Ayeyawady River Corridor

Description

The Ayeyawady River Corridor (ARC) covers a 400 km stretch of one of the last major undammed rivers in Asia. Tributaries originating high in Myanmar’s northern mountains flow south before joining northeast of Myitkyina to form the Ayeyawady River. The river basin lies almost entirely within Myanmar and covers nearly 60% of its land surface. Above the city of Mandalay until Bhamo, the river is home to the globally VU Irrawaddy Dolphin. The CR sub-population of Irrawaddy Dolphin in this river is famous for its cooperative fishing behavior with humans. The ARC provides habitat for these dolphins, as well as for other wildlife including the White-bellied Heron and several species of globally threatened turtle.  In total, the corridor covers 400 km and would protect 90,000 hectares of river and riparian habitat.

ARC (Lower: Mingun to Kyauk Maung segment) (N22 19 11, E96 0 2)

The southernmost segment is the only section that is formally protected. This section is coincident with the Irrawaddy Dolphin Protected Area (PA). This PA was established in 2005 after surveys by the Department of Fisheries (DOF) and WCS estimated that at least 59 dolphins were present (Tun 2005; WCS 2013). The area is managed by DOF but it has yet to be formally gazetted. The PA is 72 km in length and runs from Mingun to Kyauk Myaung. It covers 32,600 hectares and is 10 km at its widest. Surveys have found 35 fish species. Of these, the Bago Labeo (Labeo boga), Aspidoparia (Aspidoparia morar), and Gangetic mystus (Mystus cavasius) are the most common (Tun 2004; Ng 2013).

ARC (Middle: Moda Section,Takaung to Shwegu segment) (N24 1 18, E96 21 48)

The middle part would extend 160 km from 9.5 km south of Takaung to 4.8 km north of Shwegu, and cover 37,200 hectares. The area provides habitat for the Irrawaddy Dolphin and many fish species (Tun 2005). Although little detailed data is available on this segment, it likely has similar species composition to the lower and upper segments.

ARC (Upper: Shwegu to Bhamo segment) (N24 10 55, E97 7 21)

The uppermost part would start 9 km to the north of the middle section and continue to the town of Bhamo, 41 km to the north, covering 19,900 hectares. Its northern extent would end at a narrow point in the river that is believed to be impassable to dolphins. Birds found here include the CR White-bellied Heron and VU Lesser Adjutant.

Justification of Outstanding Universal Value

The ARC includes a globally unique sub-population of the Irrawaddy Dolphin renowned for its co-operative behavior with local fishers.  The ARC also provides important habitat for globally threatened birds and turtles, and could provide habitat for the re-introduction of a Myanmar-endemic turtle species. The ARC provides habitat vital to the survival of this sub-population, as well as for a range of other freshwater species including the CR White-bellied Heron, which may have a global population as low as 250. All three sections may provide habitat for the globally threatened and Myanmar-endemic turtles and for the future re-introduction of the CR Northern River Terrapin and the VU Burmese Eyed Turtle. Each section of the ARC overlap with an Important Bird Area, and the lower section has been identified as a potential Ramsar site.

The Ayeyawady River has a central role in Myanmar history and culture, serving as a source of life-giving water and sediments that have formed the basis of successive civilizations that now form Myanmar, cultural value to its outstanding natural features.  Specifically, cooperative human-dolphin fishing could meet cultural criterion (vi).

The ARC’s three component parts are necessary in order to protect wide ranging and migratory species such as the Irrawaddy Dolphin, fish, and waterbirds, which all range along these sections of river. While the existing Irrawaddy Dolphin PA is an important first step, the dolphin’s range extends another 330 km to the north, which is encompassed in these sites.  Detailed data on dolphin migration within the corridor is not available, but it appears that the cetaceans move between sections of the river following fish migration and been seen in the area between the lower and middle sections of the ARC property (Tun 2005; IUCN 2013). The Ayeyawady River supports significant human population and economic activities, which can be managed between the sections in buffer zones and with river-wide laws such as those governing mining and legal fishing gear.  The three components also contain important habitat for waterbirds and turtles.

