Shark DNA forensics
Project Leader: Mahmood Shivji
Background
As the market for shark fins grows at an alarming rate, so the pressure builds on already depleted shark populations. As an example of these concerns, a piece of research carried out by project leader Mahmood Shivji and his team, analysed fin market trade data that suggested that the amount of sharks represented in the international fin trade is substantially greater (by between 300-500%) than shark catch figures reported to the U.N. Although both management and legal measures have been put in place in an attempt to control targeted shark fisheries, most end up running into trouble for two major reasons.
Firstly, it is often impossible to identify exploited shark species, especially in international trade arenas where they are often uncovered in the form of body parts. Secondly, even when a shark’s species can be identified from its DNA, the genetic structure of shark populations at a global level is so poorly understood that it’s virtually impossible to tell which population the sample came from, let alone where in the world it was caught. With only unidentified shark fins as evidence it becomes almost impossible to enforce existing legislation.
Firstly, it is often impossible to identify exploited shark species, especially in international trade arenas where they are often uncovered in the form of body parts. Secondly, even when a shark’s species can be identified from its DNA, the genetic structure of shark populations at a global level is so poorly understood that it’s virtually impossible to tell which population the sample came from, let alone where in the world it was caught. With only unidentified shark fins as evidence it becomes almost impossible to enforce existing legislation.
In the field
Mahmood Shivji
Mahmood Shivji and his colleagues at the Guy Harvey Research Institute, have already developed a streamlined forensic DNA tool that is able to identify 30 species of shark found in the fin trade; thus far, these techniques have already been used to assist the U.S. NOAA’s Office for Law Enforcement to identify shark body parts as part of 21 case investigations.
Results from a further genetic survey of market obtained shark parts, including the world’s largest market in Hong Kong, showed that fins from several IUCN (International Union for Conservation of Nature) listed, as well as at least two CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), as well as other nationally protected species (e.g., hammerheads, white sharks, basking sharks, dusky sharks, porbeagle sharks and grey nurse sharks) occurred in the trade. This strongly suggested that threatened, and in some cases illegal-to-fish species, are experiencing unsustainable exploitation in international fisheries.
Results from a further genetic survey of market obtained shark parts, including the world’s largest market in Hong Kong, showed that fins from several IUCN (International Union for Conservation of Nature) listed, as well as at least two CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), as well as other nationally protected species (e.g., hammerheads, white sharks, basking sharks, dusky sharks, porbeagle sharks and grey nurse sharks) occurred in the trade. This strongly suggested that threatened, and in some cases illegal-to-fish species, are experiencing unsustainable exploitation in international fisheries.
Aims & objectives
This SOSF supported research will continue its already groundbreaking work by determining the genetic population structure for shark species of conservation concern on a global-scale. It will then use this information to further develop DNA forensic tools to track both the species and population origin of internationally derived fins and other shark products. This work will then continue to aid law enforcement efforts in helping to detect landings and the trade of protected species and populations.
The overall aim of this project is to provide the global population genetic structure information that will permit, for the first time, substantially improved shark conservation, law enforcement, and management by allowing landings and trade to be monitored on a species and population-specific basis. The initial findings have already created a great deal of media interest. Regular dissemination of the ongoing results will also help achieve the Consortium’s goals of improved shark conservation and management, and increasing educational and public awareness.
Project Update: 2009
Specific objectives identified:
- Determine the detailed, worldwide population genetic structure of threatened and/or regionally protected shark species known to occur in the fin trade. Initial species targeted for study will be Sphyrna lewini, Sphyrna zygaena, Lamna nasus, Galeocerdo cuvier, Carcharhinus amblyrhynchos, Carcharhinus signatus, Carcharadon carcharias and Carcharias taurus.
- Use the population structure information from Objective 1 to determine the geographic origin of market derived, genetically identified (to species) fins.
- Based on the population structure information from Objective 1, develop streamlined, simple-to-use forensic tools that will simultaneously identify species and geographic origin of market derived shark fins.
- Disseminate our research findings and forensic tools to the management, conservation, and scientific communities and general public, as appropriate, under the SOSF-NSUOC SCC.
To read more about Mahmood and his colleagues' work check this issue of Innovations.