Sperm Whale Seismic Study (SWSS) Chronicle 6

Special Reports from the SWSS Scientists

June 17, 2005
Prepared by Dr. Lars Bejder

Research Associate and SWSS Visual Team Coordinator
Biology Department
Dalhousie University
Halifax, Nova Scotia

The ability to see sperm whales at the sea surface, even at great distances from the ship, provides information which enables the tagging team to get into position. Housed on the flying bridge at the top of the R/V Gyre, the visual team keeps watch for sperm whales from sunrise to sunset (Figure 1). The visual team works in two different ways: searching and tracking. When searching, the visual observers scan the seas around the Gyre for sperm whales. When whales are found, the acoustic and visual teams work together to track the animals and provide information on their location to the tag boats.

Sperm whales have a very distinctive blow which angles forward at 45 degrees making identification relatively easy. Using big-eye binoculars (Figure 2), a visual observer can spot a sperm whale blow at 12 kilometers distance on a clear, calm day. Once a whale is sighted, the distance to the whale is measured and location information is entered into a database. When the tagging boats are out, these data are radioed to them and they begin their approach to the animals for tagging.

In addition to sperm whales, the visual team identifies and records other marine life (e.g. sea turtles, dolphins, etc.) (Figure 3). These observations provide important documentation of animal distribution in the northern Gulf of Mexico. Working in hot, humid conditions the visual team plays an important role in the continued success of the Sperm Whale Seismic Study (SWSS).