Science Corner - The evolution of oceanographic equipment

By Erik Zettler, Science Coordinator

From the Challenger Reports

Nets figured prominently in oceanographic sampling methods 130 years ago during the famous Challenger expedition (1872- 1876). When SEA was founded around 100 years later, the sampling methods on Westward hadn’t changed all that much other than nets were made of nylon rather than silk. We still do a lot of basic, traditional oceanography at SEA and use a variety of net styles and mesh sizes to capture organisms in the water column. These samples in jars are some of the more valuable samples we collect and are being used by the International Census of Marine Zooplankton. Much of our data still comes back hand written on paper, but things have also changed a lot since those first SEA cruises in the 1970s, and much of the change involves computers and electronic instrumentation. While we still bring home jars and paper, each 6- week cruise also comes back with 50-60 GB of electronic data, the equivalent of 15 million typed pages. A timeline of shipboard computer resources (right) outlines these changes.

Other equipment changes include the evolution of our ability to sample the water column from Nansen bottles – Niskin bottles on the wire with reversing thermometers – Niskin bottles with CTD on the wire – carousel with Niskin bottles, CTD, fluorometers (chlorophyll and CDOM), light meter, oxygen sensor, and transmissometer.

The science working deck has changed to facilitate safe equipment handling by students and staff with bolt tie-downs and opening bulwarks for large equipment like gravity cores and nets. Better winch controls including an emergency STOP button allow the Chief Scientist to have more control of student winch operation. Good auxiliary winches with two direction variable speed and hydraulic J-frames with instrumented sheaves have replaced the original winches with fixed davits and mechanical sheave readouts. The laboratories themselves have evolved to include air conditioned cabinets for the valuable electronics, wet and dry lab areas, a clean flowing seawater system, and a data logger saving data from sensors around the vessel every minute of every cruise.

There are many programs to choose from, so SEA has to stand out and I think we do. At SEA students are actually running modern oceanographic equipment and getting an experience that few professional oceanographers or mariners will ever have: learning to sail a tall ship and collect biological, chemical, physical, and geological data on the open ocean. With all the fancy equipment, it is important to remember that the new tools are enhancements rather than replacements for good old fashioned observation, so don’t forget to get your hands wet!