The Aquarium’s Marine Conservation Action Fund (MCAF) recently provided funding that allowed researchers with the Manta Trust to tag manta rays in the Pacific Ocean. Our Facebook community helped name the two females—Sylvia and Eugenie! This post follows up on Sylvia and Eugenie's whereabouts, thanks to the data from those satellite tags.

Our online naming contest was a great success, and ever since then we've been waiting to find out where Sylvia and Eugenie are spending their time. This is critical information that can help inform conservation efforts for manta rays off Mexico and around the world.

A frame from a beautiful underwater video of Josh tagging the manta rays

Researcher Josh Stewart took time off from his field studies to offer a little background about the project and the Aquarium's involvement through MCAF.



Josh mentioned that he would share the data on Sylvia and Eugenie as soon as possible. Well, the wait is over!

The researchers have gleaned important information from those tags and compiled the data in an impressive interactive map over at DataMares. Head over there to dive into this pool of data. You'll also find helpful tips for navigating the map, including ways to single out Sylvia and Eugenie's movements!

Go to the map




If you want to learn more, check out Josh's guest posts about this manta research:

• Read a first-hand account of what it's like to tag these massive animals, and 
• Learn why these research endeavors are so important, and
• Watch an unbelievable underwater video of this field work in action.

Explore other projects supported by the Aquarium's MCAF program, all supporting grassroots research around the world to study and protect animals and habitats of our blue planet!

• Leatherback sea turtle nest protection and relocationin Indonesia
• Tackling a growing threat to manta rays in Sri Lanka
• Measuring a reef's resilience to climate change in the Indian Ocean
• Studying the impact of flooding on Indus River dolphins in India and Pakistan
• Protecting sea turtles in Costa Rica
• Studying whale sharks in the Gulf of Mexico after the Gulf Oil Spill

The Aquarium’s Marine Conservation Action Fund (MCAF) recently provided funding so researchers with the Manta Trust could tag manta rays in the Pacific Ocean. The researchers invited Aquarium fans to help them name two of those tagged rays. Thanks to everyone who submitted names on our Facebook page. We have a winner! Find out more about the names, the winners and the program in these statements from the Aquarium’s President and CEO Nigella Hillgarth, PhD, and our friends at the Manta Trust. 


From Nigella:
We received many great entries for the manta ray naming contest and I am excited to report that the Aquarium’s Conservation team and the Manta Trust have chosen the winners.

The two manta rays, satellite tagged by the Manta Trust and with support from the Aquarium’s Marine Conservation Action Fund will be named Sylvia and Eugenie for world-renowned marine scientists Sylvia Earle, Ph.D., and Eugenie Clark, Ph.D. Congratulations to the winner, Christine Archer, and thanks to all for your submissions!

The Aquarium is proud to have partnered with the Manta Trust in this contest, and more importantly, to have supported their work to protect mantas across the globe through our Marine Conservation Action Fund. By partnering with ocean heroes such as Josh Stewart of the Manta Trust, the Aquarium is helping to launch important conservation projects around the world, and to inspire the next generation of ocean stewards.”

Manta ray | Photo: D. Fernando, Manta Trust

From the Manta Trust:
We were ecstatic to receive so many naming suggestions from enthusiastic New England Aquarium fans, and we're happy to report that the final names for our two satellite-tagged manta rays have been selected. Sylvia Earle and Eugenie Clark are giants in the marine science and conservation fields, so it seems fitting that they should have two literal giants named after them and collecting valuable data that is directly supporting science and conservation. Thanks to the support of the Aquarium's Marine Conservation Action Fund, Sylvia and Eugenie are currently swimming around the Pacific Ocean after being tagged at Mexico's Revillagigedo Islands.

Manta ray swims with researchers. A screen grab from a moment in this underwater video.

We are excited to be partnering with the Aquarium on a number of manta conservation initiatives around the world, and are grateful for their continued support.

Learn more about this project by Manta Trust to tag rays, and more. Catch up on this recent series of posts with some terrific guest posts from the scientists:

• See what it's like to tag these gentle giants, Part 1, Part 2 and Part 3
• See how visiting fish markets helps scientists study these devils in distress, Part 1 and Part 2
• Learn what it takes to build a global strategy to study and protect manta and devil rays

Discover other projects supported by the Aquarium's MCAF program, all supporting grassroots research around the world to study and protect animals and habitats of our blue planet!

