Feasibility on Infrared Detection of Cetaceans for Avoiding Collision with Hydrofoil

To achieve safer navigation of high speed boats, such as the hydrofoil, without sudden collisions with large cetaceans, the authors examined the feasibility of using an infrared camera. Because any cetaceans are air-breathing animals, it is theoretically expected that they can be detected through imaging of an infrared camera. The authors examined the feasibility of detection by aiming an infrared camera at sperm whales in waters off the Chichijima Islands (27°4'N, 142°13'E), Japan. It was revealed that sperm whales could be detected stably within 200m, and the detectable cues were blow, back body and fluke tails. However, boats and waves were also detected as noise images. Waves, especially, greatly resemble the whale back bodies. Although the potential of the infrared camera was confirmed, further experiments, including ones conducted at different temperate waters, are needed to successfully use infrared cameras for the earlier finding of large cetaceans.