VIETNAM NATIONAL UNIVERSITY, HANOI VNU UNIVERSITY OF SCIENCE FACULTY OF ENVIRONMENT. Chu Thanh Thao

Transcription

1 VIETNAM NATIONAL UNIVERSITY, HANOI VNU UNIVERSITY OF SCIENCE FACULTY OF ENVIRONMENT Chu Thanh Thao THREAT ASSESSMENT TO THE CRITICALLY ENDANGERED SWINHOE S SOFTSHELL TURTLE (RAFETUS SWINHOEI) IN DONG MO LAKE Submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Environmental Science (Advanced Program) Hanoi

2 VIETNAM NATIONAL UNIVERSITY, HANOI VNU UNIVERSITY OF SCIENCE FACULTY OF ENVIRONMENT Chu Thanh Thao THREAT ASSESSMENT TO THE CRITICALLY ENDANGERED SWINHOE S SOFTSHELL TURTLE (RAFETUS SWINHOEI) IN DONG MO LAKE Submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Environmental Science (Advanced Program) Supervisor(s): Dr. Minh Le Hanoi

3 Acknowledgement First of all, I have to thank my supervisor, Dr. Le Duc Minh, who continuously supporting and advising me from the beginning. Without his dedicated involvement in every step throughout the process and suggestions, this paper would have never been accomplished. I would like to thank you very much for your patience, motivation and immense knowledge that you propagate for me. Besides my advisor, I would also like to show gratitude to Mr. Timothy McCormack for providing the valuable data and information for my thesis. My sincere thank also goes to Mr. Pham Van Thong and Mr. Nguyen Tai Thang ATP field officers, who had instructed and supported me during implementing this research. I especially thank them for many constructive ideas which are the essential inputs and encouragement for me. I thank Mr. Hoang Van Ha and Ms. Nguyen Thu Thuy for enlightening me during the first glance of research, and giving accurate comments during progress of writing thesis. I would also like to extend special thanks to the rest of the Asian Turtle Program (ATP) staffs who was always willing to help and encouraged me a great deal. Also I thank all teachers in the Faculty of Environmental Science, Hanoi University of Science Viet Nam National University who enthusiastically imparted useful knowledge in the past four and a half years.

4 Abbreviation ATP ENV FPD GIS IAS IUCN TCC TSA Asian Turtle Program Education for Nature Forest Protection Department Geographic Information System Invasive Alien Species International Union for Conservation of Nature Turtle Conservation Centre Turtle Survival Alliance

5 Table of Contents I. Introduction... 1 II. Overview Global threat assessment Introduction of Rafetus swinhoei Introduction Conservation status... 9 III. Naturally environmental and socioeconomic conditions Natural environment Geographic location Topography Geology and soils Climate and hydrology Socioeconomic conditions Population and labor force Economy IV. Research objectives and methodology Objectives Threats and scope Threats Scope Methodology Literature review Structured interview Mapping interview locations V. Results and Discussion Dong Mo Dam Tourism developments Fishing and hunting Invasive alien species... 33

6 5.1. Introduction of invasive alien species Mimosa pigra Trachemys scripta elegans Rank of threats Conservation value of Dong Mo Lake Discussion VI. Conclusion VII. Recommendations... 48

7 List of table Table 1.Score calculation and rank of threats from local people opinions Table 2.List of Mammals, Birds, Reptiles, Fishes and their conservation status in Dong Mo area. 43 List of figure Figure 1. The Rafetus swinhoei individual in Dong Mo Lake Figure 2.Map of Dong Mo Lake Figure 3.Interview map in Kim Son, Son Dong, Co Dong, Yen Bai Communes Figure 4.Lake water is going to flow over spillways Figure 5.The first time the bottom outlets had been opened Figure 6.Land reclamation of King s Island Golf Course Figure 7.Removal of fish hook lines floating on Dong Mo Lake Figure 8. Utilization of electrofishing Figure 9. The dense growth of Mimosa pigra along shoreline Figure 10.Trachemys scripta elegans in Dong Mo Lake Figure 11.Total scores of threats Figure 12.Map of Rafetus swinhoei observation location in Dong Mo Lake Figure 13.Maintenance activities of Golf Course... 46

8 I. Introduction Former Ha Tay Province is situated on the Red River Delta and was merged into Hanoi municipality in In terms of ecological zoning, it lies within the transition zone between the mountain forest ecosystem and the plain extending from the northwestern highland region to the southwestern lowland ecosystem. As a result, the topography of this region is diverse, ranging from natural to agricultural ecosystems including hills, mountains, lakes, and cultivation fields. There is also home to a high diversity of fauna and flora, typically in Ba Vi Mountain, which is one of the most important mountain ranges of Red River Delta [5]. Dong Mo Ngai Son Reservoir was formed when a dam was built between Dong Mo and Ngai Son Rivers. Its basin falls in the territory of Kim Son, Son Dong, Co Dong Communes, and part of Yen Bai Commune, Son Tay District, Hanoi City (former Ha Tay Province). Its perimeter is approximately 17 kilometers with an area of ca hectares when the water level is 21 meters and 21 islands and islets creating a spectacularly artificial scene. Several development projects have been undertaken to improve socioeconomic aspects of this region. An international standard King s Island Golf Course was built on 350 hectares of land in the center of the lake. It consists of two 18 hole golf courses Lakeside (1993) and Mountain View (2004) using artificial grass. It is considered as one of the most beautiful golf courses in the Southeast Asia, which attracts a large number of politicians, businessmen, tourists. It has also been selected to host national and international golf tournaments. In addition, the Culture Tourism Village of Vietnamese ethnic groups was established on a 1544 hectare area in the southern section of Dong Mo Ngai Son Reservoir. This site is a complex of traditional Vietnamese architectures, highlighting unique characteristics of ethnic minority cultures. With its construction starting in 2003, the Village that features values of the distinctive cultures of each of Vietnamese 54 ethnic groups, is an attractive destination for domestic and foreign tourists. However, Dong Mo Ngai Son Reservoir is not only exploited for tourism, but also serves as a water supply source for Thach That and Quoc Oai Districts along Tich River. Hence, irrigation infrastructures have been developed to utilize water resources of the lake, and provide sufficient resources for the Culture Tourism Village of Vietnamese ethnic groups [5, 6]. 1

9 Dong Mo Lake has recently received growing attention from both national and international conservation communities, because it is home to at least one individual of the Swinhoe s softshell turtle (Rafetus swinhoei), the rarest and largest freshwater turtle in the world with only three known remaining individuals after the death of the only male in Hoan Kiem Lake. In Vietnam, this species is called the legendary turtle since it has been long associated with the famous myth of Emperor Le Loi returning the magic sword to the Golden Turtle God in Hoan Kiem Lake after defeating Chinese invaders in the 15 th century [37]. Because of its critically endangered status, this species is protected under the Decree 160 issued by the government in Although this species is on the brink of extinction with only three living individuals, the hope for its survival is still remaining with the non stop efforts from scientists and conservationists using difference tools, e.g. artificial insemination for captive individuals in China and intensive surveys to locate additional individuals in the wild in both countries. Even though the development of tourism and infrastructures brought the undeniable benefits and a brand new face for the rural area surrounding Dong Mo Lake, the natural ecosystem has been seriously disturbed and damaged as the result. Nonetheless, the impacts have been largely neglected so far. In addition, the daily activities of local people directly affect the Rafetus swinhoei individual. Invasive species have been established quickly in Dong Mo Ngai Son area to an alarming level. Although Dong Mo Rafetus is a scared species and a spiritual turtle to Vietnamese people, there is no fully study carried out in this region to assess the anthropogenic impacts on this critically endangered turtle which possibly risk its existence. To fill this important gap, I decided to conduct the research project entitled Threat assessment to the critically endangered Swinhoe s Softshell Turtle (Rafetus swinhoei) in Dong Mo Lake. 2

10 II. Overview 1. Global threat assessment A threat is defined as any human activity or process that has caused, is causing, or may cause harm, death, or behavioral changes to a wildlife species at risk, or the destruction, degradation, and/or impairment of its habitat, to the extent that population level impacts occur. A human activity may exacerbate a natural process [28]. Threat assessment permits risks from multiple stressors to be evaluated and communicated in a logical, robust and transparent manner. The process therefore facilitates optimum decision making for the management of natural resources through complete use of available information on potential environmental stressors, and through participative consultation with all stakeholders. The aim of assessment process is to estimate the probability of adverse events from identified environmental stressors. Traditionally, it has been used to investigate the effects of the release of particular chemical pollutants (toxicants) into the receiving environment. However, it is now applied more broadly to assess the relative impact potential of multiple threats against measured and/or predicted impacts on environmental values (appropriate and measurable monitoring endpoints). Hence, threat assessment becomes a necessarily advantageous tool and has already been carried out in the variety of places and ecosystems globally. The basic process of threat assessment includes: (1) Identification of the Problem (Assessment of site specific information on stressors and environment, determine contaminant pathways if applicable, and determine the time frame that over which the problem operates); (2) Assess Extent (Field assessment: e.g. Bioassays, monitoring surveys etc.), Assess Effects (e.g. Chemical concentrations, spatial and temporal distribution); (3) Risk Characterization (Comparison of the Effect with the Extent, e.g. Using a GIS framework); (4) Risk Management and Reduction (Manage inputs and/or modify management practice); (5) Monitoring (Use early warning or rapid assessment indicators/ GIS based approach) [39]. Human activities now affect nearly every marine ecosystem. The number and variety of threats can be overwhelming to management and conservation efforts. Mapping where threats occur is important for management, but does not explicitly account for differences in the extent and nature of ecosystem responses to threats. For example, bottom trawl fisheries have significantly more severe and long 3

11 lasting impacts on epibenthic communities living on hard versus soft substrates and even greater impact with increasing water depth because individual growth rates decrease and recovery times increase. Understanding the differences in ecosystem response is also critical to knowing which threats have the biggest impact on different ecosystems and how to best address them at different scales. Quantifying these differences allows threats to be ranked based on the severity of their impact [23]. This ecosystem based survey identified increasing sea temperature, demersal destructive fishing, coastal development, point source and nonpoint source organic pollution, increasing sediment input, hypoxia, and direct human impact as the greatest threats, in decreasing order of importance although the previous species based approaches show that habitat degradation, pollution, invasive species, and overharvest (for marine species) are the greatest threats. The largest scale threats were climate change based threats, species invasion, and hypoxia. Experts considered ecosystems least resistant to and to have the longest recovery times from demersal destructive fishing, point source organic pollution, coastal development, and increasing sea surface temperature. Coastal development and recreational fishing were the highest threats within hard shelf ecosystems and ecotourism was ranked as a threat to hard and soft shelf ecosystems [23]. The results indicate that every marine ecosystem is affected by multiple threats and that many ecosystems are affected at some level by every identified threat. Only one of the greatest threats (highest impact scores) was ocean based (demersal destructive fishing); others (sea temperature rise, coastal development, point source organic pollution, increased sediment input, hypoxia, and direct human impact) are all driven by land based activities. Consequently, effective marine conservation and management will have to address terrestrial, freshwater, and marine based threats simultaneously. Ranking diverse threats and ecosystems in a comparable way can help organizations prioritize how to spend limited time and money. Regional organizations would be best served by adopting this method and redoing the ranking process for the region. The inclusion of scale as a vulnerability measure provides a method for assessing the necessary spatial scale at which management needs to act. It is encouraging that most threats act at fairly small spatial scales, although the sources of some of these localized threats can be 4

12 large (e.g., a large watershed that drains into a small estuary) and their overall spatial distribution may be extensive [23]. The Mediterranean Basin covers portions of three continents Africa, Asia, and Europe. Biodiversity in the hotspot has been impacted by humans for millennia, nonetheless, negative impacts increased substantially in the last century with the explosion in human population which has been accompanied by expansion of urban areas and creation of new ones, industrial and commercial developments, and associated infrastructure, particularly transportation systems, and with the booming and relatively recent Mediterranean tourism industry focused on the coastal areas. This has reflected itself with the widespread construction of hotels, marinas and associated developments, especially along coasts that caused the complete removal of natural vegetation, planting of ornamental trees, shrubs and grass for lawns and golf courses, filling in of small coastal wetlands and construction of new roads to give access to coastal areas. It also means that there are now few relatively undisturbed natural areas outside of protected areas and inaccessible mountain regions. 32% of freshwater fishes in the Mediterranean Basin are threatened by dam construction. A number of range restricted molluscs in North Africa are already feared to have gone extinct, as the rivers where they occurred are now completely dry for parts of the year (previously they flowed year round), due to a combination of climate change, increased water abstraction and construction of dams. Inappropriate water management in reservoirs and dams altered natural processes and animals behavior. Water intensive golf courses and lawns built as parts of tourism developments are the root cause of much erosion, pollution and sedimentation which threaten both the marine as well as terrestrial habitats [25]. Many species of animal are hunted for food or sport in the region, with hunting seasons and bag limits regulated under national or regional (for example, Europe) legislation, with penalties for violations. However, illegal hunting is widespread, even in some Europe countries notably in Malta. As human populations and levels of consumption increase, overfishing presents a growing threat to the region's fish diversity, with potentially significant indirect impacts on other species through, for example, depletion of food supply [25]. Invasive Alien Species (IAS) particularly threaten islands ecosystems, which are very rich in endemic species, often with small and isolated populations, because the island environments are often free of predators and competitors. Island species, 5

