The following outlines the project findings.
• The PIDU project has confirmed that the Australian snubfin dolphin (Orcaella heinsohni) and Australian humpback dolphin (Sousa sahulensis) occur in the Kikori Delta.
• The 2013 surveys confirmed the first record of humpback dolphins for PNG.
Dolphin Distribution and Abundance
• Surveys were extremely successful with a high number of dolphin groups sighted, primarily snubfin dolphins which are the target species.
• The high number of snubfin dolphins sighted during December 2013 and February 2015 surveys indicates that the Kikori Delta is an important regional hotspot for the species, and internationally important.
• No abundance estimates were possible for either species because it was very difficult to get close to groups to photograph them. It is estimated that no more than 200 snubfin dolphins and 100 humpback dolphins inhabit the Kikori Delta.
• No dugongs were sighted during surveys, however local villagers and fishers remained adamant that dugongs occur in the region, and excellent descriptions of dugongs were provided during interviews.
• It was interesting that locals did not appear to eat dugongs, even if they are by-caught in fishing nets. This may be as a result of local folklore in the region where dugongs are closely related to ancestors. Future studies will attempt to observe dugongs during boat surveys and collect dugong skeletal material to confirm their presence in the region.
• There were very few additional records of marine megafauna sighted during surveys. This was likely as a result of the highly turbid waters, although the region may be less productive as a result of the high turbidity and lack of coral/seagrass regions.
• There are unconfirmed records of leatherback turtles (Dermochelys coriacea) inhabiting the Kikori Delta region, reports which will continue to be followed up on subsequent surveys.
• Although not sighted alive during surveys, there appears to be a high abundance of sawfish in the Delta region, based on high numbers apparently caught in fishing gear.
Threats to Marine Megafauna in the Kikori Delta
• The primary threat to marine mammals in the Kikori Delta is accidental entanglement in fishing gear.
• An extremely worrying number of inshore dolphins are being bycaught in fishing gear, particularly Orcaella. The high mortality is undoubtedly unsustainable and should be the focus of management priorities for the Kikori region.
• At least two individuals (one snubfin and one humpback dolphin) were sighted with a pox-like lesion on their bodies. The prevalence and source of these lesions should be investigated further.
Kikori Delta Listed as an Important Marine Mammal Area by the IUCN
• As a result of research conducted by the PIDU project, the Kikori Delta has been designated as an Important Marine Mammal Area by the International Union for the Conservation of Nature.
• The means that the Kikori Delta is officially recognized as important for snubfin and humpback dolphins, and should be further managed to protect these species.