Criterion (x): The ARC contains habitat essential to the survival of a CR sub-population of the Irrawaddy Dolphin, which may currently contain as few as 59 individuals (Smith 2004).  These dolphins make up one of three CR freshwater sub-populations that are completely isolated from marine populations (Jefferson et al. 2008).  The estimated 20 dolphins remaining in the southernmost segment of the ARC are globally outstanding for their communication and cooperation with fishermen.

The ARC also provides some of the best habitat of undisturbed sandbanks for the future reintroduction of the Northern River Terrapin from assurance colonies. The Northern River Terrapin was historically common in the Ayeyawady, but now is considered extinct in the wild in Myanmar.  The Burmese Eyed Turtle, which is endemic to Myanmar, may also be present in the area and could be reintroduced if it has been extirpated. Past records indicate that it was present as far north as Mandalay and the Shweli River, but its current status in this area is unknown (Platt et al. 2006). The northernmost segment of the serial site is an IBA and contains waterbirds and several other species of interest.  Globally threatened species present include (Myanmar Biodiversity 2012):

Mammals: VU: Irrawaddy Dolphin (Orcaella brevirostris) (sub-population CR)

Reptiles: CR: Burmese Narrow-headed Softshell Turtle (Chitra vandijki); EN: Burmese Peacock Softshell Turtle (Nilssonia Formosa)

Birds: CR: White-bellied Heron (Ardea insignis); VU: Lesser Adjutant (Leptoptilos javanicus); >1% of global population: Ruddy Shelduck (Tadorna ferruginea), Cotton Pygmy-goose (Nettapus coromandelianus), Bar-headed Goose (Anser indicus)

Potential reintroductions: CR: Northern River Terrapin (Batagur baska); VU: Burmese Eyed Turtle (Morenia ocellata).

Statements of authenticity and/or integrity

The ARC’s three sections extend over the Irrawaddy Dolphin’s known range, including area for migration along the river. All three sections share a warm-water fish species assemblage distinct from cold water areas further upstream.  Ayeyawady is currently undammed, giving it a level of integrity that is increasingly rare for large rivers in Asia. The proposed Myitsone Dam project and a complex of upstream dams were put on hold in 2011 but future dam construction may impact the integrity of the ARC. Irrawaddy Dolphin populations may be decreasing, primarily due to electric fishing, including with electric gill nets, and drowning in fishing nets (Smith 2004). Mercury and arsenic contamination is a concern, with 180 gold mines impacting portions of the corridor in 2002. Mining has been banned within 90 m of the riverbank since 2012, greatly reducing mercury concentrations (Tun 2005). Though there are no longer gold mining boats in the Irrawaddy Dolphin PA, small-scale mining on the banks persists as a threat.  All turtle species are threatened by hunting for export to China. Northern River Terrapin reintroductions will require sandy riverbanks undisturbed by seasonal cultivation and secure from egg collection.

Upstream of Bhamo, a fourth potential section of the ARC stretches from Sinbo up to just south of Myitkyina.  This stretch of river is an IBA where seven additional globally significant waterbird congregations (>1% of the global population) are found.  This Sinbo-Myitkyina section contains an assemblage of cold water fish that is distinct from the warm water fish assemblage found in the three other ARC sections downstream.

Comparison with other similar properties

The most similar site in the region is the middle stretches of the Mekong River north of Stung Treng, Cambodia.  Stung Treng was established as a Ramsar site in 1999.  It extends for 40 km along the Mekong River and covers 14,600 ha of braided channels and alluvial islands. It provides valuable habitat for the CR Giant Mekong Catfish (Pangasianodon gigas) and White-shouldered Ibis (Pseudibis davisoni). In addition, a CR sub-population of the Irrawaddy Dolphin is found here consisting of 114-152 individuals. Their upstream migration is limited by Khone Falls in Lao PDR. A proposed Mekong mainstream dam in Stung Treng would destroy their habitat.  In comparison, the ARC is much longer and is less threatened by dams.

Another similar site is on the Mahakam River in East Kalimantan, Indonesia. This river also hosts a CR sub-population of the Irrawaddy Dolphin. Fewer than 80 dolphins live in a section of the river that stretches from 180 km to 600 km upstream of the river’s mouth. The Mahakam does not have the other globally threatened freshwater species found in the Ayeyawady.