Dynamics of bacterial community in Tonle Sap Lake, a large tropical flood-pulse system in Southeast Asia

2019 ◽  
Vol 664 ◽  
pp. 414-423 ◽  
Author(s):  
Porsry Ung ◽  
Chanthol Peng ◽  
Sokunsreiroat Yuk ◽  
Reasmey Tan ◽  
Vannak Ann ◽  
...  
2017 ◽  
Vol 549 ◽  
pp. 79-91 ◽  
Author(s):  
William C. Burnett ◽  
Gullaya Wattayakorn ◽  
Ratsirin Supcharoen ◽  
Khamfeuane Sioudom ◽  
Veasna Kum ◽  
...  

2021 ◽  
Author(s):  
Aifang Chen ◽  
Junguo Liu ◽  
Matti Kummu ◽  
Olli Varis ◽  
Qiuhong Tang ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1904
Author(s):  
Suzanne J. Kelson ◽  
Zeb Hogan ◽  
Christopher L. Jerde ◽  
Sudeep Chandra ◽  
Peng Bun Ngor ◽  
...  

The Tonle Sap Lake and River ecosystem in the Lower Mekong Basin of Southeast Asia is one of the most productive inland fisheries globally but is currently threatened by overfishing, dam construction, and climate change. We compare the catch composition and amount from 2007–2013 of two fishery gear types, the bagnets of the largest commercial fishery, the Dai fishery, and gillnets, which are deployed ubiquitously by independent fishers. We found that the two methods captured a similar number of genera (81 and 88 in the Dai and gillnet). Catches of both fisheries were dominated (>75%) by three genera that migrate longitudinally, Henicorhynchus, Labiobarbus, and Paralaubuca. The catch of the Dai fishery followed annual variation in the flood pulse extent, but the gillnet catch did not. We used resource selection ratios to quantify selection pressure by the gillnet fishery, relative to the Dai fishery, on fish from different genera and trait groups. The gillnet selected for fish that migrate laterally from the floodplain to the main river and for higher trophic level fish. Gillnets may target groups of fish that are less impacted by the long-standing Dai fishery. For both fisheries, we note a need for monitoring fish lengths in order to understand the effects of selection on population dynamics and species-specific trait changes.


Author(s):  
W. Qu ◽  
N. Hu ◽  
J. Fu ◽  
J. Lu ◽  
H. Lu ◽  
...  

The economic value of the Tonle Sap Lake Floodplain to Cambodia is among the highest provided to a nation by a single ecosystem around the world. The flow of Mekong River is the primary factor affecting the Tonle Sap Lake Floodplain. The Tonle Sap Lake also plays a very important role in regulating the downstream flood of Mekong River. Hence, it is necessary to understand its temporal changes of lake surface and water storage and to analyse its relation with the flood processes of Mekong River. Monthly lake surface and water storage from July 2013 to May 2014 were first monitored based on remote sensing data. The relationship between water surface and accumulative water storage change was then established. In combination with hydrological modelling results of Mekong River Basin, the relation between the lake’s water storage and the runoff of Mekong River was analysed. It is found that the water storage has a sharp increase from September to December and, after reaching its maximum in December, water storage quickly decreases with a 38.8&amp;thinsp;billion&amp;thinsp;m<sup>3</sup> of drop in only half month time from December to January, while it keeps rather stable at a lower level in other months. There is a two months’ time lag between the maximum lake water storage and the Mekong River peak flood, which shows the lake’s huge flood regulation role to downstream Mekong River. It shows that this remote sensing approach is feasible and reliable in quantitative monitoring of data scarce lakes.


