Japan’s Ogasawara Islands: Expedition to Collect Cetacean Sounds and Images

The trek to the Ogasawara Islands is not exactly straightforward and presents a number of challenges. To reach this isolated yet highly important place for cetaceans, you must first travel to Tokyo, one of the largest cities in the world. Once you get there, you must then figure out how to get around while navigating the culture and especially the signs in the Japanese capital.

Once passengers have settled into their cabins and the departure time arrives, the ferry sets out from the port, embarking on a 1,000-kilometre southbound journey that will last 24 hours. This crossing takes us from the busy industrialized port of Tokyo to the remote and pristine Ogasawara Islands. Along the way, swells and stiff winds translate into bouts of seasickness, while albatrosses, shearwaters, and the occasional back of a whale entertain those brave enough to stand on the deck with their eyes peeled.

Whale-watching paradise

After a full day on the water and a few sporadic cetacean sightings, the ferry finally arrives at the largest island in the archipelago, Chichijima. It is in this small, tropical and sunny town that the adventure of documenting these animals takes on its full meaning. Indeed, the island’s main village is replete with souvenirs, signs and statues depicting these giants of the sea. There’s also an exhibition on cetaceans, not to mention a multitude of companies and individuals offering offshore whale-watching tours. Throughout all these activities, the local Ogasawara Whale Watching Association manages and regulates offshore adventures, in addition to conducting research on these animals. Without a doubt, cetaceans are a major component of the archipelago’s identity.

I was lucky enough to spend two days on the water and enjoy a number of awesome observations while trying to make sense of the explanations given by the interpretive guides in Japanese. Some of the most exceptional sightings were the groups of competing humpbacks, where males repeatedly slapped the surface with their fins, possibly to gain access to a female. I also observed a pod of spinner dolphins resting in one of the bays, far from the ocean swell. Furthermore, during my stay there, I managed to make about ten underwater sound recordings that I was eager to listen to and analyze once I returned home.

Departure from the archipelago and sound processing

The return trip was an adventure in itself. An adventure that involved leaving the small tropical archipelago of Ogasawara to travel to the St. Lawrence Valley, which was still covered in a beautiful blanket of snow. Back home, it’s time to eagerly review the audio files recorded in the Pacific. The sound recordings notably allow me to make two interesting observations about cetaceans. The first is that nearly all the files include the captivating songs of humpback whales as a backdrop. These sound sequences produced by males during the breeding season can be heard all around the archipelago, which is frequented for this very reason. The second, is that spinner dolphins are very silent when they are resting. Indeed, the recordings contained no echolocation clicks and very few whistles or other social vocalizations, especially considering the number of individuals observed. This information is corroborated by the scientific literature, which states that this species primarily relies on its vision to navigate when it is at rest. It is with these observations, a treasure trove of material for training and other projects, as well as some wonderful memories that the Ogasawara adventure comes to an end.

Whale-watching jargon in Japanese

鯨 – Kujira – Whale
ザトウクジラ – Zatou Kujira – Humpback whale
マッコウクジラ – Makkō Kujira – Sperm whale
イルカ – Iruka – Dolphin
ハシナガイルカ – Hashinaga Iruka – Spinner dolphin
シロイルカ – Shiro Iruka – Beluga (literally, “white dolphin”)
ブロー – Burō – Spout
海 – Umi – Sea
船 – Fune – Boat