The magic of manta rays

Floating elegantly through the open blue ocean, slowly undulating with the passing water ripples like a flag billowing in a breeze, the seamless form of a manta ray is an enrapturing sight. Named after the Spanish for 'cloak', these majestic manta rays fulfil their namesake with immense poise and fluidity, gliding like dark kites throughout the water column in an enchanting dance-like pattern of feeding and breaching.

Manta rays: unique fish

Manta rays have long captivated humans with their graceful movement, gentle temperament and air of peace and serenity, becoming emblems of spiritual harmony, balance and intuition globally. Distantly related to sharks under the elasmobranch subclass of cartilagenous fish, there are two sub-species of manta ray; reef mantas (Mobula alfredi) which inhabit shallow coastal waters across coral reef areas, bays and atolls, and giant mantas (Mobula birostris), which are predominantly pelagic, found in the open ocean.

Though commonly traversing the tropical and subtropical seas as solitary individuals, manta rays often form large feeding aggregations in food-rich areas, sometimes up to 20 animals strong. Both species of manta ray are filter feeders, feeding predominantly on plankton, krill and shrimp, which often proliferate in dense 'blooms', attracting large groups of mantas as well as many other marine megafauna, spectacles of high interest to tourists and wildlife watchers. Congregations also occur at cleaning stations within coral reefs, where specific species of fish - namely cleaner wrasse and gobies - feed on the dead skin and parasites on the surface of the manta rays, cultivating a mutualistic relationship where both parties benefit from the interaction.

Manta rays also have an unusually large brain size compared to their body mass, and display brilliant and social behaviour. As migratory species, manta rays travel long distances across the oceans, driven by changing prey densities, current patterns and seasons. They also travel to specific locations for breeding, and distributions can also be impacted by increasing and decreasing water temperatures. During these long journeys, rather than 'sleeping', mantas will reduce their speed and energy use for short periods of rest, essentially cruising effortlessly and allowing time for recuperation and recovery.

The social structure of manta ray populations is still being studied, however it is known that highly complex communication and social interaction is displayed by these animals, such as engaging in intricate courtship behaviors, mating trains, and curiosity surrounding divers and human interaction.

Manta ray hot-spots

Feeding aggregations frequently reoccur in the same locations, leading to manta ray 'hot-spots' which are effective tourist magnets, especially for divers and snorkelers who want to get up close with these magnificent, but gentle, animals. Famous hot spots include Socorro Island (Mexico), Yap (Micronesia), Raja Ampat (Indonesia) and Hanifaru (Maldives). Due to crystal clear waters and world-class diving conditions, the Maldives archipelago is one of the top destinations for viewing manta rays in their natural habitat, forming a large tourism and conservation body in the region solely focused on observing and protecting these rays.

The turquoise blue waters of the Baa and Raa atolls in the Maldives are excellent spots to see mantas at their best, feeding, playing and breaching. The BAA atoll falls within a UNESCO Biosphere Reserve, providing close to pristine conditions and a rich environment where the mantas thrive and flourish. The protections provided by the reserve regulations also safeguard the Maldivian manta populations from the growing list of threats putting pressure on the species, granting refuge to maintain this pocket of rays for the future.

Threats and conservation efforts

Despite the global love and appreciation of manta rays, these elasmobranchs face a swathe of threats which is continually intensifying. Climate change impacts, such as warming sea temperatures, ocean acidification, and changing prey populations and timings of plankton blooms, make life challenging for manta rays to secure adequate nutrition and maintain normal body functions in a constantly changing environment.

On top of this, human activities such as overfishing, pollution and coastal development further threaten manta ray populations; direct targeting of the species by fishers is a huge issue, compounded by accidental fatalities through by-catch. Ocean pollution, such as chemical waste, plastic, and fishing gear, is a direct hazard to mantas, and collisions with boat traffic cause additional reductions in population. Tourism can also heavily impact manta rays, with dense congregations of tour boats and unregulated snorkelers and divers causing stress to the animals, impacting natural behaviour and disturbing normal communication patterns, feeding and mating.

The giant manta ray has been classified as endangered, whilst the reef manta ray is deemed vulnerable, both due to the pressures above felt throughout the species' range. Both species have slow reproductive cycles and hence are highly vulnerable to population declines, putting manta rays in a precarious position. To mediate this, multiple conservation initiatives have been implemented across the tropics to tackle threats to manta rays and preserve the remaining populations. Projects involving scientists, volunteers and tourists work together with governments and NGOS to collect data and monitor manta populations, recording abundance, health, population dynamics and behaviour to gain a deeper understanding this unique fish and its life history, and to identify patterns which may help effective conservation measures, such as new policies and protected zones, to be put in place where necessary. Such projects also help educate visitors and locals about manta rays, facilitating the important connection between people and wildlife, and garnering growing support and respect for these spectacular creatures.

The future of manta rays

With increased monitoring, research, and education, the remaining populations of manta rays can be maintained; as with all cases of vulnerable and endangered species, a holistic approach is required - protection of habitat, food sources, and the individual animals themselves is needed to ensure successful recovery of populations. Due to the vast range and migratory nature of manta rays, this demands that protection is approached through cooperative collaboration between governments and nations, and agreements adhered to without breaches or exceptions.

At a finer scale, isolated projects and conservation efforts are also important, and the Maldives is leading the way by setting a stellar example for manta ray conservation. Protected areas such as the waters of Hanifaru Bay limit human interference, while several long-term research projects are successfully monitoring populations and sharing crucial information and new findings to help guide further policy and protection.

Additionally, tourists' involvement in citizen science programmes is spreading manta ray knowledge and appreciation throughout global communities. Diving and live-aboard opportunities offer valuable experiences for visitors to contribute to science and learn about manta rays first-hand. To get involved in hands-on conservation of manta rays whilst exploring the enchanting island chain of the Maldives, check out our Manta Ray Conservation Expedition.