Spring Baby Bounce for Mekong River Dolphins

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Mekong River dolphins and calf. Photo: WWF

Wildlife rangers in Cambodia have sighted 3 new Mekong River dolphin calves born during the spring breeding season this year.

Conservation group WWF, which funds research and protection of the rare dolphin in Cambodia, says the 3 new dolphin babies are a very healthy increase for the total population of just 80 Mekong dolphins.

And the WWF wildlife rangers also reported no signs of adult dolphin deaths during their spring survey of the remote pools in the Mekong where the dolphins live during the low-river season, which is often a perilous time.

The Mekong dolphins are a unique population of Irrawaddy dolphin, named for a river in Myanmar where the species is also threatened. Most Irrawaddy dolphins live near river estuaries and the sea. But the Mekong dolphins are far from the sea and most live their whole lives in the river. In Cambodia only 80 dolphins remain in a stretch of the Mekong River between Kratie province and the Laos border to the north. Another group of about 5 dolphins live in the Mekong below the Khone Falls in Laos.

WWF funds scientific research and protection programs for the Mekong dolphins from a base in Kratie.  Protection efforts include encouraging local fishermen to reduce the use of set gill-nets, which can entangle dolphins attracted to the netted fish.

Source: WWF

Mekong: a river rising | The Guardian

 

The fate of 70 million people rests on what happens to the Mekong river. With world leaders meeting in Paris for crucial UN climate talks, John Vidal journeys down south-east Asia’s vast waterway – a place that encapsulates some of the dilemmas they must solve. He meets people struggling to deal with the impacts of climate change as well as the ecological havoc created by giant dams, deforestation, coastal erosion and fast-growing cities

John Vidal’s first stop along the river is the tiny country of Laos. Fifty years ago, Laos began to build a series of giant dams. It was the first chance the country had to generate the electricity and money needed to emerge from deep poverty. But is this demand for clean energy creating ecological and human havoc?

Read more at Mekong: a river rising / The Guardian

Siamese Mud Carp and Hydroelectric Dams in the Mekong River Basin (Various Studies)

From: Potential Effects of Hydroelectric Dam Development in the Mekong River Basin on the Migration of Siamese Mud Carp (Henicorhynchus siamensis and H. lobatus) Elucidated by Otolith Microchemistry by Michio Fukushima, Tuantong Jutagate, Chaiwut Grudpan, Pisit Phomikong, Seiichi Nohara, 6 August 2014

quote1Of the vast multitude of fish species in the Mekong River, two closely-related species, Henicorhynchus siamensis and H. lobatus, are of special concern given the rapid rate of hydropower development. Inhabiting the Mekong and Chao Phraya basins (H. siamensis) and the Mekong basin (H. lobatus), these two small-sized cyprinids, collectively referred to as Siamese mud carp, are the most abundant and most economically important fish in the middle and lower Mekong basin. They are harvested in huge numbers, especially in and around Tonle Sap Lake in Cambodia and the Khone Falls area in southern Laos. These species account for 43% and over 50% of the total catch in these areas, respectively, with an overall basin-wide catch being >12% for the two species combined.

quote1The Siamese mud carp populations in the Mekong, or at least some of them, are known to perform long-distance migrations. However, what is known about their migrations is severely limited. In Thailand and Laos, the species undertake upstream migration in the early rainy season above the Khone Falls, whereas in Cambodia, this species migrate upstream at the onset of the dry season below the waterfalls. The latter migrants possibly originate from the Tonle Sap Lake, first descending the Tonle Sap River and then ascending the Mekong mainstream toward and even past the Khone Falls . Spawning takes place in tributaries or floodplains during the wet season, with a peak in May-June. Eggs and larvae are carried to nursery habitats on the floodplain by the water current. At the beginning of the dry season, juveniles move out of the floodplains with the receding water and seek dry season refuge habitats such as deep pools in the Mekong mainstream.


