Current position of the SSV Corwith Cramer. Click on the vessel to view position history. Use the tools, top right, to change the map style or view data layers. Dates and times use GMT (Greenwich Mean Time).
SEA Currents: SSV Corwith Cramer
July 07, 2014
In the Lab at Sea
10° 32’N by 162° 49’W
Winds NE by E, occasional rain and squalls
It is our 6th day on the ship, with 720 nautical miles behind us, we are seeing parts of the Pacific that many never will. The vastness of the sea has become apparent in the lack of human contact we have experienced since leaving Hawaii. In fact, we have yet to see another ship out here and, to my knowledge, there have been only two airplane sightings. Yet while there is very little human life out here, we (the students of S-254) are just beginning to explore the great abundance and diversity of life around the Seamans in her lab. While many of us have plenty of lab experience from our home institutions, we are enjoying the challenge of adapting to work in a lab that is constantly in motion. We have set out deployments of our hydrocast and neuston tow nightly, and have been learning to process our water and plankton samples to the (sometimes) gentle sway of the tide.
My personal favorite lab activity thus far is the one hundred counts of our plankton samples. This is our method of getting an accurate picture of the diversity of zooplankton retrieved in our tows. To collect our samples we slow the ship to a gentle 2 knots and deploy our neuston net, affectionately termed “Neustie”, and tow it for 30 minutes. This requires coordination between deck and lab watches as we handle sails to maintain our speed. When we pull up the tow we empty a pure sample from the collecting bottle, and rinse the net into another bottle to obtain the full biomass data.
After helping the deck crew with setting sails to get back up to speed, we bring our samples back to the lab where the real fun begins. We pour our pure sample through a fine mesh sieve to and pull a 1ml scoop of plankton and spread it out onto a petri dish to analyze. We use a dissecting microscope to view our sample and identify 100 organisms as we move them through our field of vision to get a picture of the composition of the tow. A simple procedure, but in an SEA lab you need to account for the constant rock of the ship bringing your eyes towards and away from your scope, and thus your sample in and out of focus at somewhat irregular intervals. The class of S-254 has already logged many hours in the lab, and just as we are becoming steadier on our sea legs, we will keep improving our SEA eyes as we approach the Phoenix Islands Protected Area.