13 as a result, have lost defensive behaviors so this threat is probably the biggest on the Macaronesian sub region within the hotspot, and on some Mediterranean islands. The number of IAS introduced in the Mediterranean Basin has been growing. It is important to establish and/or participate in regional IAS networks, develop national and regional policies and strategies, promote training and capacity building within local management agencies, improve regulatory and legislative frameworks, and link local land managers and conservationists with the international community that has the expertise and resources to implement on the ground IAS eradications and/or control [25]. In United States, imperiled species have been threatened by five categories of threats: overexploitation, habitat destruction, pollution, the introduction of non native (alien) species, and the spread of diseases carried by alien species. As the human population of the United States continues to grow, one might predict an increase in the frequency of biodiversity threats associated with urbanization, such as infrastructure development, water development, and land conversion. Assessments of the threats to individual species are often based on the subjective opinions of knowledgeable individuals, rather than experimental evidence or quantitative data [27]. Habitat destruction and degradation emerged as the most pervasive threat to biodiversity, contributing to the endangered status of 85% of the 1880 imperiled species including 494 vertebrates, 331 invertebrates and 1055 plants. Habitat destruction includes agriculture (affecting 38% of endangered species), commercial development (35%), water development (30% when agricultural diversion is included; 17% for just dams, impoundments, and other barriers), and infrastructure development (17%). Outdoor recreation also harms a large number of endangered species (27%). Indeed, habitat loss is the top ranked threat (in terms of the number of species it affected) for all species groups. Competition with or predation by alien species is the second ranked threat in the overall analysis, affecting 49% of imperiled species. Alien species can be brought into the country and released intentionally, or their release can occur as an unintentional byproduct of cultivation, commerce, tourism, or travel. The three leading threats to aquatic species nationwide were agricultural nonpoint pollution (e.g., siltation and nutrient inputs), alien species, and altered hydrologic regimes due to dams and impoundments. Aquatic species in the eastern United States are experiencing particular threats from 6

14 agricultural nonpoint pollution; in the West, the dominant threat is alien species, followed by habitat degradation and altered hydrologic regimes [27]. In Daly Basin in the Northern Territory of Australia, water extraction is primarily undertaken for agricultural and domestic purposes. It is a major issue for the Daly basin given that agriculture, including pastoral activities, dryland cropping, irrigated cropping and horticulture, comprises the major land use. As the use of groundwater is being promoted by the Northern Territory Government, over extraction of groundwater can result in draw down of the groundwater aquifer and flow on effects to groundwater dependent ecosystems. Reduced base flows could result in a deterioration of water quality and associated impacts to aquatic life. Drying of wetlands that are normally moist during most or all of the dry season would have deleterious consequences to native fauna, including small mammals, and possibly reptiles and others fauna. Extraction of surface water will result in reduced downstream flow and discharge, while over extraction can cause flows to cease [29]. Dams can have major effects on rivers and associated wetland habitats, as they result in the purposeful change in the flow regime of the river by altering one or more of its flow parameters: volume, rate, timing, direction and quality. Reductions in downstream flow and discharge variability both directly and indirectly results in a loss of biological diversity, including floodplain fish, migrant birds and other organisms whose life history strategies are linked to rises in water level and inundation of the floodplains. Other impacts on wetlands arising from the damming of rivers include destruction of upstream wetlands due to inundation, and deterioration of water quality such as eutrophication and anoxia. The major threats to wetlands associated with tourism are those of overuse, inappropriate recreational activities and infrastructure development. Typically, urban development, in and around a town such as Katherine, includes a full range of commercial, recreational and residential development. Major potential impacts to wetlands include destruction through drainage and infilling, reclamation and/or landscaping to improve an urban environment, over extraction of surface and/or groundwater for domestic purposes, nutrient enrichment, chemical contamination from domestic and industrial effluents, solid wastes and chemical pest control, and the introduction of exotic and sometimes invasive species [29]. 7

15 The land within the Daly basin identified as having highly potential is quite limited, representing less than 10% of the total area. However, this area is concentrated in one region, comprising the majority of the Douglas River, Stray Creek and Fergusson River catchments. Even with approximately 50% of the Daly River base flow being allocated for irrigation, the total irrigable area represents less than 1% of the Daly basin. Currently, urban development is concentrated in the Katherine region, and only represents about 2% of the area of the Daly basin. However, with the Katherine River contributing approximately 40% of the total discharge of the Daly River, any development activity in the catchment has the potential to negatively impact on the water regime of the Daly basin. The successful conservation of wetlands in the Daly catchment will require the identification of priority areas where development and habitat transformation and fragmentation should be discouraged and conservation efforts, such as the establishment of conservancies and their subsequent management, should be promoted [29]. In summary, ecosystems around the world have been enduring multiple stressors from human developments; therefore, threat assessment investigating the combination of impacts on environment is now popular and vital to warn about existing threats, and create basis for improvement and mitigation strategies. Those previous studies provided the orientation for this research, and suggested many common threats to organisms and ecosystem. 2. Introduction of Rafetus swinhoei 2.1. Introduction Rafetus swinhoei, also known as Yangtze Softshell Turtle, Shanghai Softshell Turtle or Swinhoe s Softshell Turtle, was first described in It holds the title of being the largest freshwater turtle in the world. The Rafetus swinhoei in Vietnam is considered as the legendary turtle, and locally known as the Hoan Kiem turtle. According to the legend that dates back to the 15 th century, King Le Loi, the founder of the Le Dynasty, was out on the lake after his victory over the invading Chinese army when a giant turtle emerged and took back the magical sword that was given to him to use in the battle. Following this event, the name of the lake was changed from the Green Lake to Hoan Kiem Lake which translates as the Lake of Returned Sword [37]. 8

16 This species is a large softshell turtle of the family Trionychidae, which means it has a bony carapace plate surrounded by cartilage covered in skin with the size of over 50 centimeters. Their long head with the length of 20 centimeters and width of 10 centimeters features pig like snout. They can reach over 100 centimeters in length, 70 centimeters in width and weigh ca kilograms. The male is smaller than female one, but has bigger and longer tail. The species was historically distributed in rivers and associated wetlands in northern Vietnam and southern China as far north as the Yangtze River. During the 1970s to 1990s, the species suffered from a dramatic decline largely due to hunting, mostly for local consumption of food, and through habitat loss and alteration, with streams and wetlands dammed or converted to agriculture such as rice cultivation [37] Conservation status The Rafetus swinhoei was listed as Critically Endangered by the Red List of the International Union for the Conservation of Nature (IUCN) in 2016, and classified as one of the top 25 endangered turtles in the world by the Turtle Conservation Fund in In 2013, the Vietnam government issued the Decree 160/2013/ND-CP to provide criteria for identification and management of endangered and rare species under prioritized protection. Importantly for turtles, 10 species were listed as fully protected, seven of which were already protected under the existing wildlife protection law Decree 32/2006/ND-CP and marine protection law Decree 59/2005/ND-CP. The three significant additions are the critically endangered Indochinese Box Turtle (Cuora galbinifrons), Swinhoe s Softshell Turtle (Rafetus swinhoei), and the endangered Cantor's Softshell Turtle (Pelochelys cantorii) which are all given national protection for the first time. Moreover, Vietnam has been enthusiastically participating in international conventions and memorandum of understanding of turtle conservation and management. In recent years, Vietnam developed the Turtle Conservation Action Plan, particularly on freshwater turtle to protect, conserve and manage turtle species and their habitats [37]. After the death of the old male individual in Hoan Kiem Lake measuring approximately 130 centimeters in length and 170 kilograms on 19 th January, 2016, there are only three individuals left including an aged female and her apparently impotent male companion in China's Suzhou Zoo and one with unidentified sex in Dong Mo Lake, Hanoi City, Vietnam [37]. For the couple in China, previous 9

17 attempts at natural mating and traditional cloacal artificial insemination in 2008, 2009 and 2011 had failed, prompting Turtle Survival Alliance (TSA) and Chinese zoologists to attempt a bold procedure in April 2016, in which Dr. Gerald Kutchling lead a surgical team in an artificial insemination procedure that bypassed the complex cloaca and injected semen directly into the anesthetized female s oviducts. Hopes were high that at long last, fertile eggs would be produced. The female subsequently laid 65 eggs at the Suzhou Zoo, and in late June of 2016, Dr. Kutchling traveled to China to check for fertility. Unfortunately, candling the eggs revealed that all 65 were infertile. Although the effort of breeding the last Rafetus swinhoei has not succeeded yet, the associated scientists have no intention of giving up and will continuously try to save this species based on a great deal of the information gained from the experience [30]. The Dong Mo Rafetus, while special in its status as the only surviving individual of its species in the wild, is likely alone in the lake. Beginning in 2003, the Asian Turtle Program (ATP) of Indo Myanmar Conservation conducted many surveys and interviews in eight northern provinces of Vietnam. During those fieldtrips, researchers found carapaces and skulls of six Rafetus swinhoei individuals, and habitats of wild populations possibly still remain. The first three regions chosen for six month survey were Thanh Hoa, old Ha Tay and Yen Bai Provinces [1]. The Rafetus Team Vietnam was established in September of 2007 when local reports suggested the presence of a large softshell turtle in Dong Mo Lake, west of Hanoi (old Ha Tay Province). Following a series of interviews with local fishermen confirming the presence of a large turtle, a full time team was put on the ground, conducting patrols, establishing observation posts, and monitoring fishing and other activities in the lake until the turtle was spotted and photographed in November 2007, finally confirming the presence of Rafetus swinhoei in the lake. The Rafetus swinhoei Conservation Project is administered by ATP and Education for Nature Vietnam (ENV). At this time, the ATP has undertaken a full time effort to ensure that the Dong Mo Rafetus is protected in its native habitat. The Rafetus Conservation Project has received support from the Turtle Survival Alliance, Turtle Conservation Fund, The Wade Foundation, and the Melbourne Zoo [26]. One of project staff is an indigenous person as well as an ex fisherman who has a broad understanding of his residence. Thanks to his attendant, this project has been receiving support from local people. Since the turtle was discovered, ATP staff has been frequently patrolling and monitoring Dong Mo Lake. The long term 10

18 observation program from January 2007 till now allows ATP to record the additive behaviors of this species [1]. Figure 1. The Rafetus swinhoei individual in Dong Mo Lake (Photo by: Timothy McCormack ATP) Awareness improvement programs for local communities have been implemented, focusing on lessons for students and communication meetings for fishermen [1]. Between the 7 th to 9 th October, 2013, ATP conducted school programs on Swinhoe s softshell turtle and other Vietnam turtles in two schools around Dong Mo Lake for 313 students from 9 th grades. Since 2009, over 2460 students have participated in awareness activities for Rafetus swinhoei in Vietnam. Thousands more people have been involved in activities supported by the ATP including sporting events, mid autumn festival and an art competition linked to conservation of the Swinhoe s softshell turtle. Fishermen of Dong Mo Lake have signed agreements which regulate harmful fishing methods, and guarantee no poaching of the giant turtles [15]. From 12 th to 17 th January, 2015, ATP staffs and fisherman team worked to create an artificial nesting beach for Swinhoe s softshell turtle in Dong Mo Lake. The sand bank was built on a small artificial island in the lake that is secure, only accessible by boat. Measuring 10 x 5 meters with a sand ramp extending down to the water, at the end of summer 2015 with low water in the lake the sand ramp would be extended to provide year round access to the turtles 11

19 [11]. From 3 rd to 9 th February, 2015, two no fishing zones were created in Dong Mo Lake. The zones which have been constructed by ATP help protect important areas, the largest is 17 ha in the deepest section of the lake where the turtle is most often seen surfacing and active. The smaller 1.4 ha is located in front of a constructed sand bank [16]. Additional conservation efforts in Vietnam aim at finding other living Rafetus in the wild. On 10 th May, 2015, the Forest Protection Department (FPD) of a northern province in Vietnam contacted ATP in Hanoi to report the discovery of a giant softshell turtle in a large lake. A rapid survey undertaken between 19 th and 22 nd May, 2015 by ATP corroborated this information. During 20 interviews with locals, 11 people reported having seen a huge softshell turtle in the past, most sightings being around a decade ago. But two interviewees, a boat captain and a member of FPD, claimed to have seen a large animal over 100 kilograms in size since A local counterpart has been hired at the site to gather additional information, monitor the site, and ATP planned to undertake full time monitoring at the site during the summer. ATP has local counterparts now at six sites for which interviews have reported large softshell turtles believed to be Rafetus swinhoei, two of these sites were identified in 2015 [12]. Another option for breeding the species is to capture and transport the Dong Mo turtle to China to rebuild the population, but the politics is complicated. Vietnamese conservationists express doubts that authorities would be willing to send Vietnam's only known Rafetus to China. A better possibility would be to collect and deliver his sperm, if it is a male, to the Chinese zoo [35]. III. Naturally environmental and socioeconomic conditions 1. Natural environment 1.1. Geographic location Dong Mo Ngai Son Reservoir was formed in The North is Kim Son Commune, Son Tay District. The East is Son Dong and Co Dong Commune, Son Tay District. The South is Co Dong Commune, Son Tay District. The West is a part of Co Dong Commune, Son Tay District, but the majority is in Yen Bai and Van Hoa Commune, Ba Vi District [5]. 12

