Offshore Surveys
The survey in Ogasawara is conducted using three methods such as photo-identification, song recording, and epidermal sample collection. This data is compared with ID photos, songs, and genetic material identified in the waters around Japan and overseas. We then can obtain clues to the existence or non-existence of exchanges between seas, as well as the relationship and frequency of these exchanges. In addition, we have been able to compare ID photos and songs with genetic material identified in different parts of the world. Our research vessels will approach the whales from the rear in a non-threatening manner, photograph the patterns on the ventral side of the tail for individual identification and record their songs. After a whale’s violent behavior, its epidermis floats on the surface of the ocean, and we collect this epidermis to analyze the whale’s genes. These surveys provide information on whale age, growth, sex, social structure, gestation and calving intervals, group interactions, abundance, and marine pollutants. This information will provide important basic data for understanding the current status of humpback whales in the entire North Pacific.
Data organization (Matching)
The data obtained by each method is entered into a database on our computers and organized. However, before that, the most time-consuming part is organizing or “matching” the ID photos. First, we look for the same whales within the same season, and then we look for them among past photos. In this process, we also use photos of dorsal fins and enter detailed records into the database, such as which whale was in which group with what other whales present.
