Dr. Tom Weingartner and the BEST project are all about the water. During this trip int the Bering Sea, CTD casts into the hundreds have been conducted.
I thought the best way to share some more insight on the CTD is to hear from an expert. Here is contributing blogger Ben Jokinen, our Senior Marine Tech:
The CTD system is the underwater equivalent of an oceanographic Swiss Army knife…. uhmmm, except it doesn’t fit in your pocket. It does however allow scientists to add and remove sensors depending on what aspects of the water column they are most interested in analyzing. The CTD, which stands for Conductivity, Temperature, and Density or depth, is the bread-and-butter of oceanographic research these days. You will find instrument packages like this on every research ship on the ocean.
A variety of sensors on the CTD allow scientists to view all of the different aspects of the water it is sampling – temperature, salinity, oxygen levels, water clarity, the amount of light that penetrates to different depths, an idea of how productive the water is from a nutrient level, as well as the height above the bottom so the unit doesn’t touch down and get damaged. All of this information is sent up the cable which is about a mile long! The cable is spooled on a winch up on the ship and is basically a really long extension cord. Power is sent down to the CTD and data is sent back up the cable in real-time, allowing scientists to view live feeds of the data as the package is lowered to the depths.
Another interesting aspect of the CTD is its ability to close sampling bottles at different depths, all from the click of a computer mouse. This means that scientists can view the data up on the ship while the CTD is lowered, find an area that interests them in the water column, and then fire a bottle to get a plug of water for further testing and examination in the lab on the ship. It is a really slick system and is used for numerous studies ranging from determining where underwater sound (density) barriers are so that Navy submarines can hide beneath them, to water quality testing which can tell us what causes harmful algae blooms that kill off commercial fishing stocks. Currently, CTD systems are being heavily used in the Gulf of Mexico to determine what harmful and unpredictable affects the oil spill disaster is having on the organisms and fisheries in that region.
Thanks for the great info Ben!
In terms of issues such as climate change and unnatural, man-made disasters and broken food chains, there are no magic bullet answers to be discovered. There is data and lots of it. The hope is that analysis of this data will lead to better decisions about fisheries and resource management and maybe even just turning off a light back home.
I have been saying it is all about the food, but now I think maybe it is all about the water. After all, without water I would have no food to cook.
Thank you to Dr. Tom Weingartner and Mr. Dave Leech and all of the science party that made this last cruise in the Point Sur’s summer sailing season a great success with a lot of fun thrown into the mix.
