Threats from wildlife trade: The importance of genetic data in safeguarding the endangered Four-eyed Turtle (Sacalia quadriocellata)

Abstract

Wildlife trade has been considered one of the largest threats to biodiversity in Southeast Asia. Many vertebrates, such as pangolins, elephants and turtles have been heavily hunted as a result of high demand from emerging markets in China and other countries in the region. In Vietnam, over-exploitation of turtles over several decades to supply the international trade has extirpated numerous populations and driven several species to the brink of extinction. To reverse this trend, conservation measures, such as re-introduction of confiscated or captive-bred animals to their native habitats, should be implemented to recover severely declined local populations. For species with a complex phylogeographic structure, however, it is crucial to understand geographic patterns of genetically-distinct populations to avoid releasing animals of unknown origin to wrong localities. In this study, we investigate the phylogeographic pattern of the Four-eyed Turtle (Sacalia quadriocellata), a widely traded species, which occurs in southern China, northern and central Laos and much of Vietnam, using samples with known localities and those collected from the local trade. Our range-wide phylogenetic and network study, based on the complete mitochondrial cytochrome b gene, recovered at least three major clades and seven subclades within the species range. Amongst these, two subclades, one from northern Annamites, Vietnam and the other from north-eastern Laos, are newly discovered. The fine scale phylogeographic analysis helped us to assign misidentified sequences from GenBank and those from confiscated animals with unknown origin to well-defined geographic populations. The results highlight the importance of incorporating samples collected from the local trade and the wild in genetic analyses to support both ex-situ and in-situ conservation programmes of highly-threatened species in accordance with the IUCN’s One Plan Approach.

Using terrestrial leeches to assess the genetic diversity of an elusive species: The Annamite striped rabbit Nesolagus timminsi

“…With this information, it is possible for enforcement agencies to identify the origin of the illegally traded wildlife, which can in turn help with the reconstruction of wildlife trade networks and the disruption of supply chains and hotspots of illegal activities. Phylogeographic information can also inform decisions regarding where to release confiscated animals; such information is often critical to avoid genetic pollution by mixing individuals from genetically distinct populations (Fitzpatrick & Shaffer, 2007; Rhymer & Simberloff, 1996) and releasing locally adapted animals to incorrect localities with entirely different environments (Le et al., 2020). In all of these cases, eDNA and iDNA can help to overcome the lack of reference sequences that often hinders obtaining a better understanding of where illegally traded specimens have originated from.…”

“…Genetic information obtained from eDNA or iDNA sources may also become of interest for forensic sciences, as phylogeographic data are often missing from traded species confiscated from the illegal wildlife trade. Identifying the geographic origin of illegally traded wildlife specimens is important for law enforcement and species conservation (Alacs et al, 2010;Blair et al, 2017;Kunde et al, 2020;Le et al, 2020;Melton et al, 2012;Wasser et al, 2008;Zhang et al, 2015) but requires an accurate genetic reference database that includes data from across the species' range. With this information, it is possible for enforcement agencies to identify the origin of the illegally traded wildlife, which can in turn help with the reconstruction of wildlife trade networks and the disruption of supply chains and hotspots of illegal activities.…”

“…Relevant genetic information often includes the current genetic profile of existing individuals within a population, as well as phylogeographic data, which describes the geographic distribution of a species and its populations in an evolutionary and phylogenetic context (Avise, 2000, 2009; Patel et al., 2017). For highly threatened species that rely on ex situ conservation actions, understanding a species’ intraspecific genetic variation is critical to inform conservation management, for example, by allowing conservationists to maintain appropriate levels of genetic variability within conservation breeding populations, or selecting appropriate individuals for translocations (Hassanin et al., 2012; Ivy et al., 2009; Le et al., 2020). Obtaining such genetic data often poses a challenge, particularly if the species of interest is rare, elusive, or occurs across a broad geographic area.…”

Creating genetic reference datasets: Indirect sampling of target species using terrestrial leeches as sample “collectors”

“…Furthermore, genetic information from populations across species' geographic range can assist forensic scientists in tracing the origin of confiscated animals and animal products in the wildlife trade (Blair et al, 2017;Eaton et al, 2010;Le et al, 2020;Wasser et al, 2008;Zhang et al, 2015). The lack of such genetic information often hampers law enforcement effectiveness (and potential convictions) as the origin of the traded animals or animal products cannot be determined.…”

“…Understanding the genetic diversity of species and populations is key to taxonomic assignments, which in turn are necessary for modern adaptive species management (Isaac et al, 2004; Mace, 2004; Wilting et al, 2015) and biodiversity assessments following the UN Sustainable Development Goals (https://sdgs.un.org/goals). Furthermore, genetic information from populations across species' geographic range can assist forensic scientists in tracing the origin of confiscated animals and animal products in the wildlife trade (Blair et al, 2017; Eaton et al, 2010; Le et al, 2020; Wasser et al, 2008; Zhang et al, 2015). The lack of such genetic information often hampers law enforcement effectiveness (and potential convictions) as the origin of the traded animals or animal products cannot be determined.…”