September 10, 2009 | 3
The illegal trade of bushmeat—meat and products made from wildlife—has grown dramatically in the past several years, thanks to high demand, enormous profits, a lack of law enforcement and minimal sentencing for criminals caught trafficking in bushmeat. The worldwide market for these illegal products reached an estimated $5 billion to $8 billion in 2008.
One of the major challenges in combating the bushmeat trade is identifying the source species for the meat and products. Once an animal has been carved up, meat looks like meat and leather looks like leather. How is anyone to know if it came from a species that is protected under national or international law?
A technique called DNA bar coding could be the answer. According to a paper published in the September 1 online edition of the journal Conservation Genetics, DNA bar codes can be used to quickly and clearly distinguish the source species of meat or leather goods for many rare and threatened species.
How would it be employed? Rather than work up a complete genetic profile of organic matter, the authors used DNA bar coding to look at a short region of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene. The DNA would then be identified in a lab at a low cost, since only the COX1 gene would need to be processed.
The researchers didn’t actually examine any endangered species, but they did sequence the bar code region of 25 commonly traded mammals and reptiles, many of which are embargoed from international trade by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).
"The species in our study are among the most commercially harvested species in South America and Africa," lead author Mitchell Eaton said in a prepared statement. "They are often partially prepared by the time they get to urban markets, which can make the species identification impossible." Eaton led the research as part of his doctoral research at the University of Colorado at Boulder.
The species examined came from South America and Africa, and included duikers, spiral-horned antelope, red river hogs, old world monkeys, alligators and crocodiles. The DNA sequences generated from this study will be added to the Barcode of Life Data Systems, an online, open-access database of bar codes.
Even though many of the samples they tested had degraded through the leather-making process or due to age, the researchers found they were still able to extract the COX1 sequence in most cases. In their paper, the authors conclude that with minimal effort and simple refinements to existing DNA extraction and polymerase chain reaction (PCR) protocols, "accurate bar code sequence data can be obtained from most wildlife products encountered in bushmeat monitoring programs and wildlife investigations."
"There is consensus on using the same fragment of DNA, COX1, to construct a library of life," said co-author George Amato, director of the Sackler Institute for Comparative Genomics at the American Museum of Natural History, in a prepared statement. "This is an example of where new genetic technology can be transformative to society, by using bar codes to catalog the diversity of ecosystems, to monitor invasive species, to search for pathogens in the food supply, and to observe wildlife trafficking for the pet trade and other commercial markets."
This isn’t the first time that DNA has been used to help identify wildlife products seized from illegal traders. Last year, Samuel Wasser of the Center for Conservation Biology introduced a genetic method to trace the origin of poached ivory. Earlier this year, research published in the Proceedings of the National Academy of Sciences recommended a set of standards for the DNA bar coding of plants.
Image: leather products on display in a craft market in Brazzaville, Congo. (Credit: Mitchell Eaton)