• Leatherback sea turtle nest protection and relocation in Indonesia
• Tackling a growing threat to manta rays in Sri Lanka
• Measuring a reef's resilience to climate change in the Indian Ocean
• Studying the impact of flooding on Indus River dolphins in India and Pakistan
• Protecting sea turtles in Costa Rica
• Studying whale sharks in the Gulf of Mexico after the Gulf Oil Spill

This post is one of a series on projects supported by the Aquarium’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists and grassroots organizations all around the world as they work to address the most challenging problems facing the ocean.  

The Manta Trust has received funds from MCAF to support manta ray research around the world. Its scientists recently asked the Aquarium community to help name two recently tagged rays. Thanks to everyone who submitted names! A winner will be announced Tuesday, Sept. 16, 2014. 

In this post, guest blogger is Daniel Fernando of the Manta Trust explains his focus of research: documenting the mobulid rays landed in three Sri Lankan fishing communities. Read Part 1 of this series.


My work focuses on the fisheries surveys in Sri Lanka, and thanks to a generous grant from the Aquarium's Marine Conservation Action Fund (MCAF), I was able to carry out intensive field surveys at three primary landing sites. The most interesting and largest of these three survey sites is Negombo, where both manta and mobula rays (collectively called “mobulids”) are landed as bycatch from the skipjack tuna gillnet fishery.



The survey begins with a 3 a.m. wake-up, followed by an hour’s drive to the market. At this time the market is already bustling with fishermen unloading their catches, auctioneers shouting their prices and buyers scurrying around with their purchases—all of this accompanied by the smell of fresh and rotting fish. Due to the lack of refrigeration on boats and any proper preservation techniques, much of the landed fish is already spoilt. On the positive side, nothing goes to waste—all the rotten fish, along with guts and other discarded remains are dried and sold as animal fodder or cheap dried fish.

The Aquarium’s Marine Conservation Action Fund helped scientist, Daniel Fernando document the impact of the manta and mobula ray fishery by collecting data at markets, such as this one in Sri Lanka.

While ensuring that I do not get hit by a shark or ray chucked off a boat, I collect as much data as possible. I begin by logging all the mobulid species landed, their gender, maturity and collect tissue samples from vital species such as mantas. Other information such as sale prices, current demand and fishing locations is also logged since it all helps obtain a better understanding of the entire fishery. Some of this data has already helped influence international policy decisions for better control and management of the trade of manta gill plates.


But this is just one market in one country and my work is not restricted to Sri Lanka. In fact I am conducting another project, funded by the Save our Seas Foundation, to create a global mobulid identification guide. This project was initiated due to ambiguity in identifying the extremely similar looking mobula species, one of the main reasons behind their inadequate protection. One component of this guide also includes a genetic kit, for which tissue samples are required from all corners of the world. Global collaboration on such a project is an absolute necessity, and MCAF’s support of other mobulid projects, around the world is critical as it not only expands data collection but also enables projects such as mine to obtain samples from all regions of the world in order to create an international, robust genetic identification kit. This kit, once produced, will be available to researchers in the field expanding mobulid data collection, and to international trade officials working to ensure the implementation of regulatory bodies such as CITES.

I hope that this initiative, along with the long-term fishery surveys, will provide us with the data and means necessary to ensure the survivability of these vulnerable species for generations to come!

Photo: The Manta Trust

Daniel Fernando is Associate Director at the Manta Trust, a PhD student at Linnaeus University and a grantee of the Aquarium’s Marine Conservation Action Fund.

He lectured at the Aquarium during the 2013 Aquarium Lecture Series. Watch his talk on the Aquarium's YouTube channel.







Learn about other projects supported by the Aquarium's MCAF program, all supporting grassroots research around the world to study and protect animals and habitats of our blue planet!

• Leatherback sea turtle nest protection and relocation in Indonesia
• Measuring a reef's resilience to climate change in the Indian Ocean
• Studying the impact of flooding on Indus River dolphins in India and Pakistan
• Protecting sea turtles in Costa Rica
• Studying whale sharks in the Gulf of Mexico after the Gulf Oil Spill

This post is one of a series on projects supported by the Aquarium’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists and grassroots organizations all around the world as they work to address the most challenging problems facing the ocean. 

