Our First Full Science Station!
Today we are going to do our first full science test station. We are still in the Gulf of Alaska and have not yet made our way through the Unimak Pass into the Bering Sea, we will do that later today. We have 6 operations planned; a CTD cast, Video Plankton Recorder (VPR) tow, Bongo net tow, Multi-net tow, tucker trawl tow and ring net tow. The Board of Lies in the Main Lab displays the list and order of operations.
The Board of Lies in the Main Lab
The first operation was the CTD. We will be repeating these operations many times over the next 39 days so I will get more in depth with the science of the equipment in later journals! A CTD is specifically a sensor that measures Conductivity, Temperature and Density. However, CTD can also refer to a very large piece of equipment that is a rosette holding Nisken bottles and many other sensors – such as a fluorometer, video microscope, etc.
Ms. Rose and the CTD rosette
The bottles are “cocked” or opened by the Marine Science Technicians (MST). The CTD will be cast – or lowered into the water over the side of the ship using a cable and an A Frame. The A frame is a part of the ship that has hydraulics that allows it to change it's position. The MST uses hand signals and a radio to communicate with the MST in the Aft Conn area. They are sitting at a control area and have computer monitors that display the sensor data as the CTD is lowered through the water. The MST analyzes the data and determines where to close the Nicken bottles on the way back to the surface. These can be pre-determined depths or areas of interest decided upon after looking at the initial data.
Notice the Nisken bottle on the left is open, the one on the right is closed
Next we deployed the VPR or Video Plankton Recorder. It takes digital images of plankton as it streams past the camera. There is also a CTD sensor on this piece of equipment.
Hoisting the Video Plankton Recorder (VPR)
After that, we deployed the Bongo nets – you may remember these from a previous journal when I attached the nets to the frame. We collected two different sample. The net with the smaller openings had a lot of phytoplankton (chlorophyll containing organisms). We are just going to look quickly through these samples. Today's tow was about practicing with the equipment and procedures.
The Bongo net hoisted from the A Frame
After lunch we deployed the multinet. This was the first time for using this net so it took quite a while to set it up and get ready to deploy it. The multinet is a piece of equipment that is made up of 4 different nets that can open and close independently from one another.
First run of the multinet
We finished with a ring net tow like we did the other day. You may have asked why the Board of Lies is called the Board of Lies...well, this morning, we had six operations planned. We made it through five operations, so the plan that was posted on the Board of Lies this morning was a “lie”.
The temperature was rather nice today and the sun was shining. It was a great day to be on deck of the USCG Healy!
The beautiful Arctic sun was shining on the Healy today!
New Vocabulary
CTD: Sensor used to measure Conductivity, Temperature and Density
Rosette: A large round piece of equipment that holds Nisken bottles and other sensors
Phytoplankton: free floating organisms capable o photosynthesis
Stayed tuned to this journal as we continue our exciting voyage on the USCG Healy!
“Live as if you were to die tomorrow. Learn as if you were to live forever.” - Mohandas Gandhi