- To develop tools for traceability of mobulid parts to address the gill plate trade.
- To understand the extent and nature of local adaptation within manta populations around the world, and investigate the evolution and maintenance of the black morph mantas.
- To investigate the factors driving the recent divergence of manta rays into two separate species.
Project Start Date:
The main focus of the Manta Trust Genetics Project is to develop tools for the conservation and management of manta and mobula (devil) rays worldwide. This is being achieved by making use of advances in Next Generation Sequencing techniques that allow a close look at sections of DNA across entire genomes. We work to develop a Global manta and mobula (mobulid) Genetic ID kit which can be used to identify a ray or any of its parts to species and regional level for monitoring and enforcement of conservation regulations. Genetic data can also be used to investigate patterns of adaptation, and diversification of mobulids, in order to further inform conservation policy.
Why this is important:
Manta and mobula rays are under threat globally from both target and bycatch fisheries, which supply the trade for their gill plates which are used in some traditional medicines; despite there being no evidence for their effectiveness. Unfortunately, populations of these rays cannot easily recover from fishing, as they have low reproductive rates. Despite global legislation being passed in 2013, regulating the trade of manta gill plates, the sad reality is that it still goes on, and worse, it is very difficult to identify plates to species level, or know where they came from, and therefore where conservation work is most sorely needed.
Another threat is climate change, which is predicted to affect core ocean processes regulating the levels of plankton, on which mobulids feed. As these dynamics change, the animals that rely on them will have to adapt – or face extinction. There is a growing body of research which shows that populations that are genetically diverse have greater ability to adapt to environmental change and are therefore resilient to extinction. Genetic data allows us to investigate how individual populations may be adapted to their local conditions, and therefore understand how they may respond to changes in the environment.
Manta Trust scientists are working to develop genetic tools to address problems of exploitation for gill plates. As a result of the trade, manta rays were recently listed on the Convention on the International trade in Endangered Species (CITES) which regulates the trade in endangered species and their parts. However, morphological similarities and taxonomic uncertainties make identification of mobulid rays and their traded parts challenging, and partly due to these difficulties, CITES regulation for mobula rays is not currently in place. This project sets out to provide a genetic means of identification to aid in the enforcement of CITES regulations for manta protection, and provide support for potential protection for mobula rays.
Wildlife forensics is a field which effectively uses genetic techniques for the traceability and identification of animal parts. Making use of samples from all over the world, representing contributions both from other Manta Trust Projects, but also other researchers, the project uses advances in Next-Generation Sequencing techniques to scan the entire genome of mobulid species, to identify those genetic regions that are consistently different between species and can therefore be used to assign a part to a species, to aid in the enforcement of current and future CITES regulations. Likewise, these techniques can also be used to discover areas of the genome that differ between populations, and therefore identify a sample to regional level. This information can be used to allow enforcement by the appropriate country, but also to highlight those regions primarily supplying the trade in gill plates, and therefore where outreach, education and enforcement is most required.
By studying differences in manta populations, we can start asking questions about how they are adapted, and how they diversify. We now know, for example, that two species of manta ray exist; reef and oceanic mantas, and as the names suggest, each prefers a slightly different habitat. By studying the genomic regions that allow each species to fit into its own niche, and how these differ in different locations, we can begin to understand how individual populations are interacting with their environment, and therefore inform conservation policy. By identifying those populations that possess unique adaptations, we can make a case for the increased protection of such a population. For example, this project is investigating the evolution and maintenance of two distinct colour morphs; chevron and black mantas, in order to gain a broader understanding of adaptation within the group. Some populations, especially in the Pacific Ocean, have a much larger prevalence of black morph mantas than those in the Indian Ocean. We are working to obtain samples of both colour morphs in order to investigate the reasons behind such differences, and ask whether there are particular advantages to these characteristics in different places.
The specific objectives of this project are to:
- Enable species identification and traceability of mobulid products to address stock monitoring and enforcement of regulations regarding gill plate trade.
- Examine processes leading to differentiation at the genomic and trait level between the recently diverged manta species.
- Describe population structure and demographic history of both species of manta and both colour morphs throughout their range through a ‘seascape genetics’ approach in order to understand resilience to environmental change.
Partners & Sponsors:
The Manta Trust’s Genetics Project is based primarily within the Molecular Ecology and Fisheries Genetics Laboratory at Bangor University, and has supervisory and technical support from the Royal Zoological Society of Scotland and TRACE Wildlife Forensics Network. This important work is made possible by generous support from the Save Our Seas Foundation, the Royal Zoological Society of Scotland and the Natural Environment Research Council through the ENVISION DTP. This project also maintains collaborations with manta and mobula researchers all over the world.