In this post, guest blogger is Daniel Fernando of the Manta Trust explains how scientists are working to study and protect beautiful manta rays in the wild. The Manta Trust recently asked the Aquarium community to help name two recently tagged rays. Thanks to everyone who submitted names! A winner will be announced Tuesday, Sept. 16, 2014. 




Manta and mobula rays, commonly referred to as devil rays due to their two “horns” or cephalic fins on their head, are among the largest and most charismatic fish in the ocean. The 11 mobulid species form part of the elasmobranch family and are therefore closely related to sharks, and similarly, are greatly sought after by avid scuba-divers intending to check them off their bucket-list!

Sadly, they are also highly threatened and in dire need of both national and international protection throughout their range. This is mostly due to the fact that over the past decade, well manipulated marketing coupled with the declines of more desirable fish stocks has driven an international trade for their dried gill plates – the tough cartilaginous structures that enable mobulid rays to filter plankton from the water column – resulting in the development of a target fishery for these species.

Manta and mobula rays are killed for their gill plates.

These gill plates are used in Chinese Medicine.

The dried gill plates are sold in Chinese medicine, claiming to purify blood and cure ailments such as the common cold, chicken pox and asthma, among others. There is no scientific proof to validate any of these claims and recent studies even show that gill plates might be harmful when consumed in large quantities, due to the accumulation of certain heavy metals, such as arsenic. Most consumers of this “medicine” are however not even aware that it originates from a threatened species, highlighting the need not just for controls on the trade, but also an increase in awareness among the public.

Given the extremely conservative life cycles of mobulids—due to their late maturity, low fecundity, slow growth rates and few natural predators—any form of fishery that targets these species will most certainly be unsustainable. However, in order to bring about the regulations necessary to adequately protect and manage these species, we require a great deal of information to scientifically back any claims we make. We need to know about the biology and ecology of these rays and obtain an idea of their global population sizes – which is not as easy as one might think!

There are three main areas of focus to obtain such information: 1) living populations, 2) fisheries and trade, and 3) genetics and other laboratory techniques. The study of living populations is by far the most popular and best recognized by most people, thanks to amazing underwater photographs of both manta and mobula rays from some of the most exotic locations in the world, such as the Maldives, Hawaii, Yap, and Borneo, just to name a few! These studies employ techniques such as photo-identification, which makes use of unique spot patterns, similar to fingerprints, on the undersides of manta rays when they visit well-known feeding or cleaning aggregation sites.

Manta aggregations such as these are focused around feeding or cleaning sites.

The smaller mobula rays on the other hand prove to be slightly trickier to see in the wild and this is where our second area of focus helps provide some degree of information on these evasive species. Through comprehensive fishery surveys in countries where these rays are caught as either target or bycatch species, we are able to collect large quantities of data pertaining to species demographics, sizes, age at maturity and so on. All of this data helps shed light into their mysterious lives and provides us with data required to help control the fisheries of these vulnerable species.

Finally we get to the genetics! Colleagues working tirelessly in laboratories around the world are responsible for analyzing the large number of tissue samples collected both from living populations and fisheries specimens. The analyses encompass a wide range of techniques from genetic barcoding to identify specimens down to species level, stable isotope analyses to determine their primary food sources and foraging regions, and even to determine how distinct each population of mobulid rays are and when exactly, on an evolutionary scale, they became a separate species. Genetic investigations such as these provide us with critical data that not just allows us to learn more about these animals but also help enforce international regulatory bodies such as CITES and CMS via the use of genetic identification tests in trade regulation.

Research data from living populations, fisheries and genetics is what enables us to gain a deeper understanding of these animals and create a clearer image of the threats these species face, which in turn supports and facilitates the introduction of appropriate management controls and methods to help save these species. Ultimately, the conservation of species such as mobulid rays, which are not constrained by political geographic regions, is only feasible through an international multifaceted approach using methods ranging from the implementation of marine protected areas (MPAs), the introduction of local and international management measures (such as CITES and CMS), seeking alternative livelihoods for fishermen, and educating the general public and consumers about the reality of the situation.

Photo: The Manta Trust

Daniel Fernando is Associate Director at the Manta Trust, a PhD student at Linnaeus University and a grantee of the Aquarium’s Marine Conservation Action Fund.

