Bill, Dan and I comprise the "second wave" of our UAB/USF research team, now steaming aboard the National Science Foundation research vessel (RV) Laurence Gould towards Palmer Station. Once we arrive we will join the rest of the research team led by Chuck, who have been working at the station since early February. Aboard our ship are two outstanding and enthusiastic researchers that are studying aspects of the biology of marine mammals. Let me share with you a bit about what they are to on this trip south.
Mark McDonald and his wife, Dinny Faulkenberg, are the chief scientist team on board our research cruise. They are here to conduct three different projects related to the study of whales in Antarctica. First and foremost are their investigations of the sounds (acoustics) that whales use to communicate with one another. By listening with sensitive acoustic instruments they can record the sounds that whales make in their natural habitat. One of the things they can do with the recorded sounds is called an "acoustic census", which means they essentially use the sounds that they record to estimate the abundance of the whales.
This is done routinely in Sperm Whales, where both males and females make clicking patterns that can be recorded across distances of 10 km in females and up to 30 km in males! Sperm whales are "chatty", with approximately 90% of the whales making clicking noises at any given time. Thus, they lend themselves well to acoustic census techniques. Analyzing their clicking patterns can also yield important information about whether they are organized into distinctive groups (almost like different races in human terms). Mark believes that acoustic measurements used to census Sperm Whales will soon become commonplace in other species of whales.
Mark and Dinny are also deeply involved in studying the songs of Blue Whales, the largest animal on our planet. In Blue Whales, the males do all the singing and do so mostly in the winter during the breeding season. There are nine different types of songs that can be used to distinguish different sub-groups of Blue Whales. Genetic evidence supports the hypothesis that these nine different song groups are indeed separate from one another. Using song recordings and genetics to reveal that Blue Whales are divided into different sub-groups is very important in how we manage their populations.
For example, Blue Whales once numbered in the hundreds of thousands in Antarctica. But heavy hunting in the 1920's reduced the populations by over 200,000 whales, and even though they were protected in the 1960's, today there are only about 1000 individuals left. It turns out that the sub-group of Blue Whales in the seas of Antarctica is distinct from all the other groups, including a nearby sub-group in Chilean waters off South America. Thus, if the numbers of Blue Whales in Chile were to increase, this should not be taken as a sign of the recovery of Antarctic populations, as it is likely these sub-populations do not interbreed. This is very important information to have in hand. The other two projects that Mark and Dinny are conducting on this cruise are designed to contribute information to an international pool of scientists studying whale population dynamics. This is done using both photographic and biopsy information. Photographic identification information is captured by whale biologists equipped with cameras with powerful telephoto lens. I often see Dinny on the bridge of our ship with just such a camera in her hand! Typically the photographs are taken from small zodiac boats that do not endanger the whales.
Each type of whale has its own distinguishing features. If Dinny were following a Humpback Whale she would take pictures of the underside of the fluke, whereas if she was close to a pod of Killer Whales she would focus either on the white saddle patch just behind the dorsal fin or the white eye patch. These photographs can be used to identify and thus get to know specific individuals. Biopsy is conducted by collecting a small skin sample from a whale. Mark uses a cross bow to shoot an arrow that removes a very small piece of outer skin tissue for later genetic analysis. This information, like photographs, can be used to identify specific individuals as well as better understand the genetics of different populations of whales.
Mark and Dinny are clearly making a substantial contribution to our understanding of the population biology of whales here in Antarctica. What a stroke of good fortune to have discovered them aboard the very ship that is taking us to Palmer Station!