Observing the behavior of meso- and bathypelagic animals, especially highly motile ones, has been and continues to be a major obstacle to the advancement of studies on their ecology. In the mid-1980s, technological advances in the design of small video systems and microprocessors enabled researchers to build instruments that could be carried by free-ranging marine mammals and turtles to record their behavior and environment at depth. During the past five years, these instruments have become increasingly sophisticated, although their size still limits their current use to animals weighing more than 50 kg.
The most recent video system and data logger developed in our laboratory will record simultaneously the behavior, swimming performance, physiological variables, sound, three-dimensional movements, and environment of animals at depths to 2,000 m. The camera records the immediate environment in front of the animal at distances ranging from one meter (using the camera's near-infrared light source under low-light conditions) to tens of meters in front of the animal depending on available light levels and water clarity. To date we have attached the video system and data logger to free-ranging elephant seals, a leatherback sea turtle, and Weddell seals.
In the future, continuing development and miniaturization of digital video cameras and microprocessors will enable us to deploy video systems with data loggers on smaller marine vertebrates and invertebrates. Using marine animals as platforms for video and data recording holds great promise as a cost-effective means of studying their behavior and ecology in the deep sea.
Last updated: December 19, 2000