He lectured at the Aquarium during the 2013 Aquarium Lecture Series. Watch his talk on the Aquarium's YouTube channel.







Learn about other projects supported by the Aquarium's MCAF program, all supporting grassroots research around the world to study and protect animals and habitats of our blue planet!

• Leatherback sea turtle nest protection and relocation in Indonesia
• Measuring a reef's resilience to climate change in the Indian Ocean
• Studying the impact of flooding on Indus River dolphins in India and Pakistan
• Protecting sea turtles in Costa Rica
• Studying whale sharks in the Gulf of Mexico after the Gulf Oil Spill

This post is one of a series on projects supported by the Aquarium’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists and grassroots organizations all around the world as they work to address the most challenging problems facing the ocean. This series focuses on a satellite tagging project underway by the Manta Trust. Catch up with Part 1 and Part 2 of this series.

Guest blogger Josh Stewart of the Manta Trust recently shared some information about a scientific project to study manta rays. Catch up with his posts on the Explorers Blog:

• Read a first-hand account of what it's like to tag these massive animals, and 
• Learn why these research endeavors are so important.

Now that you know all about tagging these animals and what information scientists with Manta Trust are hoping to get from these devices, indulge yourself with a moment underwater with these researchers. This video lets you swim deep below the surface among these massive animals with wingspans of up to 7 meters (that's nearly 23 feet!). Watch as the scientists slip behind the animals and plant the tag as gently as possible—with little reaction from the ray.


Tagging an Oceanic Manta from Josh Stewart on Vimeo.

And now that you're thoroughly enthralled by these animals, we hope you'll head over to our manta Facebook post and submit a name for two of these beauties! The rays we're naming are both females. The Aquarium's Conservation Department will consider all the names posted on our manta Facebook posts between today and Tuesday, September 9. Get creative. Think about names that might be educational, or touch on conservation issues, or their beauty. The winners will be announced on September 16, and they'll get a beautiful plush animal from our Gift Shop to remind them of their special connection to "their ray" soaring through the Pacific Ocean. Good luck, we can't wait to see what you come up with.

Learn about other projects supported by the Aquarium's MCAF program, all supporting grassroots research around the world to study and protect animals and habitats of our blue planet!

• Leatherback sea turtle nest protection and relocation in Indonesia
• Tackling a growing threat to manta rays in Sri Lanka
• Measuring a reef's resilience to climate change in the Indian Ocean
• Studying the impact of flooding on Indus River dolphins in India and Pakistan
• Protecting sea turtles in Costa Rica
• Studying whale sharks in the Gulf of Mexico after the Gulf Oil Spill

This post is one of a series on projects supported by the Aquarium’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists and grassroots organizations all around the world as they work to address the most challenging problems facing the ocean.  

Part 1 of this series focused on how scientists tag these giants. Here's more about the scientific tagging project from guest blogger Josh Stewart of the Manta Trust. 

The Aquarium’s Marine Conservation Action Fund helped support the satellite tagging of manta rays off the coast of Mexico, led by Josh Stewart of the Manta Trust.

Understanding how these gentle giants move around in and use their environment is a pressing and unanswered question. Manta rays are threatened globally by targeted fisheries and bycatch, much of which is driven by the gill plate trade (read more here). Currently we know almost nothing about the population structure and connectivity of oceanic manta populations, which have significant implications for the impacts that fisheries are having on mantas, as well as the practicalities of effective conservation and management action. Luckily, mantas are protected from direct catch under Mexican law, but they are still impacted by harmful fisheries interactions and bycatch in Mexican waters.

Tagging oceanic manta rays

We know of two manta hotspots in Pacific Mexico: the Revillagigedo Archipelago, long a favorite of dive tourists, and Bahia de Banderas, where we've recently discovered what seems to be a sizeable manta population. One of our goals is to determine whether these two 'hotspots' are part of a single, linked population that migrates seasonally between the two regions, or if they represent separate populations. Evidence of fisheries interactions, such as gear entanglement, scars from fishing lines, and missing cephalic and pectoral fins, is more frequent in mantas observed at the coastal hotspot in Bahia de Banderas, suggesting that mantas using this area may be more susceptible to bycatch or other negative impacts of fisheries.