20 Figure 2.Map of Dong Mo Lake 1.2. Topography Dong Mo Ngai Son area is located near a mountainous terrain of Ba Vi mountain range, and its elevation is ca. 100 meters above sea level. The main type of topography is bowl shaped hills in the eastern side of Ba Vi foothill. Vai Hill in Kim Son Commune is the highest hill with the height of 113 meters. Because of the intense flows running from Tan Vien Mountain (Ba Vi mountain range) in rainy season, this hilly region was abraded to form streams of different size, some of which flow into Dong Mo Ngai Son Lake, such as Muoi River and Co River. The eastern and southeastern sides of Tan Vien Mountain form the headwater of the hydrological system of Dong Mo Ngai Son Lake [5] Geology and soils The geology of Dong Mo Ngai Son area along with Ba Vi Mountain s geology was formed during the Hercynian orogeny ca. 200 million years ago, in the last period of Paleozoic Era The Permian (P2). The typical rock and soil types are lime schist and silica schist. Bauxite and coal covered by basic magma occur in 13

21 many places, most of which are green porphyrit deposited from volcanic activities at the boundary between Hoa Binh and old Ha Tay Province [5] Climate and hydrology The climate of Dong Mo Ngai Son area is characterized by the long period of hot weather and the large amount of precipitation of northern Delta. The average annual temperature is 24 o C, and the average winter temperature falls to below 18 o C. Nevertheless, with the complex features of hilly region and laterite gravel at the surface of old alluvium, this region has its own microclimate. The highest summer temperature here is approximately o C higher than in the plain. The absolute maximum temperature is 39 o C, and minimum is 5 o C. Day night temperature difference in this area is greater compared to the eastern Delta. Because of the erratic fluctuations of climate, there were occasionally hot days up to o C or heavy rainfall and thunderstorm with the precipitation rate of millimeters per day occurring in coldest months of winter. Located on the windy eastern mountainside of Ba Vi mountain range, the amount of precipitation in Dong Mo Ngai Son area is considerably high with around 2000 millimeters per year, and the number of rainy days in a year is Northeast and southeast winds are two prevailing winds in winter. However, the Southeast wind is more dominant occupying 52.5% and prevailing in almost every month of the year while the Northeast wind only accounts for 35.8%. The relative humidity is regularly high (above 80%) even though it changes seasonally, and is different between the most humid month March (89%) and the driest month January (82%) [5]. 2. Socioeconomic conditions 2.1. Population and labor force According to the local data recorded until December 2002, the total population of three communes Kim Son, Co Dong, Son Dong in Dong Mo Ngai Son area was people with 6219 households in 39 villages. The average population density was 436 people per square kilometers. Among three communes, the highest population density is 542 people per square kilometers in Son Dong Commune, and the lowest is 370 people per square kilometers in Kim Son Commune. Agriculture is the main economic occupation of three communes. According to the statistics of 2002, there were 3899 farmers occupying 71.9% of total 14

22 commune population with 817 agricultural households accounting for 65.26% of total commune households in Kim Son Commune while Son Dong Commune had 3388 farmers making up 73.6% of total commune population with 1217 agricultural households occupying 61.65% of total commune households. In Co Dong Commune, 6432 residents were working as farmer accounting for 68.14% of total commune population with 918 agricultural households making up 38.86% of total commune households [5] Economy Cultivation - Kim Son Commune: In 2002, the total area of agricultural land was hectares accounting for 29.56% of total area of natural land, among which 182 hectares was paddy fields producing 965 tons of rice. Maize farming was maintained with average productivity of 3000 kilograms per hectare. The development of peanut and soybean was shifted to commodity production with the area of 50 hectares yielding kilograms per hectare. Potatoes were planting on 25 hectares of land. The total rice quantity harvested in 2002 was 1080 tons, and per capita food supply was 200 kilograms per person per year. - Son Dong Commune: Food cultivation was oriented to intensive farming, and took a leading position in the agricultural industry. New high yielding varieties of crops, for example China hybrid rice and corn 888, Bioseed, contributed to the productivity improvement. In 2002, with hectares of cultivation, the achieved quantity was tons. Besides, the short term industrial crops were also an important factor to increase the value of total agricultural product. The area of industrial crops in 2002 was hectares with the total yield of tons. - Co Dong Commune: Economy, especially agricultural production and production services activities, significantly grew due to agricultural encouragement and restructuring the economy towards commodity production. Advances in science and technology, particularly in crop breeding, were widely applied boosting the efficiency of production, soil utilization, and crop productivity. The crop yield was 3078 tons in Yen Bai Commune: Campaigns Restructuring cultivation and livestock to raise agricultural value, high tech intensive farming, developing large 15

23 scale farming models, new rural development and land regrouping advanced the growth of agricultural production to average level, contributed to the positive change of rural area, and improved inhabitants living standard. In 2015, the rice yield was tons. The area of tea tree was 415 hectares with the tea bud productivity of 17 tons per year Livestock farming - Kim Son Commune: The total number of cattle in 2002 was 908, among which dairy cow was increased to 179 while there were 1931 pigs. The total number of poultry was up to The development of livestock farming was based on the orientation of commodity production and the application of science and technology advances. - Son Dong Commune: Science, technology advances and economic farming models were applied to growing livestock. There were 1502 cattle, and the number of pigs was The effort in vaccination against diseases was efficient when almost no cattle and poultry epidemic occurred over the last few years. - Co Dong Commune: The trend in livestock farming was concentration and work assignment for each household to have specialized farmers in short term production cycle, and rapid capital turnover. In 2002, the total number of cattle was 1387, and there were 4750 pigs. The total number of poultry was ca with 11 industrial chicken farms. - Yen Bai Commune: The development of livestock was sustainable with a focus on the profitable dairy cows with the number of Handicraft, trade and service - Kim Son Commune: The product value of this economic sector brought the commune a high income occupying 33% of gross annual product of the commune. Nevertheless, the characteristics of production activities here were limited to household scale and spontaneous serving for the local needs. - Son Dong Commune: Households taking advantage of living near highway and provincial road opened service shop houses, including welding, tailoring, carpentry, masonry, and milling to serve the demand of local and adjacent areas. Although this business is small scale, and established by households and individuals, it is significantly developing and profitable. A large amount of local labor is employed by Dong Mo tourist resort located at Son Dong 16

24 Commune that largely resolve employment and income problems for local citizens. - Co Dong Commune: Leisure farmers in post harvest period produce brick and lime utilizing the available material source; however, the scale of production is limited to households and individuals. Since there are lots of agencies, military organizations stationed at this commune and Dong Mo tourist resort, it is the great opportunity to develop trade and service business, especially accommodation service and hotels [5]. IV. Research objectives and methodology 1. Objectives 1.1. General objective The purpose of this study is to assess factors considered as threats to the Swinhoe s softshell turtle (Rafetus swinhoei) individual in Dong Mo Lake from different dimensions, such as constructions, local people s activities and invasive species. Based on the information, conservation measures can be designed to better secure the only known wild individual of the rarest species in the world Specific objectives - Assess the risk and impacts of the dam, tourism developments, fishing and hunting of local people, and invasive species on the survival of the Rafetus swinhoei individual. - Rank those threats to determine the priority of concern. - Recommend potential solutions to mitigate adverse effects of those threats while not interfering the daily life of local people, local business, and the development of Dong Mo area. 2. Threats and scope 2.1. Threats - The dam built in Golf course and other developments within the area of Dong Mo Lake. - Communities of Kim Son, Son Dong, Co Dong, Yen Bai communes. - Invasive species in the area. 17

25 2.2. Scope To examine threats to the Swinhoe s softshell turtle, all elements exerting the influence on Dong Mo Lake and surrounding zones need to be assessed. For that reason, Kim Son, Son Dong, Co Dong and Yen Bai Communes are selected for thorough investigation since the location of the lake lies within the area of four communes. Although the amount of information provided by residents is variable between four communes as their uses of lake are different, understanding their views of the lake is important to ensure that the information collection is sufficient and factors are equally assessed. 3. Methodology 3.1. Literature review The study entitled Nghiên cứu, đánh giá hiện trạng và sử dụng bền vững đa dạng sinh học lưu vực hồ chứa Đồng Mô - Ngải Sơn phục vụ phát triển kinh tế - xã hội of Vietnam Academy of Science and Technology, the report of Yen Bai People s Committee and other works provided a good understanding of natural conditions, fauna composition of Dong Mo area and socioeconomic status of Kim Son, Son Dong, Co Dong, and Yen Bai Communes. Based on the available data in the studies, this research was able to move further in impact assessment of each factor. Additional data on threats to the ecosystem were collected from reliable scientific journals and publications. Furthermore, prior articles of Asian Turtle Program (ATP) published on the Rafetus swinhoei individual provided updated news and valuable detailed information about the current risks based on their long term monitoring program and working experience in protecting the species in the area. Moreover, workshop reports on this rare species suggested potential threats and some conservation measures Structured interview A structured interview was standardized in an order to ensure that the questions were answered within the same context and the variation in responses was limited. The usage of questionnaire was replicated with a fixed set of closed questions. Respondents was able to choose from a list of given alternatives to facilitate subsequent analyses. The alternatives, included open ended questions to obtain elaborate, thoughtful answers. 18

26 Thirty five people were interviewed to obtain their own opinions about how the development of constructions around the lake and invasive species threaten the Rafetus swinhoei turtle as well as indigenous knowledge about the side effects of fishing, hunting techniques and the protection issue. Random selection of interviewees was employed to make sure that the collected information was not biased to any specific groups such as fishermen or farmers. When undertaking interviews, the isolation methods was applied. Respondents were interviewed one by one, not in a group. In addition, people, who were drinking, were not selected for interview to avoid incorrect information. Each interview lasted from 10 to 25 minutes depending on the knowledge of respondents. All information provided by local people was recorded in prepared questionnaire form (see the Appendix). Questions used in interviews focused on fishing, hunting and invasive species based on indigenous knowledge. Some examples are listed below: - List all the non electric fishing methods? - Have you witnessed other locals using electrofishing method recently? - What other types of animal does indigenous people hunt excluding fish and shrimp? List all the methods. - Have you ever witnessed the Swinhoe s softshell turtle caught? - Do fishing techniques threaten the Dong Mo Rafetus and other turtle species (softshell turtle)? If yes, which techniques? How/Why? - When did Mimosa pigra first appear in Dong Mo area? Do you know their source of introduction? - When did Trachemys scripta elegans first appear in Dong Mo area? Do you know their source of introduction? 3.3. Mapping interview locations Interview locations consisting of latitude and longitude were recorded by smartphone, then were marked on map using ArcGIS 9.2. Location data was used in fieldtrips for quality control purposes, understanding the areas covered by interview surveys and identifying gaps in the study Identification of threats There are six threats to the Dong Mo Rafetus including Dong Mo Dam, tourism developments, fishing, hunting, Mimosa pigra, and Trachemys scripta 19

27 elegans. TRA (Threats Reduction Assessment) method was used to assess the severity level and impact extent of those threats. The interviewees in four communes were asked to score each factor on a scale of 1 to 6 with 6 for the highest threat, and 1 for the lowest. After collecting the results, the total score of each factor was calculated to rank six threats. The highest score indicated the most influential threat that risked the survival of the Swinhoe s softshell turtle in Dong Mo Lake [7,21]. V. Results and Discussion 1. Interview survey Thirty five interviews including ten in Kim Son Commune, ten in Son Dong Commune, five in Co Dong Commune, and ten in Yen Bai Commune were conducted from 12 th to 16 th September, Figure 3.Interview map in Kim Son, Son Dong, Co Dong, Yen Bai Communes 20

