Manta Catalog Azores

The Azores islands

One of the few places on earth where sicklefin devil rays (Mobula tarapacana) gather in large groups.

Located in the middle of the Atlantic Ocean, the Azores is an archipelago consisting of nine volcanic islands, the most isolated in the North-east Atlantic. Being the only landmass between two continents and sitting on top of the middle Atlantic Ridge, together with the strong influence of the Gulf stream, makes for its unique environment, a true oasis of biodiversity.

From the islands’ shores to the depths of the deep sea, the archipelago encompasses important and diverse ecosystems, from coastal reefs to seamounts, hydrothermal vents, and deep water coral gardens.

Project Overview

The Sicklefin devil ray is the only devil ray species that bears unique ventral markings, similarly to manta rays.

In fact, this feature led to the genesis of this project and the establishment of the first photo-ID database for the sicklefin devil ray in the world and, subsequently, for the oceanic manta in the Atlantic. Over time, these databases can reveal information on the make-up of populations, migration patterns and movements around the Azores, while uncovering possible connectivity with other regions in the Atlantic and providing clues on the importance of this region for the different species. This information is crucial in order to effectively manage and conserve these rays.

The presence of predictable aggregations at seamounts in the archipelago is therefore highly significant, providing a unique opportunity to study these animals. Most of MCA’s work has been conducted in collaboration with local dive operators and their guests, who support the project as ‘Citizen Scientists’. Guests contribute any ID photos captured during their dives, and dive operators report any sightings of mobulas that occurred throughout the season. More recently, local recreational fishermen have also undertaken to report encounters they have with these animals.

Along with photo-ID, the project has also gathered data through remote video stations at the main aggregation sites. Collaborations on the use of new methodologies and the collection of genetic samples have recently been established in other regions. Genetics and genomics techniques have been used to study the population structure of sicklefin devil rays and the connectivity of populations between the Azores and different regions around the globe.

The ecological role of these very specific aggregation sites needs to be comprehended and assessments need to be carried out on how potential negative impacts at these locations can be avoided through regulation.

The project hopes to boost the amount of ID data it collects from visiting divers in the future, and to raise awareness among the wider local community regarding conservation and the economic importance of the mobula rays that visit the region.

Mantas and devil rays in the Azores

Between June and October each year, one species of manta (Mobula birostris) and two species of devil rays (Mobula tarapacana and Mobula mobular) can be seen in the waters around these islands.

The most commonly sighted is the large and charismatic Sicklefin devil ray (M. tarapacana). This species is well known for its golden colour and is one of the largest species of devil ray, reaching wingspans of just under four meters.

Whilst Sicklefin devil rays can be seen across the archipelago during the summer months, they are most consistently seen aggregating in large numbers at the seamounts of Ambrósio near Santa Maria, and Princesa Alice near Faial and Pico.The aggregations of these animals near the seamounts provide a unique opportunity to study them. All the rays that visit are mature adults, and many females are heavily pregnant. However, the exact reason behind their visits remains a mystery. What we do know, is that these rays are not shy about interacting with divers. Their large aggregations, surprising size, and obvious curiosity makes for an incredible encounter and, therefore, many divers from all over the world visit the Azores specifically to see them.