While leaving the dock in Hamata there was our sixth/new dolphin species on this expedition playing with a buoy right near the coast! Even though this Indo-Pacific Humpback Dolphin (Sousa chinensis) was alone, we were able to witness its playful mood while it was having fun playing with the buoy ropes. One of the main characteristics of this species is the shape of the dorsal fin; it was an easy way for us to identify this dolphin. This hump on the back is known to get larger with age. They also have a long well-defined beak which can help identify them and usually travel in groups fewer than 10 individuals. Our concern is that we encountered it so close to the shore line near the harbor where boats were coming and going from every day. Many of the locals also said they see a group of these humpback dolphins consistently in this area. And in fact on our way back we re-sighted the same individual ten days after! This species is known to stay coastal, so some major threats to them are habitat loss, vessel strikes, and pollution. These dolphins therefore are highly vulnerable to human threats. This is another good example why boating speeds should be kept slower near coastal areas.
Catherine Fillo (HEPCA intern)