Humpback Dolphins: Sousa teuszii, S. plumbea, S. chinensis and S. sahulensis

Abstract

Humpback dolphins (genus Sousa) are medium-sized delphinids found in shallow (<30m), coastal waters of the eastern Atlantic, Indian, and western Pacific Oceans. The genus is comprised of four species: (1) Atlantic humpback (Sousa teuszii), (2) Indian Ocean humpback (S. plumbea), (3) Indo-Pacific humpback (S. chinensis), and (4) Australian humpback (S. sahulensis) dolphins. Information on the ecology, behavior and life history of all humpback dolphins remains scarce. Most study populations to date indicate that all species occur in small numbers, with most populations confirmed or suspected to be declining and threatened. Major threats affecting all species include habitat degradation and loss, and entanglement in fishing gear. Research efforts and conservation actions tailored to each species are needed to assess anthropogenic impacts, and develop strategies to eliminate or mitigate threats.