The FOODBANCS Project
FOODBANCS stands for FOOD for the Benthic ANtarctic Continental Shelf and is a collaborative study run by Dr. Dave DeMaster and Dr. Carrie Thomas here at NCSU and Dr. Craig Smith and University of Hawai'i. In terms of oceanography, the continental shelf is the ocean floor region between the 'coast' and the 'deep sea'. This gently sloping intermediate region is associated worldwide with high levels of biological activity. In Antarctica, because the continent is holding such a heavy ice load, it has actually caused a depression in the earth's crust, making it one of the deepest continental shelves in the world, average about 600m depth compared with a global average of about 133m. Despite this depth the benthic region (contains animals living on the seafloor) still maintains a high level of biological activity, relying heavily on organic material raining down from the surface (phytoplankton).
The western Antarctic Penininsula has been experiencing extreme rapid warming in the last 100 years. This warming has influenced the timing and retreat of sea ice, and it is believed to be the most important factor in the timing, succession, and abundance of different phytoplankton species that bloom during the short non-winter season (about 4 months). This is likely to effect animals that live in the seabed, since they rely on the plankton for food. Photosynthetic phytoplankton convert CO2 to O2, when it sinks it removes carbon from the atmospheric system, and sediment feeders 'bury' or 'remove' the carbon from the ocean system into the sediment. A change in food source type and availability, which accumulates in the sediment year round (at least at the warmer stations) as a "foodbank" could have an important effect on trophic structure and elemental cycling, with potential impacts on the global scale.
We're doing a number of experiments and in order to get it all to Chile and ready for the boat there is a lot of prep work. Rebecca has been growing and harvesting algae for feeding experiments to see what the animals like to eat best. She is growing diatoms (Thalassiosira), prymnesiophytes (Phaeocystis) and cryptophytes (Cryptomonas) which must all be frozen at -20 degrees celsius and hand carried on the 24 hour transit to the southern tip of Chile.
I'm also interested in phytoplankton, but my concern is with its packaging and the fate it endures on the long trip to the seabed (either through feeding by zooplankton like krill, or microbial degradation that occurs as it sinks). I'm looking at the different pigments phytoplankton use to harness energy from the sun and seeing how they degrade to give some clue as to how much the plankton is being chewed on before it reaches the seabed. I will be looking at chlorophyll a using a fluorometer onboard the ship and (as pictured above) I have to have a lot of fresh, pure chlorophyll a to calibrate the fluorometer and it too must make the long trip to Chile without thawing. Here's hoping our journey is without delay!
I am also looking at diatoms in the seabed and will be sampling the kasten core to do that.
Here is what the Kasten core looks like going over the side:
Me sampling the kasten core for porewater:
In this picture, the syringes are 3 cm wide and spaced about 10 cm apart. To sample diatoms on the scale that we would like to resolve I will be sampling EVERY centimeter. My syringes must also be 1 cm, which is very small. In order to do us the syringes to sample the sediment you must cut off the tip and smooth down each tiny syringe (we ocean scientists often have to mutilate tools from other sciences to make them fit our needs). Since the kasten core usually comes out anywhere between 1-2m, thats about 100-200 samples. So for me, that means lathing and smoothing tips for 100 syringes. Talk about tedious.
Rest assured, all things will be completed and packed. We leave Saturday afternoon for Chile and I will update the blog as I go, so follow along.. things are about to get really exciting!
