Solving Baja California’s manta ray mystery
Why did the giant manta rays (Mobula birostris) of La Reina suddenly vanish from the Gulf of California after 2003? Just as important – and puzzling – is why have they suddenly returned?
Once a popular aggregation site for oceanic manta rays in Mexico’s Gulf of California, La Reina has only sporadically seen a few individuals in the last 16 years. From 1999 to 2003, researchers identified 52 individuals of oceanic manta rays at La Reina, an islet just north of Cerralvo Island and a former cleaning station for this species of mobulid.
In 2016 researchers only identified three individuals. Theories for this include Intensive fishing practices combined with environmental factors and possibly unknown manta ray aggregation patterns.
Now the rays are back and seem to be sticking around. The mystery has intrigued WWF-Mexico, which has supported tagging studies of the region’s elasmobranchs. WWF and its partners began tagging operations in summer 2018, and have so far identified 15 juveniles, indicating that La Reina might be a nursery ground for this majestic species. Ultimately, the marine detectives of WWF-Mexico would like to learn when, where and why these animals travel and how these movements relate to the ocean environment. Keeping track of their movements might also help identify critical habitats worthy of spatial protection.
Equally beneficial, WWF-Mexico is seeing unparalleled collaboration with conservation partners, government and local scuba centers to protect the rays. These collaborations are not only helping WWF’s regional efforts, but also in developing best interaction practices for tourism operations.
The study is led by WWF-Mexico’s Georgina Saad, coordinator of the Ocean Practice species-at-risk program, with the help of specialist Esbaide Eliosa. Also assisting are partners including: Dr. Dení Ramírez, an expert on whale sharks and tagging studies, Erick Higuera, a manta ray researcher and underwater photographer, and Pelagios Kakunjá, a non-profit focused on elasmobranch research.
About the contributor
Yago Doson graduated in Biological Sciences at the University of Barcelona before completing his graduate studies in Fisheries Science from the University of British Columbia. He now leads the Sustainable Fisheries program at WWF-Mexico, where he focuses on using sound science to solve environmental and social issues, aiming to improve the overall sustainability of Mexican fisheries.