Student Connection

April 20, 2000 The TOWNSEND CROMWELL is now west of the Hawaiian Islands conducting oceanographic sampling that is used to support fisheries research.

The title of this cruise is:  Highly Migratory Species Oceanography. This fancy name means that we are studying the environmental conditions which are important for understanding some fish stocks such as tuna and swordfish which range far and wide in their search for food. We are conducting Conductivity, Temperature, Depth Profiles (CTD's)  along a line or transect that goes by two buoys; one a weather buoy and the other an oceanographic mooring buoy named "Bigeye" after bigeye tuna. The Bigeye buoy is attached to a cable that goes down to an anchor on the sea floor. There are oceanographic sensors at specific points along the cable. The buoy has a transmitter that sends position data to satellites periodically so that researchers know that it is still there and working. Recently it has been malfunctioning and we were asked to check out the transmitter that is attached to the structure on the buoy. The swells were about 8 to 10 feet with about three feet of wind chop. Sea conditions don't show up well in two dimensional photographs. Unfortunately we didn't have the right parts to fix the transmitter so we put it back on because intermittent operation is better than none.

We are also fishing for bigeye tuna so that we can tag them with archival tags. These tags are surgically implanted in the fish and record and store information on light, temperature, and depth.  Once the tag is returned by a fisherman to our laboratory, the data can be analyzed to estimate movement patterns, behavior habits, and oceanographic preferences of the fish.  

Other Reports from This Cruise:

April 28

May 07

Last modified April 20,  2000