A Closer Look at Rays with Manta Trust’s Simon Hilbourne
SC: Where did your fascination for the ocean start and what experiences led you to Manta Trust?
SH: My name is Simon Hilbourne and I’m the Digital Media and Communications manager for the Manta Trust. I actually started off with the charity in the Maldives as a volunteer back in 2016. Since then I worked as the research officer for the Maldivian Manta Ray Project in Baa Atoll before taking on my current role in the wider Manta Trust network.
I’ve always loved the oceans. I grew up in Thailand so was fortunate enough to learn to scuba dive at a young age and I guess that interest and intrigue never really left. Whilst diving I learned to use an underwater camera and slowly taught myself more and more and my content improved.
SC: A lot of readers are here because of sharks, and unfortunately they are no strangers to the devastation of the fin trade, overfishing and bycatch. Manta and devil rays face eerily similar threats, namely the gill plate trade. Can you describe the connectivity of the gill plate and fin trade, and the progress that has been made thus far?
SH: The mobula gill plates are almost like shark fins' evil twin; the two trades have many similarities. Manta and devil rays have five pairs of gills which are used to respire and filter plankton from the water to feed on. Inside the gills are structures called gill plates. In recent years, a growing trend has been seen in the marketing and use of these gill plates in Asian Medicine. This practice is hugely wasteful, although manta and devil ray meat is consumed in some places, the overriding economic incentive for targeting or landing bycatch individuals is from the gill plates. The gills are dried and exported to Far East Asia where they are consumed as a tonic or in a soup called Peng Yu Sai.
SC: Is this a fisheries or consumer education issue, or both?
SH: Retailers claim that, just as mobulids use gill plates to filter plankton from the water, the same gill plates can aid in the detoxification and purification of the consumer by filtering disease and toxins from the body. However, there is no scientific evidence to support these claims. Worse still is that gill plates are not truly a Traditional Medicine - the demand has arisen due to product marketing by retailers, who have falsely ‘revived’ a remedy that never existed in the traditional literature. Additionally, being large, long-lived marine animals, mobulids contain high levels of toxins and heavy metals so consumers are likely doing themselves more harm than good.
There is certainly a consumer education issue here as people are not aware of the impacts of these fisheries and the fact that there is no medicinal benefit from consuming these products. However, even if the demand was completely removed, many manta and devil rays are caught as incidental bycatch and that would continue to happen. It would make it less lucrative to target these species but they will still be accidentally caught in large numbers. That's why we are working on studies looking at post-release mortality and entanglement prevention measures as well as working with fisheries to find ways to reduce bycatch (protected areas, changing gear types, etc.).
SC: Manta Trust is an organization recognized around the world for mobulid conservation and research, launching a wholistic and long-term plan, "the Global Mobulid Conservation Programme". Can you give us a look into the work Manta Trust is focused on?
SH: The Manta Trust started in the Maldives as the Maldivian Manta Ray Project before expanding to become a global network of conservative organisations working toward a common goal of seeing a world where manta and devil rays thrive in healthy, diverse marine ecosystems. In order to streamline these efforts, we established the Global Mobulid Conservation Programme to focus efforts on high mobula fisheries regions. Indonesia has put protection in place for manta rays but not devil rays and the accidental bycatch of mantas is still happening. There is still a lot more work to be done and changing government legislation and national protection is a long process.
SC: What questions are you trying to answer via research?
SH: There are still many baseline questions about manta ray ecology and biology that we do not know. Information about their reproductive strategies, where mantas give birth and their habitat use are still not well understood. Without this knowledge, it is hard to effectively guide conservation management plans.
SC: The relationship between mantas and tourism is delicate. Can you dive into the Maldivian Manta Ray Project and how that will help ensure ecologically responsible viewing practices?
SH: Giving people the chance to get into the water and come face to face with these magnificent animals is very important. We don't feel the need to protect or conserve things we don't have a connection with. Humans are quite visual so connecting with something without seeing it in real life is hard. However, tourism, if done in an unsustainable way, can be very detrimental. As a result, the Maldivian Manta Ray Project looked at how human behaviour of divers and snorkelers impacted manta rays. This work informed our 'How to Swim with Mantas' code of conduct which we have turned into a free multi-media toolkit available in several languages.
SC: Photography and diving plays an important role in the storytelling of your research. Tell us about one of your most impressionable encounters or discoveries.
SH: My number one manta encounter is still from Hanifaru Bay I think. There was a day back in 2019 when we had over 150 reef manta rays feeding on thick plankton soup. Often when you get such encounters, the visibility is very poor. On this day the water was strangely clear. It didn't stop there though! We had 2 or 3 different whale sharks pop up and join the feeding frenzy at different times and the icing on top was an oceanic manta rays joining the party too!
SC: Do you have a go-to camera set up for capturing the beauty of rays?
SH: As many photographers will tell you, the best camera you have is the one in your hand! Small compact cameras and action cameras have come on leaps and bounds in recent years so are very good options. For taking ID shots of manta rays, you are often under the manta rays photographing upwards against the sun which makes things a bit tricky. It's hard to get a shot of the spot pattern without it being blown out by the sun. To help here, using strobes or underwater flashes can be very helpful. Strobe photography is not always encouraged with marine wildlife however we haven't recorded any negative response in manta rays from flash photography. Having said that, firing a strobe repetitively very close to the mantas eye is probably not wise!
SC: Why is it important to protect all species of rays?
SH: Manta rays have been shown to fill a unique ecological niche role in transporting nutrients from the epi-pelagic region (slightly offshore shallow waters) to shallow coral reefs. This is done when the manta rays feed on plankton in one region and excrete in another. However, we aren't fans of trying to assign specific importance for a single species. There are millions of species out there, many of which don't have vital importance . Does not being able to assign a specific important role in the ecosystem warrant allowing their extinction? Manta rays make up just a small part of incredibly diverse tropical marine ecosystems and what they can offer is a gateway to conservation. Manta rays are enigmatic, beautiful creatures which are easier to make people fall in love with and want to protect. If we can do that, we can, by association, protect other species and their habitats at the same time.
SC: Much like Shark Cafe, Manta Trust also holds collaboration as a pillar. Please explain why developing partnerships is beneficial for ocean conservation efforts and specifically yours.
SH: The issues around marine conservation are vast and sometimes feel insurmountable. However, by working together and collaborating we can have a far bigger collective impact. That's why collaboration is one of the key pillars of our charity. Whether it's collaboration between researchers, between NGOs, or between industries, the more people we have working towards a collective goal, the more likely we are to achieve it.
SC: Let the people know how they can help Manta Trust, stand up against gill plate products, tips on choosing responsible tour operators, anything!
SH: There are many things that people can do to help the Manta Trust and our cause. Reading, learning and sharing knowledge with others is very important. Many people outside of the marine world don't know what a manta ray is or the threats they face. Additionally, choosing a sustainable tour operator if you are going on a manta ray tourism excursion is a great way to have a more responsible, educational and enjoyable manta ray encounter. Lastly, consider what you eat. Although you might not be eating manta ray meat or gills directly, one of the biggest threats to manta rays is their incidental bycatch by tuna fisheries as mobulids and tunas are often found in similar areas of the ocean. Selecting more sustainable seafood options like pole and line caught fish, or reducing your seafood consumption more generally is a great way to have a positive impact on the ocean and manta rays alike.