28 2. Dong Mo Dam After the collapse of the old dam in 2008, the new Dong Mo Dam was constructed on the base of the old dam. The new dam is bigger in size with four large floodgates, each one is 4 meters in width and 10 meters in height. It is also different from the old dam structured with spillways that water automatically flows over them when the water level equals to the crest elevation of the dam. The bottom outlets were added to support the operation of the dam in preventing the water from overtopping and damaging or even destroying the dam. From the results of interview surveys, 17.14% of locals supposed that the dam only affected the lake through decreasing the water level due to the lower setting maximum water elevation which prevents flooding, permits the farmers produce extra crop season, but narrows the lake surface area, and reduces the productivity of fish and shrimp in the lake. On the contrary, 31.43% of opinions suggested that the Dong Mo Rafetus is threatened by the dam since it can escape from the lake when the floodgates are opened, and the habitat is narrowed along with the smaller lake surface area. The remaining 51.43% thought that the dam causes no harm to the turtle. The local people showed low level of concern to the fate of aquatic animals in case of releasing water when their responses more focused on the slight influence of water level change on life of most of them due to the dam. Thus, although more than a half of the interviewees found no risk from the dam, it is still a potential threat to the turtle based on the experience of ATP and practical demonstrations. When the spillways release excess water to Tich Giang River to protect agricultural lands of indigenous people and tourism areas, and the Golf Course from inundation, the turtle can be excited by the torrent swimming toward the dam gates, then escape from the lake. It can also get severe external injuries or internal damages by falling from the spillways into water because of the height difference between upstream and downstream. The best example for this threat is the incident occuring in the 2008 historic flood in Hanoi City. When the old dam was broken due to the violent flood, the turtle escaped and was caught by a local fisherman in Coi Village, Trung Son Tram Commune, Son Tay District on 26 th November after getting entangled in nets local people installing to capture fishes coming out of the lake. At that time, the turtle weighed 69 kilograms, and its carapace was 90 centimeters in length and 70 centimeters in width [2]. After receiving the information of the turtle, the FPD, police, government officials, ATP, ENV and a team from the Turtle Conservation Centre (TCC) at Cuc Phuong National Park immediately arrived at the fisherman s 21

29 household and convinced him to hand over the turtle when he insisted on slaughtering for food or selling to China. The negotiation effort of local officers and staffs of conservation organizations in long hours was paid off when the fisherman accepted a compensation as a reward to release the turtle. The turtle was rescued successfully, then returned to the lake safely. To protect the turtle during the construction of the new dam, on July 2009, ATP set up a net of 55 meters in length and 7 meters in width across the lake. In the rainy season of 2011, a temporary net of 60 meters in length and 7 meters in width was placed behind the dam in the downstream river [19]. Nonetheless, the water level reached 20 meters, one more meter water above the current spillways. During that time, this net was submerged ca. 2 meters below water surface. To reduce the risk, an additional net on bamboo fence was installed in the lake, 50 meters in front of the dam although if the water level continued to increase, it would become useless since it emerged above the water surface only centimeters. The fence is moderately weak, and could be swept away by a strong water flow [4]. Figure 4.Lake water is going to flow over spillways (Photo by: Nguyen Van Trong ATP) The next problem is the bottom outlets. The hydrodynamic force of water flow can get the turtle stuck under the gates when the outlets are lifted to create small space for the water release. This may create a scenario in that its head can go 22

30 through but not the large body. Because of the intense flow to the downstream river, the turtle will be unable to escape to move back to the lake, and be drowned. Followed the warning of ATP about the threat of the bottom outlets to the turtle, the Lake Management Authority has restricted open times since the day the dam was completed. Nevertheless, in the case of emergency, they have no other choice except for opening the bottom outlets to avoid the dam collapse which will cause a disaster for downstream area. In September 2013, the volume of water exceeded the reservoir storage capacity. To cope with the situation, a plan to release water was informed that for first three days, four gates were lifted to 10 centimeters and 15 centimeters with two opened gates in the next nine days. Previously, the net system was set up beyond the floodgates by ATP and the lake owner to keep the turtle and fishes. One day before opening the outlets, the second net was added. However, based on their experience, ATP staff believed that the turtle was strong enough to break those nets. Those bottom outlets were opened at 9 am on October 7 th, 2013, and continued to discharge flood one week later. Fortunately, there was no regrettable accident [15]. On October 30 th, 2013, ATP installed two extra nets emerging from water surface with the ends of both reinforced concrete piles that supported the existing net system to distance the turtle from the floodgates in case they are occasionally opened to regulate lake water. Figure 5.The first time the bottom outlets had been opened (Photo by: Pham Van Thong ATP) 23

31 All the nets after long time usage have been worn out, and no longer serve their purpose of protecting the turtle. The latest net set in 2013 has sunk into the mud of the lake bed, and been harshly damaged by fishing activities. At the end of September 2016, ATP replaced it with a new 150 meter long and 20 meter high net to help handle the alarming water level rise after recent heavy precipitation [17]. This net is the one and only method to prevent the turtle from approaching the dam for the time being while the risk still exists during the flood season. If the Rafetus swinhoei individual escapes from the protected lake or is dead, it will be a huge loss to this species conservation and global biodiversity as well as a costly lesson for conservation community. 3. Tourism developments Following the requirements of the Golf Course, the spilling level was adjusted to the water level of 21.5 meters with the maximal surface area of Dong Mo Lake is 1200 hectares. The water level, which fluctuates seasonally, changes the lake surface area, varying from 900 hectares (level of 15 meters) to 1400 hectares (level of 23 meters). There are a lot of islands and peninsulas accounting for an area of 490 hectares on the lake. The total area of Dong Mo Ngai Son Reservoir is about 9700 hectares, and flood level is designed to reach maximum at meters corresponding to 1300 hectares of lake surface area [36]. The 36 hole King s Island Golf Course is situated on 350 hectares of land and 1500 hectares of waterfront. On the Lakeside course, the TifDwarf grass was chose to put fairly small greens. On the Mountainview, the greens were covered by Novotec grass which was imported from Australia. The Bermuda grass was planted on the fairways of both courses [41]. Apart from these two golf courses, other infrastructures were constructed including the Club house, 80 room hotel, 50 villas, a practice green, water sports, beach, and assisted facilities. The associated services of accommodation and food had been developed afterward consisting of Thien Ma Hotel and the system of other hotels, restaurants on islands of Dong Mo Lake. Notably, Thien Ma Hotel is located at the gateway of the international golf course near the lakeside. Likewise, there are 2 motorboats and 30 motor canoes serving the needs of tourists visiting islands on Dong Mo Lake [13]. The opening ceremony of Vietnam National Village for Ethnic Culture and Tourism was organized on September 19 th, 2010, officially operated part of the village to celebrate The Millennial Anniversary of Thang Long Hanoi. Vietnam 24

32 National Village for Ethnic Culture and Tourism is situated in the southern Dong Mo Lake. The North is Kim Son Commune, Son Tay District, the East is military barrack in Son Dong Commune, Son Tay District, the South is the extended Lang Hoa Lac Highway, Hoa Lac Airport in Yen Binh Commune, Thach That District, and the West is King Island s Golf Course in Yen Bai Commune, Ba Vi District. The total area of this village is 1544 hectares comprising 605 hectares of land and 939 hectares of lakefront that is divided into seven functional sections: - Vietnam ethnic villages: There are high hills, valley and waterfront on the area of hectares showing the distribution of ethnic villages throughout the country. - Culture and entertainment area: The center of cultural, sports and recreational activities has the size of hectares in the heart of the village. - The World s cultural heritage area: The complex of introducing various famous world s cultural heritage and reflecting the specialty of human culture is built on the area of 46.5 hectares. - Water surface park and marina area: The region of hectares is the combination of hectares of land and hectares of waterfront to organize tours, sports and services associated with Dong Mo water surface. - Vegetation and water surface area: The area of hectares is determined by water surface area with water level of 20 meters exploited for eco tourism activities with landscape, plants and lakefront. - General tourism services area: This hectare land is an integrated area of large scale tourism services and sports. - Administration office: Offices, public service house, accommodation for ethnic groups and reception house occupy the area of 78.5 hectares [9]. Several corporations have invested in tourism development in Son Tay District, one of which is Son Tay Travel, also is the most advantageous company in long term. It has the right to exploit for tourism on the area of hectares consisting of the 1.7 hectare Peninsula (Cam Hill), the 9.5 hectare Xiet Island, the 19 hectare Con Ma and Gieng Hills, the 12.2 hectare Chien Hao and Suoi Cau Islands, and the 60.8 hectare Pheo and Cao Hills in Kim Son Commune. 25

33 - The Peninsula (Cam Hill): The plantation office and lychee orchard on the land of 7000 square meters with water level of 17 meters in the lower area will be replaced by the complex of meeting rooms, office, gate and lane for boat docking, parking lot, 200 seat conference room, bar and kitchens for 250 people, 100 room hotel and a campus. A center of 10 small villas with port landing, waiting room, bars and security room will be built on the area of square meters with water level of 42 meters of mangium forest owned by the Dong Mo plantation. - Ke Xiet Island: When the water level is 24 meters, the island is separated into two small islands with the area of respectively 2.6 hectares and 4.5 hectares. Nonetheless, when it decreases to 20.5 meters, a land bridge appears connecting those small islands to form the land of 9.5 hectares. This flooded island is located in the northeast of the mainland, and at a distance of meters from it. There is a sloped hill with the height of meters and a large beach in the direction of the northwest of the Golf Course. The planned constructions are bar and receptionist, 50 seat dining room, 30 room hotel, 30 villas with garden, surface water recreation on beach, fishing spots. - Con Ma and Gieng Hills: There are two hill chains in the southwest along the lakeside covered by malaleuca and mangium with the total area of 130 hectares. Son Dong Commune s farmers have cultivated in the northeast region. The zone for small villages with orchards, 150 seat dining room with receptionist room, and a bar only occupies the land of 19 hectares. - Chien Hao and Suoi Cau Islands: When the water level is 24 meters, the area of Chien Hao Island is 9.6 hectares, then expands to 12.2 hectares when water recedes to 21.5 meters. The plan is to construct villas with orchard, beaches with surface water recreation and fishing spot, and walking lane. Suoi Cau Island has the size of 2.3 hectares when the water level is 24 meters, then expands to 5 hectares at 21.5 meters. The developments are an eco tourism resort, 5 villas with orchard, a small beach with surface water recreation and fishing spot, and walking lane. Pheo and Cao Hills: The total area of Pheo and Cao Hills is 45 hectares, Kim Son rehabilitation region is 6.6 hectares, and the University of Information is 8.2 hectares. The northeast side is adjacent to the lake, and the northwest side 26

34 borders the Kim Son Provincial Highway. The malaleuca forest and orchards of 327 projects by 46 newly households adopted the Garden Pond Cage Field model cover this region. The proposals include a beach with underwater recreation, 150 seat dining room with receptionist and bar, office and employees rooms, buildings of the University of Information, 50 villas with orchards, and an administration house with security [36]. From the results of interviews, 65.71% of locals suggested that the developments surround the lake pose a threat to the Swinhoe s softshell turtle as the extensive area of Golf Course encroaches the lake approximately meters equal to hundreds of hectares, and narrowing habitat of the turtle. In addition, all the constructions along lakeside narrows the basking sites of turtle, and is the source of noise. Construction works and activities of Golf Course throughout the day scare the turtle from coming near the shore. Pesticides and fertilizers used in the Golf Course and waste from tourism services and activities may pollute the water, or adversely affect the water quality as well as the aquatic species to some extent. On the contrary, another 34.29% insisted on no effect of the constructions on the turtle since the impact is minor compared to the spacious lake or that they have no direct threat on turtle. The outcome proves that the rapid development of constructions adversely affects the turtle in the lake, both directly and indirectly. The extension of Golf Course is in progress, and no accurate figures are available. Nevertheless, land reclamation creates unsustainable landuse, and encroach the lake surface area. The expansion may be negligible now, but in future, if other constructions also reclaim different parts of lake, the lake will be narrowed considerably that restricting habitat of the turtle. Although developments occupied scattered spots on lakeside, they accidentally narrow the basking sites and possibly nesting sites of the Rafetus swinhoei individual. Being a poikilotherm, sunbathing is essential for the turtle to warm up and maintain their body temperature. Basking raises the turtle s metabolism to facilitate digestion, bolster the immune system, and allows the skin to dry completely. Insufficient basking sites will lead to a whole host of potential health problems such as skin infections, shell rot, and ear abscesses [33]. Based on the records of ATP, the turtle regularly appears near the Golf Course, Xiet Island, Con Ma and Gieng Hills, Ngon Bong Sua area, Ngon Go Vuong area. However, some fishermen of Kim Son Commune shared that lately they only witness its head emerging from the water surface, but rarely crawling onto 27

35 the islands. There is the possibility that the choice of basking sites is diminished due to the loss of undisturbed natural areas. If this is the case, it has to stay underwater longer and is limited to sunbathing. Despite the fact that only one turtle was confirmed in the lake, fishermen insisted that they have observed two to three individuals with different sizes. If it is confirmed, there is a reason for hope that they will mate with each other, and reproduce in breeding season. Thus, the nesting sites are narrowed by infrastructures minimizing this fragile opportunity. Surface water recreation of Golf Course and Cultural Village take advantage of broad lake surface and several islands on lake. The activities of motorboats and canoes disturb the aquatic environment by noise, wave climate alteration and increase of water turbidity. The boat propeller will cause deep skin and carapace wounds for the turtle if it unintentionally swims nearby. Furthermore, to complete projects with numerous infrastructures, builders are required to work night shift under lighting that means the loud noise is emitted at all hours of the day and night. The Golf Course is also equipped the lighting system for night golf. Artificial light at night of construction sites and Golf Course can disrupt the turtle and other animals biological clock which maintains their circadian rhythm, and disorder the nesting mechanism at night or during the early morning hours of Rafetus, adding the noise from building activities, that terrify the turtle and prevent it from basking. In regards to fertilizer maintenance activities of Golf Course, there is no evidence of contamination to conclude the threat of those pesticides and fertilizers to the turtle before any water quality assessment is carried out. Figure 6.Land reclamation of King s Island Golf Course (Photo: Nguyen Van Trong ATP) 28

