reef manta ray, ©Shiyam ElkCloner

Many Threats for Manta Rays

Defenders calls for Endangered Species Act protection for all three species of manta rays

At up to 23 feet wide and 5,300 pounds, calling a manta ray “giant” is an understatement. Manta rays have the biggest brain of any fish, so underwater genius is more like it. Disproportionately large as compared to the rest of its body, a manta ray’s brain more closely resembles that of an equally large mammal. Though enormous, these planktivores are truly gentle giants. Scientists’ best guess puts a manta ray’s lifespan at 40-50 years, but, as scientific tracking of individuals increases, we could find that the massive fish live as long as 100 years.

Three different species – all needing protectionmanta ray, © Konstantin Tkachenko/Marine Photobank

As its name suggests, the giant manta ray is the biggest ray out there. While the Caribbean and reef manta rays are slightly smaller, they are still massive, and can reach more than 16 feet wide and 3,000 pounds. Scientists believe that many of the manta rays that they originally considered giant manta rays are actually a similar, but genetically and physically distinct third species, tentatively described as the Caribbean manta ray.

Earlier this year, Defenders of Wildlife submitted a petition to the National Marine Fisheries Service (NMFS) asking the agency to protect the giant manta ray, reef manta ray, and Caribbean manta ray (all known manta ray species) by listing them as endangered, or at least as threatened, under the Endangered Species Act (ESA). In 2013, the United States supported the successful listing of all manta ray species under the Convention on International Trade of Endangered Species (CITES) Appendix II, which regulates but doesn’t ban trade. The CITES listing was a positive step in the right direction, but mantas need greater protection as habitat loss and overfishing continue to threaten their existence.

As coral reefs disappear, so do mantasmanta ray on cleaning station, ©KonstantinTkachenko

Manta rays live around the world in tropical to temperate waters. The giant manta ray migrates more than its smaller counterparts, and is more widely distributed thanks to its greater tolerance for cold, deep water. Reef manta rays prefer more tropical waters and stay closer to shore, oftentimes having populations focused around a single island. Caribbean manta rays have the most constrained range, with all populations existing in the Gulf of Mexico, southeast United States, and, of course, the Caribbean. No matter their location, all mantas rely on coral reefs, which make up only 0.2% of the marine environment, but house 25% of all marine life. The fish species that live around reefs provide “cleaning stations,” where they help rid the rays of parasites – a process that can take up to eight hours, but benefits both the mantas and the fish. Coral reefs also serve as important feeding and breeding locations for mantas. Yet as coral reefs are quickly disappearing due to climate change, manta rays are losing this vital habitat. Climate change also affects the amount of plankton in the ocean, which is a big problem for a giant fish that feeds exclusively on these tiny sea creatures.

From shark finning to manta gilling

The most alarming threat facing manta rays is targeted overfishing due to the increasing trade of manta ray gill plates. Manta rays have recently become victim to an all-too-familiar exploitation, where a big animal is killed for a small, but very lucrative part of its body. For manta rays, that part is their gill plates, which filter plankton out of the water as the rays use their horn-like fins to funnel water into their large mouths. This filtering process has likely led to the unsupported, recent belief in Chinese medicine that eating dried and crushed manta ray gill plates detoxifies human blood and aids in curing everything from chicken pox to cancer. Manta ray meat is of little value, but these false medical claims have led to one pound of manta ray gill plates being worth more than $300, and a mature giant manta ray can yield up to 15 pounds of dried gill plates. As other valuable fish stocks become depleted, fishermen are now tapping into mantas, targeting them not only for their gill plates, but also as a cheap substitute or filler for shark fin soup.

Manta rays reproduce slowly. Some mantas don’t reach sexual maturity until they’re 15 years old, and even then they only typically have one pup every two to five years. This means that they can’t bounce back from the decimation wrought by overfishing. They are literally being pulled from the oceans faster than they can reproduce. Even with the strictest protections, it will take decades for manta rays to recover from the unsustainable overexploitation they have experienced. As population numbers continue to plummet, an ESA listing would provide increased legal protections for manta rays to help ensure their survival, including a focused recovery plan identifying specific management measures that could be taken to help mantas rebound to healthier population levels. With our petition to NMFS to list the giant manta ray, reef manta ray, and Caribbean manta ray, we strive to protect these gentle giants from the very real threat of extinction. We still have so much to learn about these mysterious and fascinating creatures, and their loss would be a tragedy. Our similar petitions to NMFS over the thorny skate, smooth hammerhead shark, and bigeye thresher shark have been successful, and the agency has begun status reviews as the first steps in granting these species protection. We hope to have a similar positive outcome for our petition to list manta rays, and should hear from NMFS in early 2016.