2020 ◽  
Author(s):  
Amy Fallon ◽  
Marko Keskinen

&lt;p&gt;Growing water scarcity around the world is a crucial issue driven by global environmental change, as well as increasing competition for water resources for different economic and social pursuits. Climate change will have far-reaching consequences for water resources, particularly through increasing frequency and intensity of extreme weather events, such as droughts and floods. Such changes will acutely impact water and food security in developing countries, where large proportions of society depend on natural resources for their livelihoods. This can significantly undermine the resilience of such complex social-ecological systems, and the fulfilment of SDGs, including water-related SDG 6.&lt;/p&gt;&lt;p&gt;The capacity of freshwater systems to cope with stresses and shocks can be weakened when irreversible changes occur and thresholds are exceeded. It is therefore important for water governance arrangements to incorporate characteristics such as non-linear dynamics and unpredictability. Resilience is also gaining traction as a holistic framework to examine social-ecological system components, processes and feedback loops under change across scales. However, resilience has been critiqued for its inability to appropriately reflect socio-political dynamics, including power asymmetries, cultural values, and human well-being.&lt;/p&gt;&lt;p&gt;In this presentation, a novel theoretical framework for studying and describing resilience is presented for the analysis of freshwater system governance, using three dimensions of resilience across multiple scales of society: absorptive, adaptive, and transformative capacity. The audience is encouraged to engage critically with the concept, asking the question &amp;#8220;resilience of what, to what, and for whom?&amp;#8221;. In doing so, we will also address the typically narrow technical focus on resilience, and its potential challenges in achieving societal resilience to climate extremes.&lt;/p&gt;&lt;p&gt;The framework is applied to Cambodia&amp;#8217;s Tonle Sap and its hydrologically and culturally unique flood pulse system. The lake provides food security for millions, yet is undergoing negative ecological and social transformation due to pressures along the Mekong River including climate change, hydropower development, and weak governance. The changing dynamics in its flood pulse system and an increasingly complex socio-political landscape are presented through the framework, addressing both positive and negative components of resilience. In this way, the framework helps to put the current research and actions on the lake&amp;#8217;s management into the broader context of resilience and change.&lt;/p&gt;&lt;p&gt;We will demonstrate absorptive and adaptive responses of people living on and around the lake, including urban migration and illegal fishing practices. The risk of so-called rigidity traps (inflexible system components) is also explored, including an increasingly resilient autocratic government regime &amp;#8211; and the potential of such rigidity traps to undermine the resilience of the overall system. An enduring status quo of narratives around agriculture and hydropower development is shown as a key aspect of resilience of the Tonle Sap. Finally, we will present the key windows of opportunity for transformation, focusing on the role of local, largely informal institutions in facilitating sustainable and equitable governance outcomes.&lt;/p&gt;&lt;p&gt;The key aims of this presentation are to present a novel framing of resilience that incorporates societal dimensions more fully, and to identify pathways for transformative change that benefit all relevant groups of society.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;


2021 ◽  
Vol 13 (19) ◽  
pp. 3972
Author(s):  
Yoichi Fujihara ◽  
Koki Okuyama ◽  
Keisuke Hoshikawa ◽  
Hideto Fujii ◽  
Takashi Nakamura ◽  
...  

The Tonle Sap Lake contains unique hydrological environments and ecosystems. Although water temperature is an important consideration in lake management, information on the water temperature of the lake is limited. Thus, we investigated the characteristics of the daytime water temperatures of the Tonle Sap Lake from 2000 to 2019 using MOD11A1, a Moderate Resolution Imaging Spectroradiometers (MODIS) product. Moreover, the relationship between water temperature fluctuations and hydrological–meteorological conditions was analyzed. The maximum and minimum daytime water temperatures were recorded in May (30.7 °C) and January (24.6 °C), respectively, each a month after the maximum and minimum air temperatures were recorded. The annual maximum, average, and minimum water levels showed a downward trend (−0.14, −0.08, and −0.01 m/y, respectively). The annual maximum water temperature increased at a rate of 0.17 °C/decade, whereas the annual minimum water temperature decreased at a rate of 0.91 °C/decade. The annual maximum daytime water temperature had a strong negative correlation with water level change (flood pulse) and a weaker correlation with air temperature. The annual minimum daytime water temperature presented the strongest positive correlation with water level change (flood pulse) in the previous year. However, there was no correlation between the annual minimum daytime water temperature and air temperature. These results indicate that water temperature in the Tonle Sap Lake is mainly affected by water level fluctuations, which are mainly driven by flood pulses.


2010 ◽  
Vol 1 (1) ◽  
pp. 87-101 ◽  
Author(s):  
Paula Nuorteva ◽  
Marko Keskinen ◽  
Olli Varis

The changing environment is expected to intensify the challenges that people in developing countries are facing, particularly among the groups whose livelihoods depend on natural resources. The adaptive capacity of livelihoods largely defines the extent to which people can cope with future environmental changes, whether caused by climate change or other factors such as land use changes and water resources development. This article analyses the resilience and adaptive capacity of rural livelihoods around Cambodia's Tonle Sap Lake, an exceptional lake-floodplain system dominated by flood pulse. The research findings demonstrate that despite the people's tradition of adapting to the remarkable seasonal variation of water and related resources, their capacity to adapt to unusual environmental changes is weak, with the poorest being clearly the most vulnerable group. Reasons for the weak resilience include villages' relatively homogenous livelihood structures, unjust governance practices, increasing inequality and the lack of opportunities for livelihood diversification. It is concluded that while climate change is likely to pose a remarkable challenge to people's livelihoods in the longer term, climate change adaptation activities should also take into account other environmental changes. Equally critical is the understanding of the broader socio-political context and its dynamics in increasing—and decreasing—livelihood resilience.


Ecosphere ◽  
2017 ◽  
Vol 8 (7) ◽  
pp. e01881 ◽  
Author(s):  
Thomas Pool ◽  
Gordon Holtgrieve ◽  
Vittoria Elliott ◽  
Kevin McCann ◽  
Bailey McMeans ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document