36 4. Fishing and hunting The common fishing methods of Dong Mo fishermen are fishnet, fishing rod, fish hook line, trawl, fishing hooves, shrimp trap, and electrofishing. From the results of interviews, 37.14% of locals indicated that fishing techniques including fish hook line, electrofishing, fishnet, fishing rod only affected small turtle Pelodiscus sinensis. On the contrary, 34.29% of opinions shared that using fish hook line, electrofishing, fishnet, fishing rod, and trawl can capture both the Swinhoe s softshell turtle and Chinese softshell turtle, or injure them. Among them, fish hook line and eletrofishing are mentioned the most. The remaining 28.57% believed that local fishing was not a threat to Rafetus swinhoei. The outcome demonstrates that softshell turtles are endangered by fishing practices. Fish hook line is extremely dangerous to the softshell turtles since ca hooks are tied to each line set floating on the lake. Those hooks are used in various sizes, the smallest one can cause the death of small softshell turtle such as Chinese softshell turtle (Pelodiscus sinensis), or injure and even threaten life of the larger relative Rafetus swinhoei. The main target of fish hook line is Chinese softshell turtle, but the Swinhoe s softshell turtle can be the unexpected catch. 40% of interviewees had observed the Rafetus being caught, most of which 25.71% are the cases in the period of 1980s to 1990s, and the remaining 14.29% are the 2008 incident when the dam collapsed and the 2015 failed capture. Lots of cases in that old time, when the turtle population in the lake was still high, were reported during the interviews. Two locals in Kim Son Commune caught some by themselves in 1990s with three individuals weighing 190 kilograms, 70 kilograms, 60 kilograms respectively using fish hook line, and one individual weighing 51 kilograms entangled in fishnet. The witness cases consist of 10 individuals (the biggest one weighed 120 kilograms), one individual weighing over 50 kilograms, one individual with the carapace of 80 to 100 centimeters all using fish hook line in Kim Son Commune, and three individuals (the biggest turtle weighed 200 kilograms and one weighed 131 kilograms) using fishnet and fishing rod, one individual weighing 70 kilograms using fish hook line in Son Dong Commune. Few inhabitants shared that this species were mainly captured by people from other provinces such as Thanh Hoa and Hai Phong Provinces, the locals only caught the small number of them. The purpose was locally consumption or sale to China and Hanoi City for VND to VND per kilogram. As shown in the record, the fish hook line utilized in the majority of cases shows that it is the danger to the Dong Mo Rafetus. 29

37 Moreover, since the R. swinhoei juvenile can be easily mistaken for Chinese softshell turtle, fishing of this unprotected species using fish hook line jeopardizes all stage of this species life. Although Mr. Pham Xuan Tu the lake owner has prohibited the long hook line since 2010 as part of the no hunting agreement to protect the Swinhoe s softshell turtle, they have been found within the habitat of turtle. In 2014, two cases of poachers using fish hook line were discovered and confiscated. However, in 2015, the cases of illegal fishing exceptionally escalated, and those lines were scattered over different zones of the lake that hindered ATP staffs with support of local fishermen from detection, then removal, and also increased the risk to the endangered turtle. From March 13 th to April 12 th, 2015, six long lines of hooks were found and removed by fishermen [20]. Figure 7.Removal of fish hook lines floating on Dong Mo Lake (Photo by: Nguyen Tai Thang ATP) To worsen the situation, the poachers have stealthy electrofished in both daylight and nighttime in spite of the ban in Circular No. 62/2008/TT-BNN of May 20 th, 2008 of the Minister of Agriculture and Rural Development on amendment and supplementation of Decree No. 59/2005/NĐ-CP of May 4 th, 2005 of the Government on conditions for production and trading of some fisheries industry. Electrofishing is able to cause mortality and internal injuries for the turtle and other aquatic species, particularly for fishes are spinal injuries, fracture vertebrae and associated hemorrhages, that directly threatens Dong Mo Rafetus, and declines its food source massively [34]. From the interviews, 48.57% of locals noticed the illegal electrofishing around the lake, for example, in Ngon Mua area, Ngon Muoi area, Dai Island chiefly in flood season, and the lake owner also electrofishes in March and April. Those electrofishing cases were mentioned by respondents in all 30

38 four communes proving that its range is extensive, but scattered and individual scale. In the case of being caught, sets of electrofishing equipment and boats were confiscated by the lake owner, sometimes the poachers were fined. However, the most recent confiscation of an electrofishing set by local fishermen was on April 11 st, 2015 added to the total reaching 11 confiscated sets [20]. Figure 8. Utilization of electrofishing (Photo by: Nguyen Tai Thang ATP) Even though R. swinhoei is known as large and strong species, it can be occasionally entangled in fishnet or trawl, and possibly get caught. The answers of fishermen in Kim Son Commune during interviews revealed that in the past, several impressively giant turtles with their strong physique used to frighten the fishermen whenever they approached and swung their boats, and they had to compete with this species for fish since those turtles ingested the large amount of fish and frequently stole fish in their nets, then broke them. Those were the reason why some fishermen captured them with fish hook lines or when they got entangled in fishnets. After the dramatic reduction in number, the remaining turtle seems to be afraid of fishermen while it now favors calm and deep zones, avoids regular fishing regions, and dives immediately in the case of detecting any boat close by during emerging for breath. Thus, fishing is likely to be a factor altering the behavior and habitat choice of the turtle. In addition, this activity may decrease the fish stock in Dong Mo Lake leading to the reduction in food source of the turtle based on the comments of fishermen about the difficulty in fishing and the decline of fish yields in recent years, and the judgment of the lake owner Mr. Tu natural fish stock is dropped by 31

39 30% to 40% compared to 15 previous years due to the anthropological overexploitation [16]. Furthermore, Dong Mo residents hunt birds and storks using net, trap and gun. The four eyed turtle (Sacalia quadriocellata) was also reported to be entangled in fishnets by a fisherman in Nghia Son Village, Kim Son Commune, then transferred to TCC in Cuc Phuong National Park by ATP staffs in June Hunting other species probably risks the survival of Swinhoe s softshell turtle in the lake whilst there is the worry that the turtle will be targeted if it shows up unwittingly in the sight of the poachers during hunting. There was an undesired incident on March 2 nd, 2015 when a man from Yen Bai Commune attempted to hunt bird at night, then he spotted the large turtle on the lakeshore and dragged it from the lake, put in the sack to bring back with the help of three other men. Fortunately, the turtle bit the bag and successfully escaped. After that, the Police and FPD were involved in the case [18]. Cases in nighttime are problematic because of no patrol of ATP counterpart and no support of local people in detecting and reporting for timely rescue. Plus, in dry season, the drastic decrease in water elevation of Dong Mo Ngai Son Reservoir with its function of supplying water resource for 958 hectare agricultural land increase the exposure of the turtle to the threat of hunting. For instance, from April 2 nd to April 6 th, 2010, the low water level meters continued to decline to meters which was only 51 centimeters away from the dead water level, the lake volume reduced to 5.9 million cubic meters corresponding to ca. 12% to 15% of its average storage capacity. The inhabitants could stroll and go fishing in many exposed lands after lake water receded dramatically which were used to be the lakebed [3]. The decrease in lake surface area not only cannot guarantee the environment for the Dong Mo Rafetus as well as other aquatic species, but also narrows its hidden places escalating the risk of being captured. About the education and communication, 100% of interviewees knew that electrofishing was prohibited and the users will be fined if they are discovered % of locals heard that the wildlife hunting should be restricted by local officials, but the another 48.57% had no information. The media, ATP educational activities, introduction board of Rafetus swinhoei on Kim Son levee, village meetings, education posters in village halls, commune loudspeakers provided the knowledge of the critically endangerment and protected under law status of this 32

40 turtle for 91.43% of inhabitants, only 8.57% did not access this information. The media was proved to be the most effective means since it was mentioned the most during the interviews, and ATP activities was the second one. The results show that wildlife hunting had not received the adequate concern and management, which possibly led to the overexploitation, fauna depletion and threat to the Swinhoe s softshell turtle. In contrast, the ban of electrofishing and the conservation of R. swinhoei are widely publicized that promotes the protection of the turtle, and reduces the risk to it and other aquatic animals in the lake. 5. Invasive alien species 5.1. Introduction of invasive alien species According to the International Union for Conservation of Nature (IUCN), an alien species is a species introduced by humans either intentionally or accidentally outside of its natural past and present distribution; nonetheless, approximately 5% to 20% of them cause the adversely impacts called invasive alien species. An invasive alien species as mentioned in the Convention on Biological Diversity is a species that is established outside of its natural past or present distribution, whose introduction and/or spread threaten biological diversity [40]. Also, the list of 100 of the World s Worst Invasive Alien Species was published by IUCN in 2000 to present the range of selected alien species with the ability of establishment, dominant in the new places leading to serious consequences for biological diversity and human activities. The Vietnam Ministry of Natural Resources and Environment and the Ministry of Agriculture and Rural Development jointly stipulated Interministerial Circular No. 27/2013/TTLT-BTNMT-BNNPTNT based on the Vietnam Biodiversity Law issued in 2008 on providing criteria for determination of invasive exotic species and promulgating the list of invasive exotic species. Invasive introduced species is defined as the species has established, overwhelmed invaded habitat, competes for food and harms the native species, has strong dispersal ability, tends to or is disrupting the ecosystem balance in where they introduced in Vietnam. Besides, the species, which has not established, tends to overwhelm invaded habitat, competes for food and harms the native species, is potentially invasive exotic species existing in Vietnam [42]. Invasive species are identified as the second most common threat associated with species that have gone completely extinct, and the most common threat associated with the extinction of amphibians, reptiles and mammals by the IUCN Red List [40]. In their new 33

41 ecosystems, invasive alien species possibly become predators, competitors, parasites, hybridizers, and diseases of native plants and animals Mimosa pigra Description Mimosa pigra is commonly known as Giant sensitive tree, Bashful plant, Catclaw mimosa, Black mimosa, or Mai dương. It is a species of the genus Mimosa, in the family Fabaceae. M. pigra is listed as one of the world s 100 worst invaders. Stems are greenish at young phase, then become branched woody with slightly recurved spines from 5 to 7 millimeters. The height of this species varies depending on their age with the average growth rate of 1 centimeter per a day. The 1 year plant reaches the height of to centimeters, the 2 3 years plant is to centimeters, the 4 5 years plant is 237 to centimeters, and the over 5 years plant is to centimeters. Bipinnate leaves are bright green, and have the length of 20 to 25 centimeters composing of ca. 15 pairs of 5 centimeter opposite primary segments of sessile, narrowly lanceolate leaflets. The pink or mauve, small flowers bloom into spherical clumps of 1 to 2 centimeters in diameter that borne on stalk 2 to 3 centimeters long with two in each leaf axil, and the corolla has 4 lobes with 8 pink stamens. The flattened pods are thick, hairy, each contain 20 to 25 seeds, and turn brown, break into one seeded segments when mature with the length of 6.5 to 7.5 centimeters and the width of 0.7 to 1 centimeter, which also grow in groups in the leaf axils. The seeds are brown or olive green, oblong, and flattened with the length of 4 to 6 millimeters and the width of 2 millimeters [24]. This species flourish quickly, and start to flower and sprout seeds in the first year from germination. Flowers are pollinated, fertilized by insects such as bees, butterflies and wind, and last for 7 to 9 days while the growth period of seed pods is 25 days. They are able to bloom and fruit throughout the year, but the peak period of blooming is February to July, and of fruiting is June to December also the rainy season. In one time of blooming, there are 6 to 11 bud clusters on each branch, only 1 to 3 buds of which develop flowers with ca. 125 single flowers among each clump. Then, each blossom clump becomes 2 to 14 fruits containing 6 to 18 seeds each. Their seeds protected by pods are extremely hardy, and can remain dormant for more than 15 years depending on the environment. Furthermore, M. pigra has high adaptability allowing them to tolerate drought and inundation in long time due 34

