Conservation, Management, and Rehabilitation

It is interesting to note in Swettenham’s account that the Malays were already practicing conservation methods for the river terrapins in the nineteenth century. By protecting the beaches from poachers and leaving the third laying to hatch, they maintained moderate recruitment to offset the egg harvest. Similar conservation measures existed on the Amazon River in the nineteenth century to protect the heavily exploited giant South American river turtle, including the protection of females and leaving a third of the eggs laid on the beaches to hatch (Goeldi, 1906 in Parsons, 1962; see also a brief history of exploitation patterns of this species in chapter 5, this volume.). Unfortunately, conservation actions such as these have been the exception rather than the rule in human interactions with river turtles. As emphasized in earlier chapters, populations of most riverine turtle species have seriously declined from nineteenth century levels, but unlike the general declines reported for amphibians, most of the causes are obvious. The burgeoning commercial exploitation for food, traditional medicines, and pets, expanding populations of traditional and introduced predators, and extensive habitat destruction exemplified by such practices as sand mining, damming, channelizing, and pollution of flowing waterways have been key factors. We know far better how we reached this state of decline than how we can reverse the trend. Since the early beginnings of river turtle conservation chronicled by Swettenham and Goeldi, a variety of conservation techniques have been tried world-wide. As there are few proven methods, most actions have been based on what seemed logical or was simply cloned from the methods being used in sea turtle conservation programs. The latter may not have been the best approach for as Pritchard warned in a 1980 paper (Pritchard, 1980b) “sea turtle conservation remains without a theoretical framework, and almost all techniques that have been used remain unproven and riddled with paradox.” Conservation methodology is generally divisible into two divergent approaches, one emphasizing in-situ (on site) techniques and the other ex-situ (off site) techniques. The former aim at protecting animals and their habitat while minimizing intrusion into the life history of the target species.