During the summer of 2012, I spent six weeks working with the Marine Megafauna Foundation in Mozambique. Our goal was to collect non-invasive samples from manta rays to determine whether the sampling process was suitable for conducting DNA studies. While on SCUBA, we would carefully approach mantas who had come to reef cleaning stations (learn more about cleaning stations here). The first task was to take a photo of the manta’s belly – Dr. Marshall has developed a database to identify individual manta rays by the unique spot patterns which allows researchers to track mantas worldwide.
After a successful photo-op, we would approach the manta and gently remove a small amount of surface mucus with a very sophisticated and carefully designed research tool… a travel size toothbrush.
When we had collected the mucus and safely made it back to shore, we would apply the mucus to specially treated paper that preserved the sample and allowed for dry-storage. This was a great step in the sampling process because it allows for easy storage and transport even in the most remote and primitive field sites.
When the field sampling was over – the work was just beginning. Next it was up to a great team of molecular biologists to make sure that the DNA we had stored in our mucus samples was indeed from our mantas and that there was enough of it to be useful for analysis. In the end, we were indeed able to confirm that it was the right DNA and that the process preserved enough material to be potentially useful for future projects.
So, why should you care about this study?
Sharks and rays are threatened globally due to direct pressure from fishing as well as indirect threats such as entanglement and habitat loss. Developing a non-invasive sampling protocol allows for researchers to continue studying these wonderful animals without being concerned of negative impacts on the animals from the study protocol itself. Manta rays are not only important members within their own habitats but also are a major draw for tourism in many developing nations. Mozambique is considered a “hot spot” for diving with manta rays and I often met people who had traveled from around the world to come spend a few days in a tiny village with hopes of seeing a manta ray in the wild.
Would you like to read the article yourself? Download it here: https://peerj.com/articles/1188/
Dr. Marshall and the Manta Ray Team also have a wonderful tagging project that helps us learn about manta ray migration. Click here to see how a tag is applied!