From: Population subdivision in Siamese mud carp Henicorhynchus siamensis in the Mekong River basin: implications for management. Adamson EA1, Hurwood DA, Baker AM, Mather PB. 2009

quote1A molecular approach was employed to investigate stock structure in Siamese mud carp Henicorhynchus siamensis populations collected from 14 sites across mainland south-east Asia, with the major focus being the lower Mekong River basin. Spatial analysis of a mitochondrial DNA fragment (ATPase 6 and 8) identified four stocks in the Mekong River basin that were all significantly differentiated from a population in the nearby Khlong River, Thailand. In the Mekong River basin, populations in northern Lao People’s Democratic Republic and northern Thailand represent two independent stocks, and samples from Thai tributaries group with those from adjacent Mekong sites above the Khone Falls to form a third stock. All sites below the Khone Falls constituted a single vast stock that includes Cambodia and the Mekong Delta in Vietnam. While H. siamensis is considered currently to undertake extensive annual migrations across the Mekong River basin, the data presented here suggest that natural gene flow may occur over much more restricted geographical scales within the basin, and hence populations may need to be managed at finer spatial scales than at the whole-of-drainage-basin level.

From: ‘The migration pattern of Trey Riel, Henicorhynchus siamensis, in the Mekong mainstream’ Chan Sokheng, 2000?

quote1Below the Khone Falls, H. siamensis migrates upstream from November to February, whereas above the Khone Falls, it migrates upstream from March to September. It migrates in response to changing water levels. As floodwaters recede H. siamensis migrates from the flooded areas back to main river channels, e.g. the Mekong mainstream. Several fishers below the Khone Falls reported that the peak period of upstream migration for H. siamensis occurs one week before the full moon. Above the Khone Falls, migrations appear to be less influenced by the lunar phase. Some fishers along the stretch from Kratie to the Khone Falls in Cambodia were able to determine the speed of migration based on the time it takes for the fish to move between two villages along the river. They estimated the speed at 16 km per day… Below the Khone Falls, H. siamensis migrates downstream from May to September when the water levels start to rise. This corresponds with the peak time for observations of eggs in the fish, i.e. the peak spawning period is believed to occur between May to June.

quote1Migration is usually linked to changes in the water levels. When water levels start to rise during the flooding season, fish migrate from the Mekong mainstream to canals and flooded areas. Near the end of flooding season fish migrate back to the larger rivers. In the Mekong mainstream upstream migrations occur from November to February and downstream migrations from May to September (below Khone falls). The patterns of migration described below the Khone Falls differ from observations made in northern Lao and Thailand, where migrations take place from November to February. This could indicate that a different sub-population is involved in that section of the river. It should be noted that fishers catch this species all year round.

2015-08-15 16_08_52-www.mekonginfo.org_assets_midocs_0001336-biota-the-migration-pattern-of-trey-rie

 

From: ‘Life history of the riverine cyprinid Henicorhynchus siamensis (Sauvage, 1881) in a small reservoir’ by A. Suvarnaraksha, S. Lek, S. Lek-Ang and T. Jutagate. Journal of Applied Ichthyology, August, 2011

quote1Fish of the genus Henicorhynchus are small migratory cyprinids and one of the most important groups in the Lower Mekong Basin and Chaophraya River basin fisheries, especially the Siamese mud carp Henicorhynchus siamensis (Sauvage, 1881). This fish is a common catch whereby in thebasin area four sub-populations were recently identified (Adamson et al., 2009). H. siamensis is also the main fish catch produced by the commercial bag-net fisheries in Tonle Sap, Cambodia, where it constitutes more than 60% of the catch and accounts for almost 10% of the total value generated (Deap et al., 1998). Moreover, H. siamensis is ranked as the top species commonly consumed by Cambodians. These advantages play a crucial role as the most important animal food for the poor (Kent, 1997) and also fulfill a role as a dietary source of vitamins and minerals (Rooset al., 2007). The importance of this fish is also acknowledged in the Cambodian currency, the ÔrielÕ, which is named after the Cambodian common name for H. siamensis of “trey riel” (Volbo-Jørgensen and Poulsen, 2000).

quote1H. siamensis is also well known for its migratory habit oflateral migration into the floodplains during the flood season and then returning to the rivers when the flood waters begin torecede (Rainboth, 1996). But it is also known not to prosper inimpoundments (Lamberts, 2001; Chheng et al., 2004), as itslife cycle depends on the river ⁄ flood regime. However, H. siamensis can successfully inhabit man-made lakes in Thailand as well as in the Lao PDR, and is among the candidates for a fish stock enhancement program to increase fish production in inland water bodies in the region (Jutagate 2009). Knowledge of the life cycles of many important SoutheastAsia freshwater fish species is still very fragmentary, especially when they inhabit an uncommon environment (Volbo-Jørgen-sen and Poulsen, 2000). Given the importance of H. siamensis to fisheries in many parts of major Southeast Asian rivers, this study aimed to investigate the key facets of the H. siamensis life history (Froese et al., 2000), i.e. reproduction, feeding and growth. A goal was to see whether this small cyprinid could flourish and support a small-scale artisanal fishery in a reservoir and to evaluate its potential as a source of protein and micronutrients as well as income for the local people in the vicinity of the reservoir.

