Marine Life & Conservation Blogs
Creature Feature: Manta Rays
In this series, the Shark Trust will be sharing amazing facts about different species of sharks and what you can do to help protect them.
This month they’re showcasing the largest rays in the world. Made up of 2 different species, these captivating giants are highly intelligent. And, come in a range of unusual colours!
The word ‘manta’ is Spanish for blanket or cloak, which perfectly describes the body-shape of a manta ray. These enormous, flat, diamond-shaped animals, have wingspans stretching up to 7m wide and can weigh up to 1,350kg.
Mantas also have 2 horns at the front of their head, giving them the nickname ‘devil fish’. But there’s nothing devilish about these gentle giants. Or their close cousins the devil rays, who often get confused for mantas. Both, use their ‘horns’ (or cephalic fins) during feeding to scoop up tiny plants and animals in the water. Similar to how we use a spoon to eat soup. Their cephalic fins may also play a role in sensing their environment and during social interactions.
Just like the Basking and Whale Shark, manta rays are filter feeders. Swimming with their mouths wide open, they suck in huge volumes of water – rich in zooplankton. Their tiny prey is then filtered through gill plates that line their mouth. Sadly, these gill plates are highly sought after in the Chinese medicinal trade, which has led to mantas being heavily over-fished.
As any diver can attest, seeing a manta in the wild is a pure delight. Their elegance and grace in the water is unrivaled. Particularly at feeding time. Mantas need to keep moving to breathe, so individuals will perform multiple somersaults to stay in a single spot where there’s lots of food. Like a perfectly orchestrated dance, mantas will also follow each other in a circle to chain-feed. Their movements expertly creating a vortex that traps their prey inside.
Manta Rays live in tropical, subtropical, and temperate waters around the world. They tend to live on their own or in small groups. But will often gather in large groups to feed. Hotspots for this feeding behaviour include the Bahamas, Fiji, Indonesia, Thailand, Spain and the Maldives. And aggregations are known as a squadron of manta ray.
In 2008, scientists discovered that the Manta Ray, which was once thought of as a single species, was in fact two different species. The Giant Oceanic Manta Ray (Mobula birostris) and the much smaller Reef Manta Ray (Mobula alfredi). Both species were formerly classified under the separate genus Manta. But following genetic testing in 2017, scientists discovered they were more closely related to devil rays (genus Mobula) than previously thought and reclassified them as such.
The Giant Manta is widespread, spending most of their time far from land in open ocean. While the Reef Manta tends to prefer the warmer coastal waters of the Indo-Pacific. Fully grown, the wingspan of a Giant Manta can reach up to 7m (typically 4.5m). While the largest wingspan for a Reef Manta is 5m (typically 3-3.5m). Both are dark in colour on top with a pattern of white lines. On the Giant Manta the white lines form a T shape, while on the Reef Manta they form a Y shape.
We can also identify each individual manta by their unique markings. Found on the underside of their body (between the gills and on their bellies), these act just like a human fingerprint. Enabling scientists to use photo-ID to discover more about them.
Manta Rays regularly visit cleaning stations, like many other marine animals, often returning to the same spot. Here smaller animals groom them, removing pesky parasites and dead skin. These spa trips to the coral reef provide researchers with the perfect opportunity to photograph and study them in the wild.
In Raja Ampat, researchers have discovered an unusual group of Reef Mantas, affectionately known as the ninja warriors. This area has the highest percentage of melanistic (black) Reef Mantas in the world. Usually melanistic mantas comprise around 10% of a population, but here they represent 40%. This genetic trait is inherited and doesn’t appear to affect their survival rate.
If you visit the Great Barrier Reef, you may witness an even more astounding sight…
A 3m male Reef Manta named ‘Inspector Clouseau’, who also happens to be bright PINK! Big thanks to Kristian Laine Photography for providing the incredible photo above.
The Inspector is the only known pink manta in the world. His rosy hue is believed to be the result of a condition called erythrism – a genetic mutation in melanin production. Again, this doesn’t seem to impact his survival. Indeed, he’s been spotted a handful of times since his first debut in 2015, so is doing well.