Understanding the linkage between these regions, as well as the habitats that the mantas here are using and visiting frequently, will help us generate strategies for reducing and mitigating these impacts. Furthermore, the tag tracks will show us how large the geographic ranges of these populations are and, importantly, whether they are staying within Mexican waters or traveling to regions where mantas are not protected.

While we'll be biting our nails until the tags pop off and transmit their data in November, the New England Aquarium is taking the opportunity to properly prepare for the satellite tracks by naming the two mantas that are currently sporting some new MCAF-funded fashion accessories. Stay tuned for details on how you can suggest names for these mantas and vote on your favorites! We'll keep you updated on where the mantas went and what this means for manta conservation come this fall.

Josh Stewart is the Associate Director of the Manta Trust, a PhD student at Scripps Institution of Oceanography, and a grantee of the Aquarium’s Marine Conservation Action Fund.

This post is one of a series on projects supported by the Aquarium’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists and grassroots organizations all around the world as they work to address the most challenging problems facing the ocean.  

Between September 5 and September 9, we are hosting a naming contest for two female mantas tagged in this post. All names submitted on our manta Facebook posts will be considered. Here's more about the scientific tagging project from guest blogger Josh Stewart of the Manta Trust. 

The Aquarium’s Marine Conservation Action Fund helped support the satellite tagging of manta rays off the coast of Mexico, led by Josh Stewart of the Manta Trust.

Tagging a manta is not a particularly easy task. Setting aside the technical details of the tags themselves, the days (and days and days) of travel required to reach study sites, and the hours spent in the water each day, when the mantas actually arrive, the challenge of tagging truly begins.

Oceanic manta rays, our species of interest, can reach up to 7 meters in disc width, or wingspan, and weigh several tons. When you get this big, not many creatures are able to eat you. And so manta rays have effectively lost all of their active defenses (think spines or barbs in their benthic relatives, stingrays), and now rely solely on their immense size and perhaps surprising agility to keep predators at bay. As a result, mantas have few natural predators—mostly large sharks—and the only instances we know of fatal predation are when orcas have stumbled on an unlucky and apparently tasty-looking manta. Orcas aside, sharks tend to take chunks out of the pectoral fins of mantas, and always appear to attack from behind, based on bite marks and scarring patterns observed in mantas around the world.

Manta rays (Manta alfredi) are thought to have the biggest brains of all the fish in the ocean | File photo: Guy Stevens

So it's safe to say that mantas sometimes get a bit nervous when something approaches them quickly from behind. Funny, then, that this is exactly where we need to be when we tag a manta. So how do we do it, without our study subject taking off at high speed the minute we approach? Patience, mainly, and gaining the trust of a two-ton giant 60 feet below the surface of the ocean.

As I jump into the cool, crystal-clear blue off San Benedicto Island in the Revillagigedo Archipelago, Mexico, a watery abyss opens up beneath me. Despite 100-foot visibility, the bottom is nowhere to be seen, while the cathedral-sized pillar known as The Boiler rises from the deep to my right. The Boiler is an attraction in itself, a dramatic volcanic pinnacle alone in the blue. But the main event here is the abundance of mantas, making The Boiler perhaps the best site in the entire archipelago to see them.

Five minutes after dropping in, our first manta appears: a 5-meter female with a gnarled, short tail and the scars of an oceanic giant that has been around the block a few times. She approaches the divers cautiously but with clear interest. This is one of the most fascinating aspects of being in the water with a manta: the unmistakable curiosity in their eyes, the obvious desire and willingness to interact with bubbling visitors. As she loops above their heads, coming close enough to touch and inquisitively looking each and every one of them over, a second manta appears out of the blue. This one is a black manta, the same species as the first but with almost no white markings on its entire body; the stealth bombers of the deep. Soon two more giants have joined in, and we're surrounded by curious mantas that one can't help but feel are playing with us, enjoying our company.

Now comes the hard part. I pick two mantas that I want to tag: the big female that arrived first and a male that joined in later on. I make my way toward the female, who is now swimming in wide circles out into the blue and back toward The Boiler. I swim to where I think she'll intercept me, and wait for her to approach; she passes over my head and swims through my bubbles, apparently enjoying the way they must tickle her belly.

