New Dinosaur makes Nine from Thailand’s North-East

Fossil bones found by farmers digging a new pond in north-east Thailand have been identified as a new species of dinosaur – the ninth dinosaur species found in this part of Thailand and the sixth found nowhere else.

New-to-science Sirindhorna khoratensis was a plant-eating iguanodontid, about 6 metres long, which lived around 120 million years ago.

The new dinosaur takes it genus name from the daughter of Thailand’s King Bhumibol, Princess Sirindhorn, an enthusiastic patron of dinosaur research. Its species name comes from Khorat, the informal name for the city of Nakhon Ratchasima about 400 kilometres north-east of Bangkok.

The fossils were uncovered in 2005 on the outskirts of the city by farmers digging a small reservoir to water their crops of corn and tapioca.

They reported the find to scientists at Nakhon Ratchasima Rajabhat University (NRRU), but the location meant that the dig teams could only collect the fossils when there were no crops in the ground, for a few months each year between 2006 and 2012.

Sirindhorna khoratensis replica at Fukui Prefectural University/Kyodo News
Sirindhorna khoratensis replica at Fukui Prefectural University/Kyodo News

Although the fossils are fragmented, most of the skull and jawbone are complete and Sirindhorna is now one of the best-known iguanodon species in Asia, say the researchers from Japan’s Fukui Prefectural University and NRRU.

Iguanodon-like dinosaurs lived in the early Cretaceous Period between 145 million and 100 million years ago, when most of Southeast Asia was covered by jungles, swamps and shallow seas.  They may have traveled in herds for protection against predators, like wild elephants today.

Masateru Shibata, a paleontologist at Fukui Prefectural University and the lead author of the research, told Kyodo News that iguanodons are thought to have colonised Asia from North America and Europe and the new find helped establish their range. Iguanodons from the early Cretaceous Period had also been found in Japan and the latest find from Thailand was “valuable as it shows iguanodons lived in a wide area of Asia,” he said.

Masateru Shibata/Kyodo News
Masateru Shibata/Kyodo News

The research has been published in the online science journal PLOS-One, and a replica of the full skeleton of the new dinosaur goes on display at the Fukui Prefectural Dinosaur Museum in central Japan on 30th January.

Sirindhorna is the ninth new species of dinosaur identified from fossils found in Thailand, all in the north-east Isan region of farmland, mountains and forests that extends from Khorat to Thailand’s Mekong River border with Laos and Cambodia.

It is the second Thai dinosaur named after Princess Sirindhorn — Phuwiangosaurus sirindhornae, a 20-metre long suaropod, was named in her honour in 1994.

North-east Thailand has emerged as a rich source of dinosaur fossils and other archaeological discoveries since the 1970s, when the first fossilized bones were found by prospectors looking for uranium in the broken scarps of Phu Wiang district, 85 kilometres west of the city of Khon Kaen and now a national park.

In 1994, the lucky find of a dinosaur bone by a monk in Kalasin province led to the discovery of a “dinosaur’s graveyard” and five new species. The discovery site has been developed into a renowned dinosaur museum and paleontology institute. Footprints from tyrannosaurs and other species have been found at several sites.

Ban Non Wat
Ban Non Wat/2korat.com

Archaeologists have also discovered important remains of the human occupation of the Middle Mekong Basin, including elaborate pottery and metalwork from grave sites at Ban Chiang and Ban Non Wat in north-east Thailand  — relics of Bronze-Age peoples who lived in the region between 3000 and 4000 years ago.

But they have warned that the region’s archaeological heritage is threatened by land development and looting that takes place before scientists can learn what’s there.

Dr Joyce White, an American archaeologist who worked on the Ban Chiang discoveries, said at a public lecture in Bangkok last year that the destruction of archaeological sites across the region would have a lasting impact on future prospects for tourism, education and the rural societies involved.

Dr White was an expert witness for the US Justice Department in a successful prosecution of a US museum that had purchased smuggled artifacts from Ban Chiang and other Thai archaeological sites. The artifacts were returned to Thailand in 2014.

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.

‘On the River of No Returns: Thailand’s Pak Mun Dam and its Fish Ladder’ (2001 Study )

Pak Mun Dam

From ON THE RIVER OF NO RETURNS: THAILAND’S PAK MUN DAM AND ITS FISH LADDER, Tyson R. Roberts, ThaiScience 2001 (pdf)

Most fish species living in the Mun River are unable to climb or are for other reasons not using the ladder installed on Pak Mun Dam. This is especially true for large species most important in wild-capture fisheries. The ladder is unsuccessful in maintaining fish spawning migrations because few or no gravid females of any species climb it. Various proponents of Pak Mun Dam claim that its main impact on fish is that they cannot swim upstream and downstream past the dam. This is far from the only impact. The real problem is not with the ladder. Rather Pak Mun Dam itself is ecologically unfriendly to fishes.