42 to the viability in anaerobic medium, and the development of lateral roots near water surface for oxygen uptake [14] Habitat Because of the preference for the wet dry tropical climate, open and humid sites, Mimosa pigra has grown densely along the edges of Dong Mo reservoir, especially, this lake becomes more ideal place for this species because of the characteristics of seasonally floodplain and high annual rainfall. Besides, they develop faster and tend to colonize in disturbed areas such as agricultural lands, planted forests, grazing lands, roadside, and residential since their seeds germinate better on bare soils without competitive pressures imposed by other seedlings. Figure 9. The dense growth of Mimosa pigra along shoreline Source of introduction Mimosa pigra is native to tropical America extending from Mexico through Central America to Northern Argentina. In the early 80s, they grew sporadically along rivers in some provinces of Southwestern Vietnam, along the edge of Tri An Lake in Dong Nai Province, and Dong Mo Lake in Ha Tay Old Province [22]. From the information of some locals in Kim Son Commune, in the period of to early 80s, Mr. Phuc duck, resident of Long Ho Village, Kim Son Commune, brought seeds of Mimosa pigra from Vinh Phuc Province back to hometown for the purpose of using as fence. After that, they spread widely in every corners of Dong Mo area, and began to break out in the early 90s. Their pathways are abundant: seeds are consumed and excreted by animals, or unintentionally transported by vehicles or within exploited soil, sand when the number of transportations and constructions has visibly increased; the seed pods attach to animals and human 35

43 clothing by the cover of bristles, or dispersed by wind and water currents. Fast moving water is probably the most important seed dispersal mechanism of this species since the seed pods are buoyant, and it is the effectively natural form of distribution [24]. All of those methods facilitates their long distance travel, and results in rapid spread Threat from Mimosa pigra to Rafetus swinhoei Being asked about M. pigra, for the group of 74 to 50 years long residents, 25% recognized it as invasive alien species, 12.5% mistook this plant as native species, and 62.5% cannot determine whether it is invasive or not. For the group of 49 to 25 years long residents, 45% recognized it as invasive alien species, 5% mistook this plant as native species, and 50% cannot determine whether it is invasive or not. For the group of below 24 years long residents, 14.29% recognized it as invasive alien species, 28.57% mistook this plant as native species, and 57.14% cannot determine whether it is invasive or not. Based on this classification, locals lived for 49 to 25 years in Dong Mo area have the most thorough indigenous knowledge to conclude the giant sensitive tree is invasive alien species. The group of below 24 years long residents with the least indigenous knowledge as expected get confused the most because of its naturalization which this plant has wild population independent of further human introductions. Surprisingly, 74 to 50 years long residents give the most unknown answers showing that they do not have adequate knowledge to decide. Besides, notably, 75% of interviewees who confirmed Mimosa pigra is invasive alien species are inhabitants of Kim Son Commune. This outcome supposes that citizens in Kim Son Commune are more aware of this invasive species and the lake than in Son Dong, Co Dong and Yen Bai Communes, and strengthen the information of locals about its source of introduction. From the results of interviews, 42.86% of locals supposed that the giant sensitive tree only affected the fishing job of locals that they have encroached the fishing zones, the fishnets are stuck and torn by thorns when fishermen try to catch fish and shrimp hiding in Mimosa bushes. 8.57% of interviewees chose the opposite side that this plant may cause wounds for the Rafetus turtle, but has no linkage to the fishing practices. 40% of opinions believed that the catclaw mimosa impacts on both fishing and the turtle with the combine of previous reasons and an addition which they prevent the turtle from climbing up onto the islands. The remaining 36

44 8.57% thought of no effect of this species on neither fishing nor the turtle. The outcome presents that Mimosa pigra did influence the fishing activities and the Rafetus swinhoei individual. The giant sensitive trees growing densely on lakeshore and the adjacent shallow water areas are similar to a barrier block the turtle s path to land for basking. Even where this invasive species sparsely distributed, if the turtle attempts to crawl onto the shore, their thorny stems and branches can scratch and injure the thin skin of the turtle leading to its avoidance of many ideal sunbathing sites. Mimosa clumps becoming the hidden places for fish and shrimp trouble the turtle to seek for a meal, and injure it if it approaches the thick plant zones when chasing prey Trachemys scripta elegans Description Trachemys scripta elegans is commonly known as Red eared Slider or Rùa tai đỏ. It is a semiaquatic turtle of the genus Trachemys, in the family Emydidae. T. s. elegans is listed as one of the world s 100 worst invaders. This species is a freshwater turtle with the carapace size of 125 to 289 millimeters. They are simply distinguished by the typical trait of small red stripes on each side of head, around their ears. The carapace is oval, flattened, and its color changes from leaf green in juvenile to olive and brown with yellow stripes and spots when mature. Males are usually smaller than females, and have longer, thicker tails. Their wild life spans are ca. 20 to 30 years, in some cases are over 40 years, and longer in captivity. Since this species is poikilotherm, they need to bask frequently to regulate their body temperatures. In the wild, red eared sliders brumate over the winter at the bottom of lake becoming inactive, and occasionally rise to the surface for food or air when the temperature drops very low. They are omnivore consuming a wide range of plants and animals including grass, filamentous algae, macrophites, frog eggs, tadpoles, snails, diptera (larvae and pupae), terrestrial insects, crustaceans and small vertebrates. The diet of adult contains less invertebrate than juvenile as they become more herbivorous. They reach sexual maturity in the third to fourth year when the carapace length of male is 10 centimeters and of female is 15 centimeters. Mating season occurs between March and July. To seek for spawning site on the shore of freshwater body, female can travel to the distance of 1.6 kilometers, and excavate the jug shaped nest up to 12 centimeters deep after choosing the ideal one. Six 37

45 clutches may be laid per year with ca. 6 to 11 eggs per clutch, and incubated in 59 to 112 days. At appropriate temperature of 22 o C to 30 o C, the hatching time takes 55 to 80 days. The eggs are oval, 31 to 43 millimeters in length, 19 to 26 millimeters in width, and 6.1 to 15.4 grams in weight. Sex of the embryos depends on temperature when hatchlings are only males in cool incubation temperatures of 22 o C to 27 o C, and only females in warmer temperatures [31] Habitat This species favors calm, warm water bodies with soft bottoms having plenty of aquatic plants and suitable basking sites such as riparian zones of lake. Dong Mo Lake has suitable conditions for the development of the red eared slider comprising spacious habitat with still water, and lots of islands and islets for sunbathing their essential needs. The particular places detecting the presence of this species are Dai and Ngan Islands, and Son Dong Dam. Figure 10.Trachemys scripta elegans in Dong Mo Lake (Photo by: Pham Van Thong ATP) Source of introduction Trachemys scripta is native to Eastern of America, and adjacent area of Mexico. It ranges from Virginia Southwestward through to Florida, Alabama, Mississippi, Louisiana, and Texas to Mexico. To the North, the distribution of T. scripta reaches through Kentucky and Tennessee to Ohio, Indiana, Illinois and 38

46 Iowa, and West to Kansas, Oklahoma and New Mexico. The subspecies Trachemys scripta elegans has Western and Central range occupying Mississippi Valley from Illinois via parts of Eastern New Mexico in the West to the Gulf of Mexico. Since the 1970s, turtle farms in America have supplied the sheer number of Trachemys juveniles for pet trade. The red eared slider has become the most popular and common pet with more than 52 million individuals exported from America to foreign markets in the period of 1989 to 1997 [31]. Locals around Dong Mo area suggested that the appearance of T. s. elegans in lake in the period of may originate from being released by owners when they lost their interest in keeping them as pet or cannot manage to take care of them in the adult stage, or by the monks and Buddhists after traditional mercy ceremony to increase good karma, honor Buddha and repent for sins Threat from Trachemys scripta elegans to Rafetus swinhoei Being asked about T. s. elegans, for the group of 74 to 50 years long residents, 100% cannot determine whether it is invasive alien species or not. For the group of 49 to 25 years long residents, 10% disagreed that the red eared slider is assigned as invasive alien species, and 90% cannot determine whether it is invasive or not. For the group of below 24 years long residents, 14.29% recognized it as invasive alien species, and 85.71% cannot determine whether it is invasive or not. The outcome reveals that in general, locals in all four communes have limited knowledge of red eared slider, and this species is newly introduced that the younger people is more aware of them than the old. The small amount of information about the red eared slider in Dong Mo Lake was collected since only 22.86% of interviewees with 14.29% in Kim Son Commune, 5.71% in Son Dong Commune and 2.86% in Co Dong Commune observed and had scarce knowledge about them. The another 77.14% never recognize any sign of this species. Although large bales of red eared sliders with ca. 10 to 20 each bale were reported around Ngan and Dai Islands, and the small dam in Son Dong Commune, their quantity across the lake is small showing no harm to other species in lake including the Swinhoe s softshell turtle from the locals view although they are omnivorous and consume the substantial amount of fish, grass, rice plants for meal. 39

47 6. Rank of threats Indigenous people were asked to score six factors considered as threat to the Rafetus swinhoei individual, and the results from addition of each threat are shown in Table 1. Table 1.Score calculation and rank of threats from local people opinions Threats Location Kim Son Son Dong Co Dong Yen Bai Total Rank Dong Mo Dam #5 Tourism developments #2 Fishing #3 Hunting #1 Mimosa pigra #4 Trachemys scripta elegans #6 40

48 Figure 11.Total scores of threats As shown in the Table 1, from locals opinions, the rank from threat #1 to #6 is hunting, tourism developments, fishing, Mimosa pigra, Dong Mo Dam, then Trachemys scripta elegans due to the descending order of points. Obviously, the hunting is the highest threat since the interviewees supposed that it is the most direct activity possibly causing the turtle s death. The local growing concern about the expansion and waste release of tourism developments is the reason why they are placed in the second position. Fishing with the dangerous techniques consisting of electrofishing, fish hook line and the past cases of turtle capture makes the inhabitants believe it is the third threat. The fourth one is M. pigra primarily because this plant can injure the turtle, and is likely to influence Hoan Kiem turtle more than the fifth Dong Mo Dam that the principal effect of it is to regulate the water elevation and is fairly irrelevant to the turtle in locals view, and the lowest threat T. s. elegans that the majority of indigenous people never observed and seems harmless with small population. From my own judgment, fishing should be the highest threat to the turtle because of the high frequency and the direct impact on the its viability as well as food source. The second one is Dong Mo Dam for the reason that it can cause the death or injuries, or open the escape path from protected lake for the turtle despite only in rainy season. The other lethal factor is hunting, but it is placed in the third position due to the lower probability. The large scale occupation of lakeshore and 41

49 encroachment of lake surface area which narrows the choice of basking and nesting sites, the surface water disturbing activities, and the possibly mental influence qualify tourism developments as the fourth spot. The fifth threat is M. pigra since it is the dense barrier obstructing the turtle from reaching land, and can cause external wounds for it with their prickles. T. s. elegans is the lowest threat because of their small population across the lake in the interim. In addition, based on the map of Rafetus swinhoei observation location from ATP, observations of ATP staffs and locals were recorded frequently near the Kim Son and Son Dong residential area, Xiet Island, Con Ma and Gieng Hills, and sparsely near the Dong Mo Dam, King s Island Golf Course. That proves this order is also compatible with the usual habitat of the turtle that the closer the threat to its habitat, the more it affects. Finally, the order from #1 to #6 is fishing, Dong Mo Dam, hunting, tourism developments, Mimosa pigra, Trachemys scripta elegans. Figure 12.Map of Rafetus swinhoei observation location in Dong Mo Lake (Source: ATP) 42

50 7. Conservation value of Dong Mo Lake Based on the data from two previous studies Điều tra, đánh giá đa dạng sinh học động vật có xương sống ở cạn đập chứa nước Đồng Mô Ngải Sơn, Hà Nội and Điều tra, đánh giá về đa dạng sinh học cá ở khu vực đập Đồng Mô Ngải Sơn, Hà Nội, the list of mammals, birds, reptiles and fishes listed in IUCN Red List or Vietnam Red Data Book, or protected under Vietnam Law is clarified and categorized [8, 10]. One critically endangered species, and three vulnerable species are listed in IUCN Red List. In Vietnam Red Data Book, there are one critically endangered species, three endangered species, and one vulnerable species. Seven species are classified in Group II B in Decree 32/2006/ND-CP. The thirteen animals boost the conservation value of Dong Mo Lake, in terms of genetic resources, biodiversity protection, and tourism attraction. Table 2.List of Mammals, Birds, Reptiles, Fishes and their conservation status in Dong Mo area Conservation Status No. Vietnamese Name Scientific Name IUCN Red List 2016 Vietnam Red Data Book 2007 ND 32/2006 A. LỚP THÚ MAMMALIA BỘ ĂN THỊT Họ Cầy CARNIVORA Viveridae 1 Cầy hương Viverricula indica II B B. LỚP CHIM AVES BỘ VẸT PSITTACIFORMES 1. Họ Vẹt Psittacidae 2 Vẹt đầu hồng Psittacula rosecta II B 3 Vẹt ngực đỏ Psittacula alexandri II B 2. Họ Cú Lợn Tytonidae 4 Cú lợn lưng xám Tyto alba II B 43