She starts to swim off but I don't chase her, I let her turn back around and come to me, making tighter and tighter circles until she's passing by me every 30 seconds or so. On her fifth or sixth pass I try swimming after her slowly, positioning myself above and behind. She seems fine with it, but I stop kicking and let her make another loop. On the next pass I do the same again, this time sticking with her a little longer. She seems to be getting comfortable with me swimming behind her, but I don't push my luck.

One more pass and it's time; I "load" my tagging pole, extending the thick rubber band and grabbing the top of the spear close to the tag. As she passes by me, I slowly swim behind her, but I'm still too far to apply the tag: I want the tag to be about a foot above her pectoral fin when I release it and now I'm about 4 feet away. I kick harder and pick up speed, holding my breath and hoping she doesn't spook: 3 feet… 2 feet… She's still very calm: 1 foot now… I aim my spear at the sweet spot and release, and the tag glides seamlessly into position. The manta barely flinches, and doesn't swim off despite having just been tagged. My colleague, Antonio Ruiz, a researcher and recent graduate of the University of Baja California Sur, follows and collects a tissue biopsy from her; still hardly a flinch.
(Watch a video of a manta ray being tagged here.)

A few minutes later I deploy the second tag on the male in much the same fashion. I'm often asked whether the tagging process hurts the mantas. Based on the reaction this time, it seems clear that they aren't too bothered by being tagged, but in other cases mantas that I've tagged have reacted by swimming off at top speed, so it does seem to vary by individual and by region. Now while I'm not a manta and I must admit I've never personally been tagged, I can say with some confidence that mantas do not feel pain in the same way that humans do, and being tagged would not "hurt" in the same way for a manta as it would for a human.

Humans have evolved complex nerve networks that serve as learning tools: the nerves in your fingers tell you not to touch a hot kettle because it will burn you, for example. Mantas haven't evolved in an environment with the same need for these 'pain' cues, and therefore they have much lower densities of nerve endings. Furthermore, while about 50% of human nerve endings are devoted to feeling pain, less than 1% of nerve endings in rays serve this purpose. The difference between tagging a manta and tagging a human is probably similar to the difference between pinching the skin on your elbow and pinching the skin on your triceps. So in cases where mantas react strongly to being tagged it's probably a result of being surprised, and in my experience this tends to happen more in regions where mantas are not as accustomed to divers.

Soon after the second tag is deployed we end our dive and head back to the boat. We do three more dives at the boiler, and on each dive we see the same two mantas that were tagged in the morning. Over the course of about eight hours, until the sun begins to set and we end our day's diving, the mantas continue to follow us around, swim over our heads, look us in the eye and practically touch us with the tips of the fins, as if wanting to see what these strange, bubbly creatures feel like. We tag two more mantas—both females—before the day is through, and just before surfacing on our last dive I look down and see a train of mantas below us, almost every one of them sporting a new tag. These tags, generously supported in part by the Aquarium's Marine Conservation Action Fund, will collect data on movements and diving behavior for the next six months, at which time they'll pop off and transmit their precious, archived data back to us via satellite.

Josh Stewart is the Associate Director of the Manta Trust, a PhD student at Scripps Institution of Oceanography, and a grantee of the Aquarium’s Marine Conservation Action Fund.

This post is one of a series on projects supported by the Aquarium’s Marine Conservation Action Fund (MCAF). Through MCAF, the Aquarium supports researchers, conservationists and grassroots organizations all around the world as they work to address the most challenging problems facing the ocean.   

Photo: M. Harding

The southeast Pacific Ocean supports a significant population of giant, oceanic manta rays (Manta birostris). These gentle giants are fully protected from harvest in Ecuador, but are highly threatened due to bycatch and overfishing in the neighboring waters of Peru. With support in part from the Aquarium’s Marine Conservation Action Fund (MCAF), an international team of scientists is working to change the fate of this species in Peru. The team, which includes staff from Planeta Oceano, the Manta Trust and WildAid collaborated with local fishermen and students to gather fishery landings data on mantas and their relatives, the mobula rays.

Kerstin Forsberg

Peruvian biologist Kerstin Forsberg, director of Planeta Oceano, presented the results of this research during a guest lecture at the Aquarium in the fall of 2013. Forsberg noted the team’s data showed that the majority of the captured mobula rays were juveniles and that several of the landed mantas were pregnant. Harvesting the rays before they can reproduce is not sustainable, given the already low reproductive rate of these species. Therefore, the team is using their findings to support a proposal for national protection of mantas and mobulas.


