As the largest ray species in the ocean, manta rays are iconic giants loved by divers worldwide and, as one of the most evolved and highly specialised forms of sharks and rays, they have a lot to offer scientists too.
Growing up to eight metres across, manta rays could easily be misinterpreted as intimidating animals, but their gentle, curious nature towards divers make encounters with them a welcomed underwater experience.
Sadly, many manta ray populations across the globe are in decline in response to human-induced threats such as pollution, boat strikes and habitat destruction. Populations, which are often small, are also easily overfished, a problem which is exacerbated by the fact that manta rays have conservative reproductive rates, on average giving birth to only one offspring every two to three years. As a result, manta rays are ill equipped to face a predator as efficient as humankind.
The Marine Megafauna Association (MMA) was formed to research, protect and conserve large marine animals found along Mozambique’s coastline.
The MMA’s flagship manta ray programme is one of the most comprehensive long-term studies on the planet. The research team examines issues directly relating to East African manta ray population management, works to support the sustainable development of the Mozambican tourism industry and promotes education initiatives in local schools and local fishing communities.
Recently, with the assistance of Ecocean USA, MMA’s team launched the first online global database for manta rays.
The Manta Matcher system uses the unique spot patterns on manta rays to identify and track individuals over time. This simple, non-invasive technique enables scientists to gain a better understanding of the global distribution of manta rays, examine long-term movements and track the longevity of known individuals over time. And this is where you as divers and tourists can lend a hand.
Public participation in this programme is easy and fun and represents a new wave of citizen science taking the world by storm. More and more scientists are welcoming the public’s involvement in global data collection efforts to accelerate what we know about threatened species and unite much needed global conservation efforts. By working together with scientists, the public will be able to share in the excitement as the first global effort to cross-match manta rays from different populations gets underway.
To get involved, go to www.mantamatcher.org to upload your photographs and directly contribute to the conservation of these gentle giants.
Manta ray facts
Despite their size, manta rays feed on some of the smallest organisms in the ocean, zooplankton. To satisfy their huge appetites, mantas eat up to 15 per cent of their body weight a week and spend their time roaming the ocean searching for their next meal.
They’re one of the few entirely pelagic ray species, meaning they’re in constant motion. These enigmatic rays also undertake some of the longest migrations and deepest dives of any fish in the ocean.
Blog by Andrea Marshall
Photo by Dylan Kotze