Mekong Floods: The Dampening of the Wintery Suffering | International Rivers

It is the middle of winter in the Mekong region; however, throughout December, floods have brought havoc to communities along the Mekong River. From the Chiang Saen District, Chiang Rai province in Northern Thailand downward, the water level in the Mekong has risen rapidly. The flooding was most intense along the Thailand-Lao border from the Golden Triangle toward Khong Chiam, Ubonratchathani. It is unprecedented to experience such flooding in the Mekong during wintertime.

Flooding was particularly bad in Chiang Saen District around Sob Kok, the delta plain in the Kok River where it meets the Mekong. In just one morning, the flooding damaged a large plantation owned by local villagers. Water from the Mekong River suddenly spilled over the banks causing levels of water tens of centimeters high to flood the area; corn, tobacco, bean and other vegetables vanished in the blink of an eye.

On December 19, The Vientiane Times reported that construction on the Xayaburi Dam was halted as the Mekong River rose, flooding the site. The Xayaburi Power Company – owner of the US$3.5 billion hydropower project – announced that “work on the dam’s spillway had to stop when water flowed over the temporary barriers and lower parts of the area were submerged.”

via Mekong Floods: The Dampening of the Wintery Suffering | International Rivers.

Arirang News : Korea vows financial support for development along Mekong River [VIDEO]

Korea has pledged additional support for infrastructure and economic development projects along the Mekong River in Southeast Asia.

Finance ministers from Korea and Laos signed a memorandum of understanding in the Laotian capital of Vientiane on Friday that calls on Korea to deliver around 200 million U.S. dollars in development assistance as part of the Economic Development Cooperation Fund.

The two countries plan to build embankments along the Mekong River for the construction of roads and bridges and seek out new business projects using the Hangang River in Seoul as a model.

via Arirang News :: Korea vows financial support for development along Mekong River.

Laos holds Mekong livelihoods in its hands | Bangkok Post: news

The Mekong River Commission\’s MRC Joint Committee, comprised of representatives from Thailand, Laos, Vietnam and Cambodia, will hold a special meeting next week in Vientiane to discuss the controversial Don Sahong Dam, the second dam proposed on the lower Mekong mainstream. This is an important opportunity for Laos to heed calls from its neighbours in Cambodia, Vietnam and Thailand, who have requested that the decision over whether or not to build the Don Sahong Dam is made regionally, rather than unilaterally. In September, Laos attempted to simply notify the MRC and member countries of its intention to build the Don Sahong Dam, eschewing regional discussion and sidestepping its responsibility to submit the project for \”prior consultation\”.The consultation process allows the four Mekong countries to discuss and evaluate the impacts of the Don Sahong Dam, to seek agreement about the project\’s future.

via Laos holds Mekong livelihoods in its hands | Bangkok Post: news.

Japan mulls to boost medical exports to 5 Mekong countries – Xinhua | English.news.cn

TOKYO, Nov. 25 (Xinhua) — Japan is mulling to boost its medical-related exports to five Mekong-bound countries in Southeast Asia by setting up a task force involving public and private sectors later this week, according to local media on Monday.

The task force aims at accelerating Japan\’s exports on its advanced medical technologies such as facilities and medical insurance system to Cambodia, Thailand, Myanmar, Vietnam and Laos, reported Japan\’s Kyodo News.

The move is a part of Japanese Prime Minister Shinzo Abe\’s growth strategy and the country plans to sign a memorandum of understanding on expanding medical cooperation with the Mekong countries in a summit commemorating the 40th anniversary of diplomatic ties between Japan and the Association of Southeast Asian Nations (ASEAN) in Tokyo next month, said the report, citing government officials.

via Japan mulls to boost medical exports to 5 Mekong countries – Xinhua | English.news.cn.