The giant manta ray is a fearsome sight. They measure nearly 25 feet across, weigh up to 4,000 pounds, and move with surprising speed. Yet Andrea Marshall feels only awe and admiration when she sees them soar by just inches away.
The self-proclaimed "Manta Queen" is a scientist and photographer in Mozambique who has spent 15 years studying these magnificent creatures. Her obsession started in high school when she snapped a photo of a manta ray during a dive in Costa Rica. "It flew at me like an underwater bird," she says. "I was completely gobsmacked." Marshall eventually earned a doctoral degree from the University of Queensland in 2009 and discovered that manta rays include two species, including the previously unknown giant manta, manta birostris. That same year, she founded the Marine Megafauna Foundation.
Mantas inhabit tropical and subtropical waters. Although the smaller species, Manta alfredi, tend to stay relatively close to shore, their larger cousins roam the open ocean. They live as long as 50 years, eat plankton, and, like sharks, must keep in constant motion. These intelligent creatures have the largest brain relative to body size of any fish, and exhibit the greatest poise and grace. “They know where every single fin is at all times, and they will miss you by millimeters as they come toward you,” Marshall says.
As with so many pelagic animals, giant mantas remain something of a mystery. Scientists can't say how many exist, how fast they swim, or where they give birth. To solve some of these mysteries, Marshall launched Manta Matcher in 2011. She calls the photographic database “Facebook for mantas,” and encourages divers to upload geotagged photos showing a manta's distinctive spots. An algorithm identifies each animal and matches it to individual albums. The catalog provides an inexpensive way of tracking mantas over time. “It helps us understand things like how long mantas can live, how far they travel during their lifetimes or conversely how resident they are and how fast they grow,” Marshall says.
Marshall contributes to the database regularly, making dozens of dives each month in Mozambique and around the world. “Everything we know about these animals comes from our observation of them,” Marshall says. “Photography is the way that we capture information on both the individual level and about the populations as a whole.” She always goes for an identification picture of the belly first, then takes a glamor shot or selfie with the animal. It’s not easy, because mantas are quick.
Mantas face a mounting threat from industrial fishing and demand for their gill plates, which are used in traditional Chinese medicine. Marshall's database of images is a big step toward saving these gentle giants.