A Whale of a Shark

Another type of gentle marine giant, whale sharks can grow to be more than 45 feet long! Yet these creatures also face a number of threats.

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31 Responses to “Many Threats for Manta Rays”

  1. Tammy Sayman

    Why do humans think they need to destroy everyone other living thing on this planet. It need to stop now.

    • Elizabeth Simpson

      Simply put fear, being unaware! Look how we were able to domestic felines, wolves, etc. This proves that not all humans feel the need to destroy every other living creature on this planet. The smell of fear, which an animal can sense is what causes critters to react in a threatening way. This is what I believe. E

  2. Cate O'Rorke

    Killed for their gills?!!!?? Savagery is not a label to be proud of! Tammy is right. Too many humans do not understand holistic life styles. They’re happy to plunder, usually for personal financial gain, without considering the future of our planet. BE KIND to all living things. Even those which are difficult to live with. Find intelligent ways to manage problems.

    • Elizabeth Simpson

      “They’re happy to plunder, usually for personal gain etc.” is what for the most part what this is all about, the big pharmaceuticals in particular, suppress the advice of holistic practices, they are hurting not only us but their very own heirs. I believe in karma so i pray for for all those that are so greedy and uncaring. To do otherwise I believe would only hurt me. E

  3. Stephanie Miyashiro

    I support protecting biodiversity on earth.The cure for an ailment may be found in an obscure feature of some plant, animal, insect, etc. Life is quite miraculous. I love and am amazed by life on earth. So much still to discover and learn. Thank you, Creator.
    Stephanie

  4. Colleen Coleman

    The killing of beautiful and intelligent Manta Rays must end. They must be placed on the Endangered Species Act. We need to stop destroying the oceans and all inhabitants that live within the ocean.

  5. Beverly Dahlen

    It’s very important to protect these creatures from superstitious claims that are made by some people that the gills are valuable for healing. I would prefer letting scientists make decisions about drugs based on evidence.

  6. Ann Sturdivant

    The Manta Ray must have help by placing it on the Endangered Species Act.
    They are a very special animal as are all wildlife is.

  7. Janett Vale

    I had a wonderful experience in the Carribean meeting manta rays. I encourage everyone to support efforts to protect them

  8. Margaret rose kelly

    I think that we,mankind better wake up and smell the coffee before it is too late for us and all endangered sea creatures that are not only beautiful but have the right to flourish without us taking them out of the water,killing them and also not putting what is needed to protect their ecosystems that are necessary for their survival.We as humans are not looking at the big picture. Their is also much poverty in the world that comes into play in the killing of these poor defensless creatures. we need to stand beck and not be so self absorbed -selfish

  9. Carol apumadera

    I agree. Man needs to leave GOD’S creatures
    Alone.
    They have a right to live, like we do.
    Stop killing the Wolves, Bears, Turtles, All the
    Ocean Creatures, all creatures.
    I’ve been told that the Government is having
    The animals killed to thin out the animaks, that there are too many.

  10. Rebecca Richardson

    The Chinese are known for their stupid ideas about medicine–including aphrodisiacs, killing entire animals for nothing. When did the Chinese brain shrink? Once upon a time their civilization was magnificent.

  11. Terry Goewert

    The horror of killing innocents creatures for profit for stupid reasons will be the end of our planet. I just want to cry.

  12. Nancy Lowe

    Thank you so much for your selflessness. The animal people you help protect thank you most.

  13. JOANNE PARIS

    Thank you so much for all you have done and continue to do!

  14. Sheila Miller

    Thank you for protecting the manta rays. All the sea creatures need our protection in order to survive. Keep up the wonderful work!

  15. GABRIELA VARGAS

    MUCHAS GRACIAS POR ESTOS ARTÍCULOS E INFORMACIÓN TAN IMPORTANTE PARA TODO EL MUNDO. DEFINITIVAMENTE EL TRABAJO BRILLANTE DE TODOS SUS ABOGADOS EN FUNCIÓN DE TANTAS ESPECIES ES TRASCENDENTAL E INDISPENSABLE POR LA VIDA Y POR LA FORMACIÓN DE SOCIEDADES MÁS EVOLUCIONADAS. LOS TIBURONES Y LAS RAYAS SON UNA ESPECIE INCREÍBLE Y SU TRABAJO EN EL MAR ES INDISPENSABLE, YA QUE SON LOS LIMPIADORES DE LOS OCÉANOS, SIN TIBURONES PROBABLEMENTE SE TERMINE LA VIDA.

  16. Heidi

    Stephen Hawking had it right when he was quoted as saying “People are getting dumber and dumber”……NEED WE SAY MORE????

  17. Darren Liebman

    Thank you for fighting to protect the planet and its beautiful creatures!

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