A reservoir outflow is not a normal river. The abnormal flow regime and other artificial features in the outflow of Pak Mun Dam have severe impacts on fishes for 4.5 km until it joins the Mekong mainstream which dissipates (but is also effected by) its negative impacts. Pak Mun Reservoir is also very unfriendly to fish. This apparently is due mainly to having its bottom smothered by silt and its open water with an exceptionally heavy silt load at all times because of the highly abnormal “run of the river” flow conditions.

When the water level in Pak Moo Reservoir is at 108 m. “peak electricity generation” causes daily fluctuations in water flow downstream from Pak Mun Dam and daily draw-downs in the reservoir that disturb fish habitats and disrupt fish migration. If reservoir water levels are too low, the amount of water released from the sluice gates may be less than the lowest flow that normally occurs for only a few days or weeks of particularly dry years (if the reservoir level falls below 94 m the outflow will stop altogether). During minimum outflow the water quality also can be much poorer than that of normal dry-season low water without the dam. The other extreme occurs when water has to be released to prevent the reservoir itself from over-flowing. Opening the sluice gates on the spillways when the reservoir level is high can create a destructive torrent far stronger than any that occurred during the worst floods in the Moo River before Pak Moo Dam. Maximum as well as minimum outflows from Pak Moo Reservoir are lethal to fish.

The problem of Pak Mun Dam and fisheries may be summarized as follows: an artificial and hostile downstream environment (reservoir outflow) and an artificial and hostile upstream environment (reservoir) are connected by artificial and hostile corridors (fish ladder and dam spill-ways). The resulting impact accumulation has devastating over-all effects on fish habitats and fish species. Pak Mun Dam together with its 35-km long reservoir and 4.5 km reservoir outflow is a major geographic barrier to all kinds of fish movements between the Mekong and the Mun.

Biomass supply chains developed by VTT speed up use of bioenergy in Vietnam

VTT Technical Research Centre of Finland has developed efficiency in the biomass supply and use for energy in Vietnam\’s Mekong Delta as part of the Energy and Environment Partnership Programme of the Ministry for Foreign Affairs. Mechanisation of loading and unloading of biomass working phases reduce transport costs by 15%. The production and use of biomass pellets in industrial boilers was demonstrated to be financially and technologically sound.

Vietnam possesses considerable biomass reserves. Development of the current biomass supply chains and power plant operations will increase the use of biomass fuels for energy.

VTT\’s task in Vietnam was to develop efficient and reliable biomass supply chains for multi-fuel CHP power plants and industrial boilers. At the beginning of the project, VTT developed five new biomass supply technologies, three of which were selected for practical demonstration in the Mekong Delta.

via Biomass supply chains developed by VTT speed up use of bioenergy in Vietnam.

Scientist Disputes Laos’ Claim About Dam | The Cambodia Daily

Scientist Disputes Laos’ Claim About Dam | The Cambodia Daily

The Lao government believes that the Don Sahong dam, which is to be built on a stretch of the Mekong River just 1 km from the Cam­bodian border, will have no significant consequences for fisheries in downriver countries, according to documents released Wednesday by the Mekong River Commission.

According to a cumulative im­pact assessment—which was carried out by Laos and at­tempts to measure the dam’s im­pact in the region—the impact of the dam will be “insignificant.”

“[The dam] will not have significant cumulative impacts on the Mekong River flows, sediment transport, fish migration, or fisheries,” according to the report, dated January 2013.

The report notes that Mekong fisheries could be affected but only if the project is poorly managed.

“If poorly managed, this project would exacerbate the existing natural ‘choke’ on fish migration at this location in the system,” the report says.

However, the dam’s placement in only one of 17 channels, which allows fish to access other migration routes on the Mekong, the re­port continues.

The dam’s environmental im­pact assessment (EIA) report also says the project does not have measures in place to mitigate the alteration of river flow and sediments, as they will not be affected by the dam.

“As the [Don Sahong dam] will not significantly increase any of these threats, no mitigation or management actions have been proposed for them by this project,” the EIA report states, adding that the region’s fisheries face more of a threat from over-fishing than migration routes blocked by the dam.

Ian Baird, assistant professor of geography at the University of Wis­consin-Madison—and one of the foremost scientists of Laos’ Khone Falls fisheries who has produced numerous scientific articles on that area’s fish migration and biodiversity—said in an email that it was false for the report to infer that the dam would not impact downstream countries.

“[I]t is completely inaccurate to claim that the dam would not have any impact on Cambodia, Vietnam or Thailand. It will—the only question is how much,” he said. “The stakes are simply too high to test out these unproven measures on such an important resource for the whole region.”

“Everything is so far unproven, and there is no guarantee that any of the parts of the mitigation plan will be successful,” Mr. Baird said. “The authors of the studies admit as much, but they do not offer to be responsible for miscalculations.”

via Scientist Disputes Laos’ Claim About Dam | The Cambodia Daily.