NASA Blue Marble satellite image of the Fly River
Location of the Fly
|Country||Papua New Guinea, Indonesia|
|• location||Star Mountains, Papua New Guinea|
|Mouth||Gulf of Papua|
|Fly Delta, Papua New Guinea|
|0 ft (0 m)|
|Length||1,120 km (700 mi):10|
|Basin size||76,000 km2 (29,000 sq mi):1|
|• average||6,000 m3/s (210,000 cu ft/s)|
|• left||Strickland River|
|• right||Ok Tedi River|
The Fly River is the third longest river in the island of New Guinea, after the Sepik River and Mamberamo River with a total length of 1,060 km (660 mi) and the largest by volume of discharge in Oceania, the largest in the world without a single dam in its catchment, and overall the 25th-largest primary river in the world by discharge volume. It is located in the southwest of Papua New Guinea and Papua Province of Indonesia.  It rises in the Victor Emanuel Range arm of the Star Mountains, and crosses the south-western lowlands before flowing into the Gulf of Papua in a large delta.
The Fly-Strickland River system has a total length of 1,220 km (760 mi).
The Fly flows mostly through the Western Province of Papua New Guinea and for a small stretch, it forms the international boundary with western New Guinea. This section protrudes slightly to the west of the 141°E longitude line. To compensate for this slight gain in territory for Papua New Guinea, the border south of the Fly River is slightly east of the 141°E longitude line. As part of this deal, Indonesia has the right to use the Fly River to its mouth for navigation.
The delta of the Fly River is over 100 km wide at its entrance, but only 11 km wide at the apex upstream of Kiwai Island. The delta contains 3 main distributary channels (the Southern, Northern, and Far Northern Entrances) that branch from a common point (the “apex”). The distributary channels are 5 to 15m in depth, separated by elongate, sand-mud islands that are stabilised by lush mangrove vegetation. The islands are eroded and rebuilt rapidly in the apex area, where they have lateral migration rates of up to 150 m/a, with slower rates for the more seaward islands. Upstream from the apex the river gradually narrows to a width of 1.6 km or less. The Fly Delta exhibits a distinctive funnel shape in plan view, attesting to the fundamental role of tidal currents in shaping the Delta's geomorphology. Mean spring tidal ranges are amplified within the delta, from around 3.5m at the seaward entrance of the distributary channels, reaching a peak of about 5m at the delta apex. Seismic profiles and radiometrically dated core samples indicate that the delta is prograding seawards at an average rate of about 6 m/a  The Fly Delta is considered as a global "type case" of a tide-dominated delta and the patterns of sedimentation seen in the Delta today have been studied by sedimentary geologists as a model for interpreting the ancient rock record 
The river delta is studded with low and swampy islands covered with mangrove and nipa palm, with villages and cultivated areas on these islands. The land on both sides of the estuary is of the same character. The islands in the estuary are flat and covered with thick, fertile alluvial soil. The largest islands are Kiwai Island, Purutu Island, Wabuda Island, Aibinio Island, Mibu Island, and Domori Island. Kiwai, Wabuda and Domori are inhabited.
A list of the river delta islands is:
The inhabitants of the Fly River delta engage in agriculture and hunting. Coconut palm, breadfruit, plantain, sago palm, and sugar cane are grown.
Fly River Turtle
The Fly River turtle, also known as the Pig-Nosed turtle due to its odd nose, are notably different from other turtles due to their piglike nose. The only freshwater turtle to have flippers, the turtle is known to rarely leave water, except in dire circumstances. They are also known to be omnivores whom rarely consume meat.
The Fly was first discovered by Europeans in 1845 when Francis Blackwood, commanding the corvette HMS Fly, surveyed the western coast of the Gulf of Papua. The river was named after his ship and he proclaimed that it would be possible for a small steam-powered boat to travel up the mighty river.
In 1876, Italian explorer, Luigi D'Albertis, was the first person to successfully attempt this when he travelled 900 km into the interior of New Guinea, in his steamer, Neva. It was the furthest any European explorer had ever been into the island.
Both the Strickland and the Ok Tedi Rivers have been the source of environmental controversy due to tailings waste from the Porgera Mine and the Ok Tedi Mine, respectively. Sediment sampling and coring in the distributary channels of the Fly Delta had not detected copper concentrations significantly higher than background as of 1994. In 2008, Dr Ian Campbell, a former advisor to Ok Tedi Mining Limited, claimed that company data suggest significant portions of the Fly River floodplain are at a high risk from acid mine drainage.
- "IUCN: The Fly River Catchment - A Regional Environmental Assessment". International Union for Conservation of Nature The Department of Environment and Conservation, Papua New Guinea. 1995. Retrieved 22 November 2020.
- Canestrelli, A.; Fagherazzi, S.; Defina, A.; Lanzoni, S. (17 December 2010). "Tidal hydrodynamics and erosional power in the Fly River delta, Papua New Guinea". Journal of Geophysical Research. 115 (F4). Retrieved 22 November 2020.
- "Fragmentation and Flow Regulation of the World's Major River Systems" (PDF). Archived from the original (PDF) on 2012-03-30. Retrieved 2011-08-17.
- Frank Jacobs (March 13, 2012). "Who Bit My Border?". The New York Times.
- p.159, Barrie R. Bolton. 2009. The Fly River, Papua New Guinea: Environmental Studies in an Impacted Tropical River System. Elsevier Science. ISBN 978-0444529640.
- Harris, P.T., Baker, E.K., Cole, A.R., Short, S.A., 1993. A preliminary study of sedimentation in the tidally dominated Fly River Delta, Gulf of Papua. Continental Shelf Research 13, 441-472.
- Harris, P.T., Hughes, M.G., Baker, E.K., Dalrymple, R.W., Keene, J.B., 2004. Sediment transport in distributary channels and its export to the pro-deltaic environment in a tidally-dominated delta: Fly River, Papua New Guinea. Continental Shelf Research 24, 2431-2454.
- Dalrymple, R. W., E. K. Baker, P. T. Harris and M. G. Hughes (2003). Sedimentology and stratigraphy of a tide-dominated, foreland-basin delta (Fly River, Papua New Guinea). Tropical Deltas of Southeast Asia and Vicinity - Sedimentology, Stratigraphy, and Petroleum Geology. F. H. Sidi, H. W. Posamentier, H. Darman, D. Nummedal and P. Imbert. Tulsa, Oklahoma, SEPM Special Publication 76. 76: 147–173.
- "Blackwood, Francis Price (1809 - 1854)". Australian Dictionary of Biography.
- Lightbody, Mark; Wheeler, Tony (1985). Papua New Guinea: a travel survival guide (3 ed.). Lonely Planet. p. 172. ISBN 0-908086-59-8.
- Harris, P.T., 2001. Environmental Management of Torres Strait: a Marine Geologist’s Perspective, in: Gostin, V.A. (Ed.), Gondwana to Greenhouse: environmental geoscience - an Australian perspective. Geological Society of Australia Special Publication, Adelaide, pp. 317-328.
- "PNG warned of environmental mining disaster". ABC News. Australian Broadcasting Corporation. 2008-09-06. Retrieved 2008-01-06.