Protecting these species could prove to be a boon to the Peruvian economy. Research published last year in the journal PLOS ONE showed that over its lifetime, a live manta ray is worth up to $1 million to the tourism industry and only $40 to $500 dead. With the value of manta tourism in the global spotlight, Forsberg and Planeta Oceano are working with fishermen to build an ecotourism industry around these animals. Their pilot effort, which recently won a highly competitive award from Project Aware, will empower 10 artisanal fishermen to lead tours to view mantas in Peru. This approach will both increase the fishermen’s income and support manta ray conservation. With the steadfast efforts of manta advocates such as Kerstin Forsberg, there is hope that Peru will one day follow the lead of countries such as Ecuador, Mexico and most recently, Indonesia, in banning the targeted harvest of manta rays.



Read about Kerstin Forsberg’s visit to the Aquarium and her workshop for the Aquarium’s Marine Biologist in-Training students here.

To learn more about the efforts of Planeta Oceano to protect manta rays see Forsberg’s recent article for the Ocean Health Index.

This is a report on a project conducted by the Manta Trust and supported with a grant from the Aquarium’s Marine Conservation Action Fund (MCAF) in 2012. MCAF supports the Aquarium’s commitment to ocean conservation by funding small-scale, high-impact projects across the globe. Since its founding in 1999, MCAF has funded more than 100 conservation projects in 36 countries and has disbursed more than $600,000 to protect highly vulnerable species and habitats and to conserve marine biodiversity. 

Manta rays are massive and graceful animals. With widths reaching over 20 feet from wingtip to wingtip, and weighing in at up to 2 tons, the manta is the largest of the ray species. These huge animals feed on the smallest creatures of the sea, including tiny zooplankton and very small fish. In the past decade, scientists have learned a great deal about these magnificent animals. However, much remains to be known about their intelligence, their social lives and their role in marine ecosystems.

Manta rays (Manta alfredi) are thought to have the biggest brains of all the fish in the ocean. Much remains to be learned about the intelligence and social interactions of these fascinating creatures. Photo: Guy Stevens

Unfortunately, these fascinating creatures are gravely threatened by overfishing due to a growing demand for their gill rakers for use in traditional Chinese medicine. Gill rakers are the tough cartilaginous structures that protect the rays’ gills and allow them to strain plankton from the water. Although purported health claims about the gill rakers are not supported by science, the market for rakers continues to grow, heavily increasing fishing pressure on mantas and their relatives, the mobula rays. These ray species grow slowly and have a low reproductive rate. Consequently, this intense level of harvesting could be devastating to their populations.

Manta and mobula rays are being hunted at record levels for their gill rakers, the cartilaginous structures they use for feeding. The gill rakers are highly valued by the traditional Chinese medicine trade.

The Manta Trust, an organization dedicated to the research and protection of manta rays, is studying the impact of this growing fishery on manta and mobula populations. With a grant from the Aquarium’s Marine Conservation Action Fund (MCAF), Manta Trust project leader, Daniel Fernando surveyed fish markets in Sri Lanka, a major exporter of gill rakers. The purpose of these surveys was to assess the number of manta and mobula rays caught each year, so as to better understand and highlight the vulnerability of these animals.

Daniel Fernando noted that:

The data collected [in the surveys] is already being used to produce a scientific publication outlining catch rate of landed species in Sri Lanka. More importantly, data from this project [was] used to support a [successful] proposal to include manta rays in Appendix II of  CITES (Convention on International Trade of Endangered Species), [which will] help control and regulate the global trade of these species and improve their survival in the wild.

Ultimately, the Manta Trust hopes to use their research to support a ban on the export of gill rakers in Sri Lanka, which would significantly reduce the fishing pressure on these animals.

In addition to their fish market surveys, the Manta Trust is working on several other fronts in Sri Lanka to protect manta rays over the long term. They are conducting ocean surveys to identify key manta habitats such as nursery grounds and aggregation areas. This data will be used to advocate for marine protected areas for these critical habitats. The Manta Trust will also work with local communities to encourage sustainable alternatives to the manta fishery, such as promoting dive tourism. With these efforts the Manta Trusts hopes to secure a brighter future for these magnificent animals.

Learn more about the work of the Manta Trust on their website and Facebook page.