Sperm Whale Seismic Study (SWSS)

Summer Breeze Daily Reports - June 23, 2005

Position at 29.49  88 40

We left Gulfport today at 13:00 and are now heading back to the area were we observed the group of five whales four days ago.  We should reach that area sometime around midnight. Regular acoustic monitoring will start once we are deep (> 200 meters) water.

The days ashore were used to take care of some important things.  Not the least of these were Jonathan’s ears, which received appropriate medical attention as soon as we arrived in Gulfport on June 20. He felt much better yesterday when he was heading to the airport to fly back to Scotland. On the 22^nd, Raul arrived so we are a full team of seven again.

Several boat repairs were completed, and we began work on a structure to mount a directional hydrophone to a frame, which in turn is attached to the boat.  Besides the hydrophone array being towed behind the vessel and that allows us to listen while underway, we also use a hand-held directional hydrophone for tracking sperm whales at close range. Until now, this directional hydrophone, which is attached to a long pole, was deployed from the back deck. This is no problem when the boat is perfectly still and there are no currents. Clearly, this is only rarely the case, so usually, the person using this hydrophone has to use some force to keep it from drifting, all the while trying to interpret the sounds being picked up by the hydrophone. The directional hydrophone mounted to the fixed frame will eliminate that problem, and should also allow us to use the hydrophone during moderate boat speeds. First trials this evening were promising, although the drop-shaped housing for the hydrophone seems to be turning away from the boat when in the water. We will work on that issue during the coming days.