Most of the extraordinary biodiversity richness of South-East Asian countries is concentrated in the national parks and other Protected Areas, with species-rich turtle communities surviving mostly in these reserves where their natural habitats are better preserved. However, very few studies have documented the turtle species richness of the various Protected Areas in Vietnam, which is not only one of the hotspots of chelonian diversity in the world but also one of the countries where their exploitation is the highest. Here, the diversity of turtles is studied in the Bach Ma National Park in central Vietnam, mainly characterised by forested hills and mountains, with ponds and streams of various shapes and structures. The study was carried out by conducting (i) semi-structured interviews of hunters recruited through a snow-ball procedure in local villages, (ii) inspection of turtle individuals in their hands, (iii) field surveys along random transects inspecting the various microhabitats used by these reptiles. We observed a total of 15 species, out of which 14 (93.3%) are threatened, based on IUCN Red List. A natural hybrid of Cuora bourreti × C. mouhotii obsti (Cuora «serrata») was observed. Three species (Cuora bourreti, Manouria impressa, Platysternon megacephalum) were the most frequently encountered species according to our interviewees. We conclude that, in order to enhance the conservation status of the turtle communities at the local level, it would be important (i) to increase the number of rangers patrolling the study area in the rainy season (from April to September) and (ii) to list the hunter's names in the villages surrounding the Bach Ma National Park and to convince them to sign an agreement with the local authorities to avoid hunting turtles within the Protected Area.

Breeding turtles in farms for offering them in the food market is a profitable market in Vietnam. Here we study, through structured questionnaires with 73 owners of turtle farms, the social and economic contexts of this business activity. We also collected ecological data for the most intensely bred species, the Wattle-necked softshell turtle, Palea steindachneri. Palea farms were typically small family-owned companies, with just 1 to 4 employees working just 1 - 2 h per day but almost every day in the week, and with 1 to 4 ponds available in the facilities. Sex ratio of farmed turtles was heavily skewed to females in both P. steindachneri and Amyda cartilaginea (the secondly most frequently bred species), and their clutch size was very similar. Inside farms, mating of P. steindachneri occurred in February, egg deposition in March - July with a peak in May, and egg hatching in May - October, with a peak in July. In Vietnam, the typical owner of P. steindachneri farms is a self-made man who had enjoyed very little management and support from government for his/her business.

Trade of turtles, for both food and pet, represents a substantial business in Vietnam, especially because this country is a cross-bridge for wildlife trade from Indochina to China. Vietnam is also one of the main countries worldwide in terms of the number of Facebook members, and a considerable portion of the business has gone online through Facebook trading, including turtle trade. Here, the advertisements of turtles for sale in Vietnamese Facebook groups were monitored for the period 2013-2018, obtaining a total of 481 advertisement cases concerning 5,758 individuals belonging to 53 species and 12 families. There has been a rapidly rising trade of turtles online, especially in the last two years. Many traded species were allochthonous, but native species accounted for 22 species and over 36 % of the traded individuals. Most allochthonous species were traded as hatchlings and juveniles, whereas most of the native species were traded as subadults and adults, thus suggesting a high frequency of illegal trade in wild caught animals. Five traded native species are considered among the 50 most threatened turtle species in the world. Turtle trade occurred mostly in the two biggest cites of Vietnam (Ho Chi Minh city and Hanoi), which accounted for 68 % of the total trade. Turtle price varied substantially across species and by different lifestages (i.e. hatchlings, juveniles, sub-adults and adults), and increased considerably in comparison to 1993 estimates.