We were planned to arrive at our first plankton tow site today, but the cable and winch system used for the MOCNESS nets was not working properly. This system has not been used since the ship was built and some of the kinks are being worked out. The winch was overheating and the cable return speed had to be slowed. Engineers had to contact the company that made the winch system to insure that is functioning properly. Without this system we would not be able to tow the larger plankton nets. Testing the cable system requires the ship to slow down significantly for several hours. We are now exactly one day behind. The new plan is to arrive at our first sample site at 5:00 am tomorrow. From that point forward I expect things to get active and a little hectic, not unlike stepping on a ground hornet's nest. Many of the researchers are getting anxious to get started.
Because of delays, today was rather slow. I am glad to say I am off my motion sickness meds and feel quite well, even with a cool 12 knot wind causing white caps and rolling waves to form. The deck was unpleasant and most of my day was spent inside. We used the slack time to discuss and hammer out protocol for sampling and watch schedules. I will be on a noon to midnight shift. We divided up the group into two watches to insure that enough people will be available to help with lifting the plankton nets. The project will fly three different plankton nets capable of collecting 5-8 different depth samples. Three net types will be used; 1/4 m nets, 1 m nets, and a 10m nets. These numbers describe the area of the net opening. Each sample will be collected from a different depth in the water column. We will be collecting zooplankton from the abysso, bathy, meso, and epi pelagic zones. In general zooplankton is defined as heterotrophic oceanic organisms of any size that are permanently adrift horizontally in the water column. Organisms that are highly mobile, such as squid and tuna, are not considered plankton. The scientists chosen to come on this census are experts on a variety of zooplankton. We have a veteran ostracod expert by the name of Martin Angel from England aboard, as well as several experts on copepods, true jellyfish and comb jellies, mysid shrimp, tintinnids, foraminiferans, pterophores, krill, salps, radiolarians, and deep-water fishes and fish larvae. The plan is to collect the buckets (end compartments where the plankton is concentrated) from the plankton nets and assess them for species richness. The goal is to get the big picture of what organisms are in the column. When samples first come out of the ocean, silhouette photography will be used to get a general picture of what was present and can later be used for some abundance and biomass estimates. Once this is completed each expert will collect a portion of a sample to determine specifically what species are present. There is a good chance that undescribed species may be found. Some biologists such as E.O. Wilson suggest that we have only described half of the species currently residing on earth.
Once an organism is positively identified they will be sent to the DNA bar-coding lab. The DNA lab will amplify the COI gene, which codes for a membrane bound protein involved in respiration, using PCR technology. This gene is found in all zooplankton. The middle portion of this protein lies in the phospholipid bilayer and is variable. Therefore it can be used a species marker. The bar-coding team will run the gene through a DNA sequencer. This machine will determine the nucleotide sequence for approximately 700 base pairs of the gene. This is about half the total size of the gene. Variations in the gene sequence will be used as markers for the positively identified species. Future studies should be able to use a DNA microarray built from the bar-coding to determine species absence or presence from DNA analysis alone. To anyone's knowledge in this group, this is the first time a DNA sequencer will be used aboard a ship.
My primary job will be to help in the data logging process. As nets are pulled and specimens are separated to the their prospective locations, a general record needs to be kept of what goes in and out of the water and when and where this occurs. Since so many people are involved, record keeping becomes a full time job. I will play a secondary role in helping get nets in and out of the water. I hope to learn more about the photography process scientists are using to quantify zooplankton, as well as the photography used simply for capturing the nature of these organisms, as they would appear in the water. Many of these plankton are beautiful, odd creatures that produce light; others have intricate anatomy, some so delicate that contact with the slow moving nets can rupture them. These creatures appear alien, beyond any Lucas Films artist's creativity. The deep ocean is one of the few areas of the earth still open to exploration and discovery. The microscopes, cameras, nets, pcr machines, DNA sequencer, cameras, water testing equipment, experts and myself are waiting for the sunrise tomorrow, to see what we can catch from the deep.
Daily Question: What defines the 4 pelagic zones of the ocean?
Picture 1: Repairing plankton net.
Picture 2: MOC 1/4 m preparation
Picture 3: Preparing MOC 1 m net