura Gemery shares her story of "Life on the Back Deck"During this cruise, the chief scientist, Dr. Lee Cooper, has planned 40 collection stops, called stations. Collection is carried out 24 hours a day, so there are two working groups, each taking 12-hour shifts. I'm working the 11:30 am to 11:30 pm shift, so we suited up for our first stop on Friday. It was exciting to walk out on deck for the first time ready for sampling. The sun was still up, and for as far as you can see in every direction, a carpet of ice extends to the horizon.
All suited up on the first day of sampling.
When working on deck, it's required that we wear steel-toed boots, a helmet and a mustang suit, which is a blaze orange one-size that is also a PFD incase of an accidental fall overboard. It is pretty well insulated, but you still need to layer up underneath.
It was 15 below zero, and luckily, not much wind.
There are several research/collection operations taking place at each stop. Here's what takes place at each stop:
A CTD collects water at different depths in the cylinders. It also takes other measurements, too.
The first deployment is the CTD-a circular rosette of 12 niskin bottles (each holding 30 liters), which collect water from various depths to determine conductivity (the capacity of water to conduct electricity, by which we derive salinity), temperature and pressure (to derive depth). It gets deployed from a winch that slowly lowers it into the water until it reaches 5-meters from the bottom.
Notice some of the lids are open on the top as they were not needed to collect water.
Then it gets hauled back on deck where the various sensors of the machine are read and water is taken out and analyzed for biological, chemical and geochemical properties of the water. These measurements include nutrients (dissolved nitrates, urea), chlorophyll (we use a separate machine called a flourometer to measure chlorophyll), and oxygen-18. Sensors on the machine measure different characteristics of the water too, such as light, to determine where photosynthesis happens (or where algae bloom) and the cloudiness of water.
We do some of these tests onboard, but many more are done later in the year, off-ship at the scientists' respective labs.
The next deployment is an ultraviolet (UV) meter to measure how far light can reach down the water column.
Next, we deploy a bongo net that gets dragged for a short time to collect zooplankton --small animals from the ice, water column and sea floor. After bongos, comes the HAPS Corer. The corer takes a cylinder sample of the bottom about 10-15 cm deep into the sediment. We cut the cores into one-centimeter segments to wash them back in our home labs.
This corer has taken a cylinder shape sample of the bottom.
Hard work in cold weather.
Slide a plastic tray under to catch the cylinder sample.
AND then comes the really fun part for the technicians working on deck: The Van Veen Grabs
Grabbing part of the surface of the bottom. (Photo by Dr. Trites)
A winch lowers a big metal claw to the sea floor that snaps shut to collect a one-meter squared area of bottom sediment and the animals living there.
Getting ready for the next grab. (Photo by Dr. Trites)
The winch brings up the claw and we unclip a release to open it into a bucket. We spray out the inside with water to clean out the mud and make sure we get it all into the bucket so we have the full quantitive sample.
Good mud (Photo by Dr. Trites)
What's in the surface mud? (Photo by Dr. Trites)
Then we carry it to the edge of the deck, where sieves are set up. We carefully dump the heavy bucket into the sieve and wash out the bucket.
Frozen mud (Photo by Dr. Trites)
The sieve gathers the critters. (Photo by Dr. Trites)
Then in the sieve, we wash the sample as clean as we can with seawater so only the larger animals (macrofauna) are left.
It's a wet job. (Photo by Dr. Trites)
Remember, it's anywhere from -15 to -35 below zero (more with windchill). We do seven grabs per station. The sediment can be pretty thick, so it's best to use your hands to break up and stir the muck. The washing process can take about 30 minutes to 3 hours per grab. Many times the hoses freeze up or the sieve mesh closes up from ice. The deck can get pretty icy from all the water we're using as well, so we are always sure to watch our step. It was so cold today that as we washed the creatures, we MADE slush/ICE! Although we try to be careful, the spray from the hose gets on the people doing the washing, so it's not only a cold job, but a wet one too. The animals are then collected, put in containers and preserved in a chemical called formalin.
Shells and brittle stars... (Photo by Dr. Trites)
Wow!
A rare find as larger clams bury down further in the sediment.
Sunny, cold, and breezy--Love this weather. (Photo by Dr. Trites)
Water freezes quickly so we melt and sweep.
Each station's samples are labeled so when the identification happens back in the lab, we know exactly where it came from.
And that's the procedure at each stop.
Jared Weems studies the animals.
Laura Gemery identifies her samples.