The trade in turtles and tortoises, most of which have been captured in the wild, has become massive. Turtles are taken for their flesh and the shells; their eggs are also often taken. Certain species are taken for the pet trade, often as hatchlings. Turtles are speared, netted, trapped, caught with hook and line, and dug out of the mud during low water periods or while aestivating. Dogs and pit traps are used for many of the forest floor dwelling turtles. Riverine turtles may be captured on lines using baited straight pins.
A recurring pattern is for collection and export operations to become established at a particular location, collecting turtles through an extensive network of trappers, hunters and middlemen. This is by no means limited to professionals. In the villages and hamlets of the Asian countryside, "pet shops" purchase animals of all sorts from the local peoples. From these shops the turtles and tortoises make their way to the middlemen who then transport them across borders if necessary into the larger Asian and Chinese cites.
Transport by air is preferred, because the quality and survival rate of the traded turtles is optimal. Usually mislabeled as seafood, the turtles and tortoises are stacked in wooden crates violating international shipping regulations. Land routes are used where trails, roads and border crossings exist, and some shipments are made by river boat or by sea. These journeys can take up to several weeks. The trade in turtles is brisk, highly developed and ignored by border guards, customs officials and airline personnel on both the export and import sides of the Asian borders.
Collection efforts and capture and export volumes increase rapidly, reach a peak and then decline as accessible populations become depleted and collectors need to venture into new, more distant areas. There is also a corresponding decline in the average size of animals that are traded. Such 'boom-and-bust' cycles at particular locations have been noted for species such as Callagur borneoensis, Indotestudo forstenii, Manouria emys and Cuora amboinensis in Indonesia and Morenia petersi, Geoclemys hamiltonii, Hardella thurjii and Indotestudo elongata in Bangladesh.
The collection of turtles as pets usually involves different species to those used for their flesh or parts. Preferred species in the pet trade from Asia are rare and unusual species, such as Indian Star Tortoises Geochelone elegans, Australasian snake-necked turtles of the genus Chelodina and Pig-nosed Turtles Carettochelys insculpta. In addition, hatchlings and juveniles of other species from throughout the region are traded internationally in large numbers. Because pet turtles have a particular value per specimen, pet traders prefer small specimens that are easier and cheaper to ship. Almost all international trade is by air. The market for the relatively expensive Asian species and very expensive Australasian species is limited and partly illegal, but still involves hundreds to thousands of individuals for certain species per year, and may be significantly higher for hatchling Pig-nosed turtles.
In North Africa, the Middle East and Asia, threats to tortoises and terrapins are their used in traditional medicine and magic. Whilst their flesh is considered "unclean" for routine human consumption under Islamic tradition, their eggs and flesh may be consumed as a medication for stomach complaints or as a treatment for fevers. The blood of a tortoise is also believed to be a cure for warts. Some cultures fear tortoises, which are often killed whenever found, usually by crushing with a heavy rock. However, the numbers utilized in this way in North Africa are limited compared to their exploitation for tourist souvenirs, of which they form the major part of the market. Two particular forms of utilisation are especially common: decorative fire-bellows using either one or two carapaces each and decorative banjo-like musical instruments, each using a single carapace as the resonator.
Turtle shell is also traded to supply the traditional chinese medicine industry. These shells are usually by-products from the consumption of turtles, but there have been some reports of the specific collection of turtle plastron, after which the rest of the animal was discarded or perhaps used as food in crocodile farms. Turtle shell is used for the production of turtle jelly, a glue-like residue produced by long-term boiling of turtle shells and concentrated by evaporation. There are indications that this jelly is also manufactured outside East Asia in Indonesia and perhaps other source countries. This jelly is transported as a high-value, low-volume product, and it is impossible to check its composition. This creates problems for customs inspections, as well as consumer concerns about genuine content.
Modern chelonians are classified into two suborders, according to the method of retracting the head into the shell. The most primitive group are the side-necked turtles (Suborder Pleurodira), which have very long necks to assist in catching fish. In these chelonians, the neck bends sideways in order to fit the head into the shell. There are about 45 species, all of which are aquatic terrapins, and which are found in South America, Africa and Australia. The more recent suborder, Cryptodira, contains the majority of living species. In this group the head is drawn backwards into the shell, the neck forming an S-shaped vertical loop. Most modern species belong to this group, including the turtles, tortoises and most terrapins.
There is considerable cultural variation in response to tortoises, turtles and terrapins. In certain areas, tortoises are regarded with favour and may be kept as pets in the hope that their presence will discourage snakes from entering the house. Terrapins in particular are believed to play host to powerful djinns, or water spirits, especially those living in the vicinity of sacred springs. It is considered extremely bad luck to harm such a terrapin.
In Buddhist cultures, releasing a turtle or tortoise into a temple is considered an act of great charity, to be rewarded in ones next incarnation.
Turtles are caught and killed in their millions for food in Asian countries -- notably Laos, Cambodia, Bangladesh, Vietnam, Malaysia, and Indonesia, and also Pakistan, India and Nepal -- often to meet the insatiable demand and high prices offered by Chinese markets. The Chinese three-keeled box turtle can sell for as much as US$1,000 in China, where it is seen as a powerful cancer cure.
Asian river turtles are subject to a three pronged attack: the collection of adults, harvesting of eggs and destruction of habitat. This for example, has led to a reduction of Batagur baska in peninsular Malaysia by over 90% in the last century. In Thailand there were an estimated 2,600 Batagur baska and Kachuga trivittata nesting communally in the Ayeyarwady river delta in 1890. By 1899 this population was down to 820, while in 1982 the same area accounted for "only a few". Most recently, a United Nations Development Program found none.
In 1996, 3.5 million kg of turtles of many species were imported and consumed in Hong Kong alone. This approximates well over 3 million turtles in one year. In 1993 approximately 200,000 - 300,000 individual turtles and tortoises were exported from the Cau Mong market in Ho Chi Minh City.
In the USA, 21 of the 55 species are protected by law or under consideration for protection. But more than 7 million turtles are exported from the United States every year as food or pets.
The amount of turtle shell imported to Taiwan alone exceeds 100 metric tons per year, and the total trade may add up to several times this amount. Turtle shell represents about 5-20% of the weight of an average turtle; if the shell trade concerns plastron only, shell trade figures should be multiplied by a factor of 20 to estimate the total weight of animals affected.