The effectiveness of conventional and community-based management approaches to the conservation of Amazon River turtles at Rio Trombetas Biological Reserve, Para, Brazil

Abstract

Amazon river turtles are under significant threat from overharvesting. Since the late 1970’s the Bra-zilian Government has established a number of Biological Reserves for protection of their nesting sites. The conventional approach of managing river turtles within these reserves, also referred to as the “fences-and-fines” approach, relies on the efforts of a few Government rangers patrolling the main nesting sandbanks with minimal involvement from the local community. This method has been used at the Rio Trombetas Biological Reserve (ReBio-Trombetas), in Pará State, Brazil, since the early 1980’s, to protect the Giant South American River Turtle (Podocnemsis expansa). More recently, a “community-based management” approach to conservation has been trialled at Lake Erepecu in the ReBio-Trombetas to protect two other species of riverine turtles (Podocnemis unifilis and P. sextu-berculata). This approach involves active participation of the local community in the protection of turtle nesting beaches. Our study tested the effectiveness of these two approaches to Amazon river turtle conservation, based on the number of hatchlings produced each year. Our results suggest that a detailed understanding of the life-history traits of species is fundamental to determining effective management measures for conservation. The effectiveness of the two management approaches (“fences-and-fines” or “community-based”) under the Trombetas scenario was highly related to the turtle nesting behaviour. Podocnemis unifilis and P. sextuberculata conservation is more effective under a community engagement program. In contrast, our model indicates “fences-and-fines” as the most appropriate approach for P. expansa, which is socially gregarious during the nesting season. However, the number of P. expansa hatchlings at the Reserve has declined by 94% from 1981 to 2016. The early success of the management approach trialled at Lake Erepecu suggests that conser-vation programs which engage the community, and recognise the importance of protecting all life stages, have a greater chance of success.

Date of Award	Aug 2019
Original language	English
Awarding Institution	Charles Darwin University (CDU)
Supervisor	Carla C. Eisemberg (Supervisor) & Penny Wurm (Supervisor)