51 C. LỚP BÒ SÁT REPTILIA I. BỘ CÓ VẢY SQUAMATA 1. Họ Rắn Nước Colubridae 5 Rắn sọc dưa Elaphe radiata VU II B 6 Rắn ráo thường Ptyas korros EN 2. Họ Rắn Hổ Elapidae 7 Rắn cạp nong Bungarus fasciatus EN II B 8 Rắn hổ mang Naja naja II B II. BỘ RÙA Họ Ba Ba TESTUDINES Trionychidae 9 Giải Thượng Hải Rafetus swinhoei CR CR 10 Ba ba trơn Pelodiscus sinensis VU D. LỚP CÁ OSTEICHTHYES I. BỘ CÁ CHÉP CYPRINIFORMES Họ Cá Chép Cyprinidae 11 Cá trôi Mrigal Cirrhinus cirrhosus VU II. BỘ CÁ NHEO SILURIFORMES Họ Cá Ngạnh Cranoglanididae 12 Cá ngạnh Cranoglanis bouderius VU III. BỘ CÁ VƯỢC PERCIFORMES Họ Cá Chuối Channidae 13 Cá chuối hoa Channa maculata EN 44

52 Note: CR: Critically Endangered; EN: Endangered; VU: Vulnerable; II B: Group II B (restricting exploitation and use for commercial purposes) issued in Decree 32/2006/ND-CP by Vietnam Government. 8. Discussion In spite of the adverse effect on the Dong Mo Rafetus, the role of the dam is essential in regulating lake water. It irons out hydrological extremes by storing floods, and provides water for irrigation that prevents flood from destroying crop fields of local farmers and tourism infrastructures. Moreover, the Lake Management Authority can monitor, control and regulate the water level to avoid frequent water discharge, and the situation of excessive or deficient volume of water in lake. Despite the lack of proof of pollution caused by the Golf Course, there are several prior studies all over the world about the impacts of chemicals usage of golf courses that provide the connection and assumption about the case of King s Island Golf Course in Dong Mo area. The evaluation of the fate of fertilizer applied to turfgrass was carried out in the Clearwater Bay Golf and Country Club in Hong Kong. The results from reconstituted soils collected from fairways and greens with Bermudagrass showed that the application rate on greens would adversely environmental impact on the surface water and groundwater quality due to leaching loss of PO4 3- and NO3 - since their concentration in leachate of greens exceeded the surface water standard [38]. Another investigation was conducted at 5 golf courses in southeastern North Carolina, America to determine levels of pollutants contributed by the courses to adjacent coastal streams. Nitrate levels in the outflow streams were at or above concentrations causing significant increases in phytoplankton biomass. These coastal creeks host spring and summer algal blooms; thus, some golf course discharge nutrient concentrations are at levels great enough to contribute to eutrophication problems in estuarine waters [32]. If the water contamination and eutrophication happen in Dong Mo Lake, they will extremely diminish the habitat, living condition and food quality of the turtle and other aquatic organisms. 45

53 Figure 13.Maintenance activities of Golf Course Fishing undoubtedly causes fundamental influences on R. swinhoei; however, the helpful support of fishermen is undeniable. The information about regular locations of the Rafetus turtle has been contributed by their observations during going fishing. That valuable information and the indigenous knowledge of its behavior, dietary preference which are deficient benefit the observation, protection and habitat improvement from prioritizing the key zones, and documenting extra natural characteristics. Moreover, after signing the no hunting agreement, they have assisted ATP staffs in detecting, removing fish hook lines floating on the lake to avoid the damage to the turtle, and reporting illegal electrofishing cases. In addition, the annual release of juveniles by the lake owner partly offsets the fish stock loss, and fishermen can only catch the specific type of fish in their contracts with the lake owner that mitigates the impact on fish resource. The interviewees shared that the main object of hunting was birds, but other animals can also be the target in reality. Excluding the critically endangered Rafetus swinhoei, other vulnerable, endangered and protected species in Table 2 are threatened by hunting. Although fish and shrimp hiding in Mimosa pigra bushes troubles the fishermen and the preying of the Rafetus turtle, they create a temporary habitat for them supporting their breeding, development, and protecting them from fishing that 46

54 may increase the turtle s food source. In regards to the small quantity of Trachemys scripta elegans, their time since introduction is ca. 5 to 7 years which is short compared to the giant sensitive plant; therefore, they may have been in progress of development. The lady in Long Ho Village, Kim Son Commune shared that bales of red eared sliders around Ngan and Dai Islands are all small sized individuals. There are two possibilities that they are juveniles added by human release, or the result of previous generations mating and reproduction. Both scenarios support the assumption that their population is expanding. If they develop on their own without any intervention, they will have the opportunity to become the uncontrollable invader. The ability of competition for food, nesting and basking sites of T. s. elegans is proved by their occupation of better basking sites in Europe forced the endangered European pond turtle (Emys orbicularis) to sunbath in lower quality places, and in America, they posed a threat to the Pacific pond turtle (Clemmys marmorata), a declining endemic species to the Pacific states. Parasite transferring from red eared slider to European pond turtle and Mediterranean pond turtle (Mauremys leprosa) may impact the survival of those native species in Europe. In Paris, this species was revealed to consume both aquatic plants and animals [31]. Furthermore, in International workshop on the Conservation of Hoan Kiem turtle, Hanoi in 2011, many scientists suggested that the red eared sliders in Hoan Kiem Lake attacked, infected the Hoan Kiem turtle with disease resulting in injuries and ulcers on its skin and carapace, and competed for food. Regardless of the difference in size between Hoan Kiem Lake and Dong Mo Lake, they are potentially the competitor and disease carrier to the Dong Mo turtle when achieving the crowd population. Overall, this matter should not be overlooked as the prevention is more cost benefit than elimination afterward. VI. Conclusion Dong Mo Ngai Son Reservoir is a large lake in Son Tay District, on the outskirts of Hanoi City. It is also home of the only known wild Rafetus swinhoei individual. This species is on the verge of extinction that it is listed as critically endangered in IUCN Red List, Vietnam Red Data Book, and protected under Vietnam strict law the same as tiger and elephant. Nonetheless, living in the extensive lake and surrounded by human developments and exploitation, threats apparently have been existing to the turtle. 47

55 - Spillways of Dong Mo Dam create the escape way for the turtle from the protected lake, and the bottom outlets can trap it when they are opened. - The development of tourism constructions narrows the habitat, basking and nesting sites of the turtle; surface water recreation disturbs the aquatic environment, and can cause wounds for it; the emission of artificial lights at night and noise influence the behavior of the turtle. - Dangerous fishing techniques injure and threaten the existence of R. swinhoei individual; fishing reduces its food source, and may affect its behavior; hunters can capture the turtle when poaching other species. - The dense growth of Mimosa pigra along shoreline hinders the turtle from sunbathing, and injures it with their thorny stems; Trachemys scripta elegans is potential competitor and disease carrier to the turtle. In conclusion, although the Rafetus swinhoei individual is protected in Dong Mo Lake with the great deal of effort of the non governmental organization Asian Turtle Program, local administration, and inhabitants, threats to the turtle have still existed influencing its viability, habitat and food source. There is the need of remedies that not only enhances the conservation acts of this rare species, but also do not suppress the area development. VII. Recommendations - Build the permanent steel fence with concrete piles beyond the dam to secure the turtle in protected lake, and reduce the risk of Dong Mo Dam. - Monitor the land reclamation of the Golf Course, construction activities of other development projects, proposals for developing land areas surrounding Dong Mo Lake, and consider carefully proposals using shoreline before authorizing building permits. - Require all tourism motorboats and motor canoes to equip propeller guards, and restrict the area of their activities. - Collect the lake water samples and analyze to assess the water quality, especially around the Golf Course. Local administration should occasionally inspect and monitor their utilization of pesticides, fertilizers to limit the possible impacts. 48

56 - Expand the no fishing zones in Dong Mo Lake. - Educate inhabitants on the consequences of fish hook line, electrofishing and hunting for the R. swinhoei individual and other animals, and the need of limiting or stopping the usage of dangerous fishing techniques and wildlife poaching. - Organize village patrol teams to monitor and report illegal fishing and hunting. - Apply more potentially physical, chemical and biological methods for eradicating Mimosa pigra to replace ineffective methods used by locals, which comprise of pulling, cutting, then burning or spraying herbicides. Physical methods: cut, remove and burn flowers, seed pods; plant competitive plant species such as rice, peanut, potato; remove and destroy roots (blade ploughing). Chemical methods: apply allowed herbicides during the active period of growth of this species and before any seed mature. Biological methods: control agents, for example Acanthoscelides puniceus and A. quadridentatus, cause damage to parts of plant naturally, but should be selected cautiously to avoid the damage to other non target plants or other potential invasive species. Nevertheless, physical methods showing low efficiency should be applied with other chemical or biological methods, and chemicals should be restricted since they can contaminate the lake water, and adversely impact on the endangered turtle. Biological methods are strongly recommended because of their environmentally friendly approaches. - Monitor the population of Trachemys scripta elegans to control and prevent them from establishment. Sliders can be captured by fishnet or through various trapping devices. Their eggs can be found and removed by following females at nesting areas. - Educate the local people on the invasive alien species and their tremendous impacts to avoid or limit the addition of existed exotic species, and the intentional or accidental introduction of new ones in Dong Mo area. - Increase educational programs, articles, update news about Rafetus swinhoei on the media to raise public awareness, and attract the donation, support for future ATP education and conservation activities. 49

57 - Create more ideal basking and nesting sites for the turtle improve its living conditions, and examine the number of individuals in the lake. - If the searching efforts are paid off that another Rafetus swinhoei individual is found, it should be transferred to Dong Mo Lake to cohabitate or mate with the existing male, and the establishment of Nature Reserve in Dong Mo area should be considered as the gathering place of this critically endangered species and protection region of other organisms listed in IUCN Red List, Vietnam Red Data Book, and Vietnam law that facilitates the conservation acts and saves the investment. Reference Vietnamese 1. Cao Thị Dung (2015), Tiểu luận bảo tồn loài rùa quý hiếm nhất trên thế giới tại Việt Nam Rùa Hoàn Kiếm, Trường Đại học Sư phạm Hà Nội. 2. Đoàn Văn Tiến (2010), Hãy giữ nước Đồng Mô để bảo vệ rùa khổng lồ, Báo Thể thao và Văn hóa. 3. Đỗ Minh, Phạm Hải (2010), Hồ Đồng Mô (Hà Nội): Hồ Hà Nội khô cạn lịch sử, Báo Vietnamnet. 4. Hương Thu (2011), Họ hàng của Rùa Hồ Gươm có nguy cơ mất tích, Báo VnExpress. 5. Lê Đình Thủy (2004), Nghiên cứu, đánh giá hiện trạng và sử dụng bền vững đa dạng sinh học lưu vực hồ chứa Đồng Mô - Ngải Sơn phục vụ phát triển kinh tế - xã hội, Báo cáo tổng kết đề tài, Viện Khoa học và Công nghệ Việt Nam. 6. Lưu Lan Hương (2012), Đánh giá tính đa dạng của thực vật bậc cao có mạch tại khu vực Đồng Mô - Ngải Sơn, thành phố Hà Nội, Báo cáo chuyên đề. 7. Nguyễn Chí Thành (2011), Nghiên cứu tính đa dạng của Khu hệ chim tại Khu bảo tồn thiên nhiên Ngọc Sơn Ngổ Luông, tỉnh Hòa Bình. 8. Nguyễn Huy Hoàng (2012). Điều tra, đánh giá đa dạng sinh học động vật có xương sống ở cạn đập chứa nước Đồng Mô Ngải Sơn, Hà Nội, Khoa Sinh học, Trường Đại học Khoa học Tự nhiên (ĐHQGHN). 9. Nguyễn Thị Duyên (2010), Tìm hiểu hoạt động du lịch tại Làng Văn hóa du lịch các dân tộc Việt Nam, Đồng Mô, Sơn Tây, Hà Nội, Khóa luận tốt nghiệp, Trường Đại học Khoa học Tự nhiên (ĐHQGHN). 50

