Historical and new records of the Irrawaddy Dolphins, Orcaella brevirostris (Owen in Gray, 1866) (Cetacea, Delphinidae) from the east coast of South Sumatra, Indonesia

Abstract

Irrawaddy Dolphin, Orcaella brevirostris (Owen in Gray, 1866), has been reported in the waters of Berbak Sembilang National Park, Indonesia, since 1990. We used interview techniques, direct observations, and secondary data from the literature to show that this dolphin occurs on the east coast of South Sumatra from October to February. An Irrawaddy Dolphin bycatch was recorded on 26 January 2021 in a gillnet. There have been historical sightings of fewer than six individuals of Irrawaddy Dolphins between 1990 and 2013 in the estuaries of Bogem, Bungin, Ngirawan, Terusan Dalam, Betet Island, Banyuasin, Lalan, and Tanjung Carat to Makarti Jaya. We map the geographic distribution of Irrawaddy Dolphin in South Sumatra.