Also Known as Mantas or Devil Rays
In 2020, researchers Marta Palacios, Melissa Cronin, and Nerea Lezama-Ochoa founded the Mobula Conservation Project with support from the international organization Manta Trust. Since then, they have been tirelessly working to protect these fascinating marine creatures. The team of marine biologists met on El Pardito Island in the Gulf of California, a region home to five species of mobulas. The smallest, Mobula munkiana, has a wingspan of just 1.1 meters, while the largest, Mobula birostris, reaches an impressive seven meters with its flippers extended.
Whether implanting acoustic tags from boats, piloting drones, or investigating the black market, the scientists of Mobula Conservation are dedicated to protecting these species. “We do science for action; everything has a conservation objective,” says Palacios. Their research focuses on habitat use, spatial ecology, oceanographic preferences, and the population genetics of manta and devil rays.
Mobulas belong to the Mobulidae family, making them relatives of manta rays. They also share a broader taxonomic group with sharks and chimaeras, distinguished by their cartilage-based skeletal structure.
In the eastern Pacific Ocean, mobulas gracefully alternate between the silent undulation of their fins underwater and spectacular leaps above the surface. However, this mesmerizing scene is under threat due to targeted fishing, bycatch, the black-market demand for their meat, and climate change. Standing between these creatures and extinction, Mobula Conservation scientists are determined to safeguard them, working hand in hand with artisanal and industrial fishers to change the course of their fate.
More than a third of all mobula species are at risk of extinction. Of the nine known species, seven are endangered, and two are classified as vulnerable, according to the International Union for Conservation of Nature (IUCN) Red List.
In the Gulf of California, a boat once served as a research center for tagging mobulas. Here, Palacios implanted small acoustic devices that transformed these animals into sources of valuable data. Fishermen, hired for the project, carefully captured and released the rays back into the water. This method, known as passive acoustic telemetry, may seem invasive, but it is conducted with extreme care. Once released, the tagged mobulas resume their natural movements.
Every time a tagged mobula passes near an underwater receiver, its presence is recorded, along with the date and duration of its visit. Through this data, Palacios identified a previously unknown breeding ground for M. munkiana in a bay in the Gulf of California. To piece together the life history of these creatures, she collects testimonies from fishermen and uses drones to observe their massive aggregations.
At sea, scientists engage in a range of activities, from performing minor surgical procedures on small boats to implant acoustic transmitters, flying drones over mobula schools, diving to film them underwater, sailing at night to assess the impact of bycatch, and uncovering illegal trade networks. Lezama has spent years modeling critical mobula habitats in the Pacific Ocean, while Cronin collaborates with geneticists at the University of California, Santa Cruz, to analyze population dynamics.
Although the total number of mobulas in the ocean remains unknown, fishery landings suggest significant and rapid population declines, particularly in regions like Costa Rica and Mozambique. For instance, the tuna industry unintentionally captures nearly 13,000 mobulas each year. To address this issue, Cronin and Lezama study industrial fishing practices in Ecuador, while Palacios focuses on artisanal fisheries in the Gulf of California. Their goal is to uncover the life histories of these animals and engage fishermen in their conservation efforts.
For 11 years, Palacios has called the Baja California Sur desert home, dedicating her career to the study of mobulas. In 2014, during a five-day research expedition in the Gulf of California, she encountered Mobula munkiana for the first time. “They were everywhere, jumping nonstop, and no one knew what they were doing or where they were going,” she recalls. This lack of understanding fueled her scientific curiosity.
M. munkiana forms some of the largest known aggregations of marine animals, with thousands of individuals covering vast distances. They are found throughout the eastern Pacific, from Peru to Mexico, where they are nicknamed “tortilla” or “flame tortilla” due to the sound they make when hitting the water after a jump, like making tortillas with your hands.
Mobulas are not the only cartilaginous fish that leap from the water. Many species do so to rid themselves of parasites, clean their gills, or as part of courtship displays. However, unlike sharks and manta rays, which typically jump alone, M. munkiana leaps in large groups. This behavior occurs year-round, involving newborns, adults, males, and females alike. “Jumping likely serves multiple functions within their communication, but we don’t yet fully understand what they’re conveying,” says Palacios.
In coastal regions, large mobula gatherings put them at risk of becoming entangled in artisanal tuna fisheries that employ gillnets and purse seines. To make matters worse, their slow reproductive cycle works against them. Depending on the species, mobulas take five to ten years to reach sexual maturity. They endure long gestation periods—lasting over 12 months—and typically give birth to just one pup at a time. With intervals of two to seven years between pregnancies, their population growth rate is exceptionally slow.
A recent scientific expedition led to the discovery of five previously unknown mobula species. The researchers hope their findings will inspire governments to actin protecting these remarkable creatures before industrial exploitation destroys their habitats.
Visit the Mobula Conservation Project website for more information.