58 10. Nguyễn Thành Nam (2012), Điều tra, đánh giá về đa dạng sinh học cá ở khu vực đập Đồng Mô Ngải Sơn, Hà Nội, Trường Đại học Khoa học Tự nhiên (ĐHQGHN). 11. Nguyễn Tài Thắng (2015), Xây dựng bãi đẻ cho loài rùa hiếm nhất thế giới, Asian Turtle Program. 12. Nguyễn Tài Thắng, Timothy McCormack (2015), Thêm một khu vực tiềm năng cho Rùa Hoàn Kiếm được phát hiện tại Việt Nam, Asian Turtle Program. 13. Nguyễn Thanh Thùy, Phát triển du lịch sinh thái tại khu du lịch Đồng Mô (Sơn Tây Hà Nội), Khóa luận tốt nghiệp, Trường Đại học Dân lập Hải Phòng. 14. Phạm Văn Lầm, Phạm Bình Quyền (2010), Cây trinh nữ đầm lầy (Mimosa pigra L.) loài ngoại lai xâm lấn rất khó phòng trừ, mối đe dọa đa dạng sinh học, Hội thảo khoa học, Hội Bảo vệ thiên nhiên và Môi trường Việt Nam. 15. Phạm Văn Thông, Timothy McCormack (2013), Mở cửa đập hồ Đồng Mô: Nguy cơ tiềm ẩn với công tác bảo tồn loài rùa Hoàn Kiếm, Asian Turtle Program. 16. Phạm Văn Thông, Timothy McCormack (2015), Thiết lập vùng cấm đánh bắt cá để bảo vệ loài rùa quý hiếm nhất trên thế giới, Asian Turtle Program. 17. Phạm Văn Thông (2016), Lưới chắn rùa trên hồ Đồng Mô được thay mới, Asian Turtle Program. 18. Phạm Văn Thông (2016), Hoạt động nghiên cứu và bảo tồn Rùa Hoàn Kiếm tại Hồ Đồng Mô, Hội thảo Xây dựng chương trình quốc gia về bảo tồn rùa cạn và rùa nước ngọt nguy cấp Việt Nam, ppt. 19. Timothy McCormark (2012), Cần hành động bảo vệ nơi sinh sống hoang dã của loài rùa nguy cấp nhất Thế giới, Asian Turtle Program. 20. Timothy McCormack, Phạm Văn Thông (2015), Câu trộm trên hồ Đồng Mô đe dọa loài rùa nguy cấp nhất thế giới, Asian Turtle Program. 21. Viengsavanh Chanthabounheuang (2016), Nghiên cứu tình trạng và phân bố của rùa tại tỉnh Hùa Phăn, Nước CHDCND Lào, Luận văn thạc sĩ, Trường Đại học Lâm nghiệp. 22. Võ Văn Phú (2008), Quản lý loài ngoại lai xâm hại môi trường, Tạp chí Nghiên cứu lập pháp số 133 tháng 10 năm English 23. Benjamin S. H., Kimberly A. S., Fiorenza M. and Carrie V. K. (2007), Evaluating and Ranking the Vulnerability of Global Marine Ecosystems to Anthropogenic Threats, Conservation Biology, 21 (5), pp

59 24. Colin W., Parks, Wildlife Commission of the Northern Territory, IUCN/SSC Invasive Species Specialist Group (ISSG) Palmerston (Australia) and Annie L., Northern Department of Primary Industry and Fisheries, Resource Management Division, Australia (2006), Mimosa pigra (shrub), Global Invasive Species Database. 25. Doğa Derneği (BirdLife International), Association Les Amis des Oiseaux, BirdLife Global Secretariat, BirdLife International Middle East Division, IUCN, Plantlife International, Royal Society for the Protection of Birds, Sociedad Española de Ornitología, Sociedade Portuguesa Para O Estudo Das Aves, The Cirrus Group, and Tour du Valat (2010), Mediterranean Basin Biodiversity Hotspot Ecosystem Profile, pp , Critical Ecosystem Partnership Fund. 26. Douglas Hendrie (2009), Close call for the world's last R. swinhoei in the wild, Turtle Survival Alliance. 27. David S. W., David R., Jason D., Ali P. and Elizabeth L. (1998), Quantifying threats to imperiled species in the United States, BioScience, 48 (8), pp , American Institute of Biological Sciences. 28. Fisheries and Oceans Canada (DFO) (2014), Guidance on Assessing Threats, Ecological Risk and Ecological Impacts for Species at Risk, DFO Canadian Science Advisory Secretariat Science Advisory Report 2014/ George W. B., Rick A. D., John B. L., C Max F. and David J. W. (2001), Inventory and risk assessment of water dependent ecosystems in the Daly basin, Northern Territory, Australia, Supervising Scientist Report 162, Supervising Scientist, Darwin NT. 30. Howard Goldstein (2016), Rafetus swinhoei update, Turtle survival alliance. 31. IUCN SSC Invasive Species Specialist Group, Overseas Territories Environmental Programme and Cayman Islands Government - Department of Environment (2010), Trachemys scripta elegans (reptile), Global Invasive Species Database. 32. Michael A. M., Tracey L. W. (1999), Nutrient and Fecal Coliform Discharge from Coastal North Carolina Golf Courses (abs), Journal of Environmental Quality, 29 (3), p Paul Vander Schouw (2016), How to care for softshell turtles, Reptile Magazine. 34. Snyder D.E. (2003), Electrofishing and its harmful effects on fish. Information and Technology Report , U.S. Geological Survey. 35. Scott Duke Harris (2016), Turtle is legendary in Vietnam, but it's on the verge of extinction, Los Angeles Times. 52

60 36. Son Tay People s Committee (2010), Dong Mo 2010 Tourism Plan. 37. Timothy McCormack (2016), The death of the Hoan Kiem Turtle, Hanoi Vietnam - Farewell to a legend, Asian Turtle Program. 38. Wong J.W.C., Chan C.W.Y., Cheung K.C. (1998), Nitrogen and Phosphorus Leaching from Fertilizer Applied on Golf Course: Lysimeter Study (abs), Water, Air, & Soil Pollution (1998), pp Website 39. Ecological Risk Assessment. Retrieve from: Invasive species. Retrieve from: Kings Island Golf Resort. Retrieve from: Thông tư liên tịch 27/2013/TTLT-BTNMT-BNNPTNT của Bộ Tài nguyên và Môi trường Bộ Nông nghiệp và Phát triển nông thôn. Retrieve from: mode=detail&document_id= Appendix Appendix 01: Questionnaire for inhabitants in Kim Son, Son Dong, Co Dong, and Yen Bai Communes BẢNG CÂU HỎI PHỎNG VẤN ĐÁNH GIÁ CÁC MỐI ĐE DỌA ĐẾN HỆ SINH THÁI ĐỒNG MÔ, ĐẶC BIỆT LÀ ĐẾN CÁ THỂ RAFETUS SWINHOEI Mẫu bảng câu hỏi Thông tin cơ bản Ngày: Giờ PV số:... Địa chỉ:... Tên:.. Giới tính (khoanh): Nam Nữ Tuổi:... Nghề nghiệp:... 53

61 Dân tộc:... Cần có GPS cho mỗi PV 01. Các bác sống ở khu vực này bao nhiêu năm rồi? a. > 75 b c d. < Các bác có làm nghề đánh cá, săn bắt thú không? a. Có ( Đánh cá / Săn thú ) b. Không Nếu có thì làm bao nhiêu năm rồi? a. > 20 b c d. 9 5 e Các bác đã nhìn thấy rùa Hoàn Kiếm nổi lên bao giờ chưa? a. Có b. Chưa Nhìn thấy ở đâu, vào thời điểm nào? Đập cống tràn xây năm 2009 có ảnh hưởng gì đến hồ không? a. Có b. Không c. Không biết Lí do:... Đập cống tràn có phải mối đe doạ đến loài rùa Hoàn Kiếm không? a. Có b. Không c. Không biết Lí do: Việc xây dựng sân gôn và các khu du lịch, nghỉ dưỡng có phải mối đe dọa đến môi trường sống của rùa Hoàn Kiếm và các loài động vật hoang dã khác không? a. Có b. Không c. Không biết Lí do: Những phương pháp đánh bắt cá, tôm thường hay sử dụng là gì? (vd: lưới, câu, đánh bống, đó tôm, kích điện, câu giăng, úp, vét, đâm giáo) - Cá:... - Tôm: 07. Bác có biết dùng kích điện bị cấm không? a. Có b. Không Bác có thấy ai dùng kích điện không? a. Có b. Không Nếu có thì ở khu vực và thời điểm nào?. Họ bị xử lí như thế nào khi bị bắt? Những loài cá nào hay bắt được? Khoảng thời gian nào là bắt được nhiều cá, tôm nhất?... 54

62 Sản lượng cá, tôm khoảng bao nhiêu kg (tấn) mỗi ngày? - Cá: - Tôm: 09. Chủ hồ có bao giờ thả cá con hay cá mới vào hồ không? a. Có b. Không c. Không biết Liệt kê:. 10. Ngoài đánh bắt cá, tôm, người dân còn bắt các loài động vật nào khác? (vd: rùa Hoàn Kiếm, ba ba, chim, thú). Nêu rõ phương pháp (vd: câu giăng, kích điện, súng thể thao) Liệt kê:. 11. Từng thấy rùa Hoàn Kiếm bị bắt chưa? a. Có b. Chưa Thời điểm:... Phương pháp bắt:. Số lượng cá thể bị bắt:. Mục đích (ăn thịt hay bán):. Giá bán: Các phương pháp đánh cá của người dân có phải mối đe dọa đến rùa Hoàn Kiếm không? a. Có b. Không c. Không biết Nếu có thì phương pháp nào?.. Lí do: Các phương pháp đánh cá của người dân có phải mối đe dọa đến loài ba ba không? a. Có b. Không c. Không biết Nếu có thì phương pháp nào?.. Lí do: Khu vực Đồng Mô có loài thực vật ngoại lai nào không? a. Có b. Không c. Không biết Nếu có thì là loài nào?. Cây. gây hại hay có lợi? a. Gây hại b. Có lợi Lí do:... Cây. gây hại hay có lợi? a. Gây hại b. Có lợi 55

63 Lí do: Khu vực Đồng Mô có loài cá hay động vật ngoại lai nào không? a. Có b. Không c. Không biết Nếu có thì là loài nào?. Con. gây hại hay có lợi? a. Gây hại b. Có lợi Lí do:... Con. gây hại hay có lợi? a. Gây hại b. Có lợi Lí do: Theo bác, cây mai dương có phải loài ngoại lai xâm hại không? a. Có b. Không c. Không biết Cây mai dương xuất hiện từ khi nào?. Nguồn gốc:.. Khu vực xuất hiện nhiều: Thời điểm phát triển nhất:... Số lượng có tăng nhanh qua các năm không?. Người dân có sử dụng vào mục đích gì không? Cây mai dương: - Ảnh hưởng việc đánh bắt cá, tôm của người dân không? a. Có b. Không c. Không biết Lí do:. - Ảnh hưởng rùa Hoàn Kiếm không? a. Có b. Không c. Không biết Lí do:. 18. Những phương pháp diệt trừ cây mai dương người dân đã sử dụng? Liệt kê:. Hiệu quả:. 19. Theo bác, rùa tai đỏ có phải loài ngoại lai xâm hại không? a. Có b. Không c. Không biết Rùa tai đỏ xuất hiện từ khi nào?.. Nguồn gốc:.. Số lượng (địa điểm, thời điểm):.. Số lượng có tăng nhanh qua các năm không?. 20. Rùa tai đỏ có ảnh hưởng đến hệ sinh thái không? 56

64 - Tranh giành thức ăn với các loài khác (ăn tạp): - Ăn thịt cá tự nhiên (cá bản địa): - Rùa Hoàn Kiếm (tấn công): Những phương pháp diệt trừ rùa tai đỏ người dân đã sử dụng? Liệt kê:. Hiệu quả:. 22. Các cán bộ xã có tuyên truyền việc hạn chế bắt động vật hoang dã không? a. Có b. Không Có tuyên truyền tác hại của kích điện và biện pháp xử phạt người vi phạm không? a. Có b. Không 23. Các bác có biết loài rùa Hoàn Kiếm được pháp luật bảo vệ không? a. Có b. Không Biết qua phương tiện nào? Cho điểm từ 1-6 các yếu tố tác động đến rùa Hoàn Kiếm (điểm 6 cho yếu tố tác động lớn nhất, điểm 1 cho yếu tố ít tác động nhất) Đập cống tràn Sân gôn và khu du lịch, nghỉ dưỡng Đánh bắt Săn bắt Cây mai dương Rùa tai đỏ Appendix 2: Some additional photos Interview photos (Photo by: Chu Thanh Thao) 57

65 Left: The Swinhoe s softshell turtle in Dong Mo Lake emerged its head (Photo by: Nguyen Xuan Thuan ATP) Right: The dam collapsed in 2008 (Photo by: Timothy McCormack ATP) Left: A Chinese softshell turtle (Pelodiscus sinensis) entangled in fishnet (Photo by: Pham Van Thong ATP) Right: Capture two Chinese softshell turtle (Pelodiscus sinensis) (Photo by: Nguyen Tai Thang ATP) 58

66 Left: The Swinhoe s softshell turtle broke the fishnet (Photo by: Pham Van Thong ATP) Right: One of three men who attempted to capture the Dong Mo Rafetus in 2015 pointed the location of the turtle (Photo by: Pham Van Thong ATP) Left: Map of locations of recorded fish hook lines (Source: ATP) Right: Map of no fishing zones in Dong Mo Lake (Source: ATP) 59

67 Left: Fishermen signed the no hunting agreement (Photo by: ATP) Right: The boat race on July 3 rd, 2015 to improve the inhabitants awareness (Photo by: Nguyen Tai Thang ATP) Left: Football match organized to support the conservation of Swinhoe s softshell turtle (Photo by: Nguyen Tai Thang ATP) Right: The educational board about Rafetus swinhoei on Kim Son levee 60