Highly intelligent, these majestic animals have the largest brain to body weight ratio of any fish. Studies suggest they have high cognitive function – similar to dolphins, primates and elephants – and excellent long-term memory.
Due to their large size, adult mantas don’t have many natural predators. Although, larger sharks and orca have been known to prey on them. Yet, the biggest threat they face comes from humans. Due to their low reproductive rate mantas are incredibly vulnerable to over-fishing.
These long-living animals are thought to live up to 50 years. Giving birth every 4-5 years, they’ll only produce between 4-7 pups during their lifetime.
GIANT MANTA RAY:
- SCIENTIFIC NAME: Mobula birostris
- FAMILY: Mobulidae (Manta & Devil Rays)
- MAXIMUM SIZE: 7m
- DIET: Zooplankton, krill & small fish.
- DISTRIBUTION: Worldwide in tropical and temperate waters. Found from the surface to depths of 1,000m.
- HABITAT: Spends long periods of time in the open ocean. Visits shallow coastal waters near coral and rocky reefs.
- CONSERVATION STATUS: Endangered
REEF MANTA RAY:
- SCIENTIFIC NAME: Mobula alfredi
- FAMILY: Mobulidae (Manta & Devil Rays)
- MAXIMUM SIZE: 5m
- DIET: Zooplankton, krill & small fish.
- DISTRIBUTION: Tropical and sub-tropical waters of the Indian and Pacific Ocean. Found from the surface to depths of 432m.
- HABITAT: Shallow coastal waters near coral and rocky reefs. Moves into deeper waters at night to feed.
- CONSERVATION STATUS: Vulnerable
Header Image: Frogfish Photography
Saba has an exciting new initiative to restore its coral reefs. This new project, running from 2024 to 2026, will focus on reviving key species in the island’s underwater ecosystems. With a collaborative team from the Saba Conservation Foundation (SCF) and Van Hall Larenstein (VHL) University of Applied Sciences, the project aims to restore both corals as well as sea urchins.
This initiative is centered around coral restoration, specifically reviving two essential coral species—staghorn coral (Acropora cervicornis) and elkhorn coral (Acropora palmata). By mapping parent colonies and using a technique known as coral gardening, SCF will create and maintain coral nurseries. These corals will eventually be outplanted at key reef sites around Saba to not only expand the number of coral colonies, but also provide essential fish habitat. The project focusses on installing coral nurseries, training staff with the newest techniques and starting with the restoration of key reef sites.
Reef Cleaners to the Rescue
It’s not just corals getting a makeover—this project also shines a spotlight on the essential role of grazers, particularly sea urchins. VHL is leading the charge on cultivating and restocking two key sea urchin species, West Indian sea egg (Tripneustes) and long-spined sea urchin (Diadema), known for their ability to keep algae in check. By removing algae, which are important competitors of corals, they help the coral to thrive. By restoring these “reef cleaners,” Saba’s project will give corals the breathing room they need to grow, setting the stage for a healthier, more balanced marine ecosystem.
From Tiny Urchins to Big Goals
The project will be funded as part of the Dutch Government’s Nature and Environment Policy Plan (NEPP) 2020-2030 for the Caribbean Netherlands, a comprehensive initiative aimed at conserving and restoring the unique natural environments of the Dutch Caribbean islands, including Saba, St. Eustatius, and Bonaire. This project is aiming for big milestones: build and maintaining coral nurseries, the expansion of urchin cultivation facilities, and the creation of a dedicated research center. By 2026, the project hopes to ramp up coral and grazer restoration, with the ultimate goal of extending these efforts across the Dutch Caribbean. By linking local initiatives to broader regional goals, Saba’s restoration project promises to leave a lasting impact on both the environment and the community.
Find out more about the DCNA at dcnanature.org.
Blogs
Reef-World marks two decades of marine conservation: strengthening impact amid coral reef threats
Empowering ocean stakeholders to tackle future challenges and ensure the survival of coral reefs and humanity
2024 marks the 20th Anniversary of The Reef-World Foundation’s tireless efforts for global coral reef conservation. The UK charity is the international coordinator of the UN Environment Programme’s Green Fins initiative, known as the leading voice in sustainable marine tourism. Today, Reef-World released its 2023-2024 Impact Report outlining a year of substantive growth and impact in its marine conservation programmes.
Impact Report Highlights:
- Impressive improvements in environmental behaviours to protect coral reefs by the marine tourism industry as the global participation of Green Fins increases.
- Continued capacity building for government and NGO staff to effectively manage marine tourism activities in Asia, Caribbean and Red Sea regions.
- For the first time in Green Fins’ 20-year history, tourism operators have achieved ‘Best Environmental Performer’ status by demonstrating the lowest possible environmental impact in their environmental assessments. In 2024, three dive operators achieved this challenging milestone.
- Significant increases in global participation of Reef-World’s innovative digital conservation tools.
- 138 Green Fins dive operator members achieved the strict threshold for PADI Eco Center recognition.
- Developed four new educational materials and translated two into 16 languages to support the marine tourism industry in achieving sustainability targets.
- Establishing a new Reef-World Development strategy and recruiting new roles – Development and Programmes Managers.
- Reef-World’s board welcomes new Chair and Trustees strengthening organisational leadership.
Reef-World started as a one-person mission to inspire and empower communities to act in conserving and sustainably developing coral reefs and related ecosystems. Today, the team of 12 continues to meet this mission by inspiring and empowering the global marine tourism community to be exemplary sustainability leaders by using the Green Fins guidelines and tools to simultaneously use and protect the world’s precious reefs.
In April 2024, the fourth global coral reef bleaching event was confirmed. Reef-World’s work has never been more urgent as the marine environment, and the benefits they provide humanity, continue to be eroded by global threats. The reduction of local threats, like those from the marine tourism industry, is an essential step to ensuring a future where coral reefs survive and continue to support the millions of people who depend on their ecosystem benefits. Reef-World’s work buys time for coral reefs and related ecosystems to be resilient to the impacts of global threats.
“Right now our corals are facing the greatest fight of their existence as the terrifying predictions of the steps towards their complete extinction are starting to come true. But all is not lost, reefs are resilient and they have existed on this planet for millions of years. We must take action now, to buy time for reefs by reducing threats facing them and allowing them to react and adjust to the changing environment they need to survive in.” – Chloe Harvey, Executive Director
Looking Forwards:
Like coral reefs, the Reef-World team needs to be resilient in the face of the complex challenges of the conservation sector. Reef-World has invested significantly in developing a Culture of Care to ensure the well-being of its team on a daily basis, continuing to be an exemplary employer to enable its team to best achieve the mission for coral reef conservation.
With the foundations of a Culture of Care and organisational development laid, Reef-World is emerging from the end of a natural organisation life cycle, that brings the challenges of growth and scale, stronger than ever. With a new strategy in place to generate much needed resources, Reef-World is excited for the opportunities to leap forward, continue to scale our impact and lean into new innovations and untapped opportunities for marine conservation.
We continually strive to become a forward-thinking organisation that delivers on our goals and commitments to our stakeholders with fresh approaches and not being afraid of steering away from a “normal approach.” This approach is not only applied to our programmes of work but also internally and carries over to our Culture of Care for our team.” — JJ Harvey, Operations Director
The Reef-World Foundation is immensely grateful for the continued support of its grant funders: UN Environment Programme, IUCN’s Blue Natural Capital Financing Facility, Adventure Travel Conservation Fund, PADI Aware Foundation, and World Nomads Footprints Program.
Reef-World would also like to express its gratitude to international partners whose vital support has resulted in significant tangible benefits for our work and mission: PADI; Professional SCUBA Schools International (PSS); Explorer Ventures; 1% for the Planet; ZuBlu; Snorkel Venture, GSTC; Dive O’Clock; Seven Dragons; DiveAssure and Eco Beach, without whom these achievements would not be possible.
The full 2023–2024 Annual Impact Report is available on Reef-World’s website.
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